Question: A 31-year-old man presents to the emergency department for fever, malaise, and cough. For the last week, his cough has been progressively worsening, and he has been noticing blood in his sputum. He denies any recent travel or sick contacts and infrequently smokes cigarettes. Approximately 5 weeks ago, he presented with similar symptoms and was found to have a right upper lobe lung infiltrate, a CD4 count of 40/mm^3, and an HIV viral load of 115,000 copies/mL. He was appropriately treated and discharged home. Four weeks after initiation of treatment, his CD4 count was over 400/mm^3 and HIV viral load was negligible. His temperature today is 102°F (38.9°C), blood pressure is 130/90 mmHg, pulse is 100/min, and respirations are 20/min. A radiograph of the chest demonstrates new nodules in the left upper lobe and hilar adenopathy. Which of the following is the most appropriate next step in management?

Continue current anti-retroviral treatment, antimicrobial, and anti-tuberculoid therapies

Determine drug sensitivities against the patient’s pulmonary infection

Start high-dose glucocorticoid treatment and discontinue antiretroviral therapy

Answer: Continue current anti-retroviral treatment, antimicrobial, and anti-tuberculoid therapies

Explanation:
This patient with recently diagnosed HIV and tuberculosis infection (upper lung lobe infiltrate) is presenting with worsening symptoms after being appropriately treated. Worsening of symptoms after initiation of these therapies is concerning for immune reconstitution inflammatory syndrome (IRIS), which is managed by continuing current combined antiretroviral medications, antibiotics for opportunistic infections and symptom management.

IRIS describes a paradoxical worsening of a patient's underlying infection after initiating antiretroviral therapy for patients with HIV. IRIS can also occur in HIV-uninfected patients with tuberculosis or leprosy who are started on antimycobacterial treatment. The pathogenesis of IRIS is unclear, but in patients with HIV, antiretroviral therapy increases the amount of CD4+ T-helper cells, which can lead to an exaggerated inflammatory response (e.g., increased cytokine release) towards the infection. Thus, there is a paradoxical worsening of the infection symptoms. When patients have a paradoxical worsening of their symptoms in the setting of starting their antiretroviral therapy, the therapy should be continued with symptomatic management (acetaminophen for fever).

Nelson et al review IRIS. They note it is seen in patients with HIV. They recommend antiretroviral therapy and antibiotics for bacterial infections.

Incorrect Answers:
Answer B: Determining drug sensitivities against the patient’s pulmonary infection would be of low diagnostic utility since IRIS best explains his current clinical presentation.

Answer C: Discontinuing antimicrobial treatment would not be appropriate since the patient has findings concerning for tuberculosis (upper lobe lung infiltrate), and lack of treatment can lead to progression of his infection.

Answer D: Obtaining a D-dimer level is only indicated in low-risk patients for pulmonary embolism by Wells criteria.

Answer E: Starting high-dose glucocorticoid treatment and discontinuing antiretroviral therapy would not be appropriate since discontinuing his antiretroviral therapy would not control his HIV infection, which would place him at greater risk of acquiring opportunistic infections. Corticosteroid use is part of symptom management as it decreases the inflammatory response.

Bullet Summary:
Immune reconstitution inflammatory syndrome (IRIS) can result in worsening of infectious symptoms and is managed by continuing antiviral therapy with symptomatic treatment.


Question: A 55-year-old man presents to the emergency department with chest pain and shortness of breath. He has a medical history of hypertension, diabetes, and obesity. His temperature is 98.6°F (37.0°C), blood pressure is 177/118 mmHg, pulse is 127/min, respirations are 11/min, and oxygen saturation is 98% on room air. An ECG is performed and notable for ST elevation in leads II, III, and aVF. The patient is treated appropriately and transferred to the medical floor. On the 2nd day of his hospitalization, the patient has abdominal pain. His serum lipase is 272 U/L and his creatinine is 1.6 mg/dL. A physical exam is notable for the finding in Figure A. He is requesting pain medication for his abdominal pain. Which of the following is the most likely underlying diagnosis?

Answer: Cholesterol embolism

Explanation:
This patient is presenting with abdominal pain and livedo reticularis after a catheterization procedure. These symptoms are suggestive of a cholesterol embolism.

A cholesterol embolism typically presents after any vascular procedure due to a dislodged cholesterol emboli. Symptoms include livedo reticularis, gastrointestinal problems such as mesenteric ischemia or pancreatitis, and acute kidney injury. Patients who have undergone cardiac catheterization should be monitored for the development of this complication. Treatment is centered around treating the current complications, often using supportive therapy as they self-resolve. In addition, patients should be treated carefully to prevent recurrent embolism.

Maningding and Kermani review the evidence regarding the presentation of vasculitis mimics. They discuss how cholesterol embolism can cause diverse systemic symptoms and livedo reticularis. They recommend carefully considering the history of each patient.

Figure/Illustration A is a clinical photograph demonstrating a netlike reticular bluish discoloration of the skin (red circle). These findings are consistent with livedo reticularis.

Incorrect Answers:
Answer B: Heart failure and reinfarction could present with renal failure but would likely present with other symptoms of heart failure as well (pulmonary crackles, edema, and jugular venous distension). Treatment of a repeat infarct involves catheterization and fluid overload involves volume optimization.

Answer C: Medication side effects could explain this patient's livedo reticularis, but the drugs that may cause this (certain antivirals and amantadine) would not have been given to this patient. These medications also typically do not cause abdominal pain.

Answer D: Pancreatitis presents with abdominal pain and an elevated lipase; however, it is not the underlying pathology for this patient's presentation but rather is a complication of the cholesterol embolism. Treatment of pancreatitis is with gastrointestinal rest and fluid support.

Answer E: Renal failure is another complication in this patient secondary to the cholesterol embolism as revealed by the elevated creatinine, but is not the underlying pathology. Treatment is with renal replacement therapy if renal function does not return promptly.

Bullet Summary:
Cholesterol embolism presents after a vascular procedure with livedo reticularis, gastrointestinal complications, and acute kidney injury.


Question: A 32-year-old man presents to his primary care provider for a headache. He reports that he has headaches at night several times a week. He first developed these headaches over 1 year ago, but they started up again 3 weeks ago. The episodes start suddenly and feel like a stabbing, electrical pain over his left eye. He also reports tearing of the left eye during these episodes. The headaches self-resolve over the course of 2-3 hours, but the patient complains that he is avoiding going to sleep for fear of waking up in pain. His medical history includes type 1 diabetes mellitus and an episode of herpes zoster on his right flank 1 year ago. His only home medication is insulin. His temperature is 98.6°F (37°C), blood pressure is 112/69 mmHg, pulse is 61/min, and respirations are 14/min. On physical exam, his extraocular muscles are intact and his eyes are not injected. A CT of the head and sinuses shows no acute abnormalities. Which of the following is most likely to prevent future episodes of headache in this patient?

Answer: Verapamil

Explanation:
This patient presents with an episodic, stabbing pain in the periorbital region that occurs at night, which is consistent with a diagnosis of cluster headaches. Verapamil is used as prophylaxis against cluster headaches.

Cluster headaches usually occur at night and may wake patients out of sleep. Cluster headaches may occur several times a week to multiple times daily and the attacks may be followed by a period of remission. Cluster headaches also typically involve the periorbital region and are unilateral. Patients also classically describe their headaches as “stabbing”. Tension-type headaches are more commonly described as dull and migraines are usually described as pulsating or throbbing. Treatment is with high-flow oxygen during acute episodes and prophylaxis against long-term headaches includes calcium channel blockers such as verapamil.

Hoffman and May review the evidence regarding the treatment of cluster headaches. They discuss how high-flow oxygen and triptans are the most effective abortive treatment for acute attacks. They recommend using chronic prophylactic medications such as verapamil.

Incorrect Answers:
Answer A: Carbamazepine is the treatment of choice for trigeminal neuralgia, which presents as shooting pain in the face. They have exquisite tenderness to palpation over the affected neurologic distribution.

Answer B: High-flow oxygen is an abortive treatment for cluster headaches. Cluster headaches typically present in men with unilateral pain around the eye that is worse at night. Associated symptoms include spasms of the unilateral face as well as tearing and visual abnormalities in the eye. This treatment is not effective for long-term prophylaxis.

Answer C: Sumatriptan is used as an abortive treatment for cluster headaches and migraines, but it is not used as prophylaxis for either. Migraines present as unilateral, throbbing headaches that may be associated with nausea and/or vomiting, photophobia, phonophobia, and aura.

Answer D: Topiramate is used as prophylaxis for migraines rather than cluster headaches. Migraines present as unilateral, throbbing headaches that may be associated with nausea and/or vomiting, photophobia, phonophobia, and aura.

Bullet Summary:
Cluster headaches classically present as sharp or stabbing periorbital headaches that occur at night, with verapamil being the prophylactic treatment of choice and high-flow oxygen being the most effective abortive treatment.


Question: A 62-year-old man presents to the emergency department with skin lesions. He felt itchy recently, then noticed skin lesions that broke out prompting him to come to the emergency department. He recently went camping and hiking in the woods. The patient drinks 1-2 beers per day and smokes 1 pack of cigarettes per day. He is currently sexually active with multiple partners and does not use condoms. The patient was discharged 1 week ago for pneumonia which was treated with azithromycin; however, he feels that his symptoms may be returning. His temperature is 99.5°F (37.5°C), blood pressure is 157/78 mmHg, pulse is 90/min, respirations are 15/min, and oxygen saturation is 98% on room air. Physical exam reveals the findings in Figure A on the patient's arm. The skin lesions are thick and do not break when pressure is applied. Which of the following most appropriately describes the most likely diagnosis?

Answer: Linear IgG along the basement membrane

Explanation:
This patient is presenting with pruritic bullous skin lesions with a thick/tough covering suggesting a diagnosis of bullous pemphigoid. Linear IgG binding of anti-hemidesmosome antibodies along the basement membrane is the underlying cause of this disease.

Bullous pemphigoid presents with a urticarial prodrome in elderly patients followed by the formation of tense bullae that do not break when pressure is applied to them. IgG antibodies bind the hemidesmosome along the basement membrane and appear linear on immunofluorescence. Risk factors that are associated with this condition include the initiation of new medications such as loop diuretics, metformin, and neuroleptics. Steroids are the treatment of choice.

Miyamoto et al. review the evidence regarding the diagnosis and treatment of bullous pemphigoid. They discuss how high-potency corticosteroids are the mainstay of treatment for this disease. They recommend considering adjuvant therapy with doxycycline, dapsone, and immunosuppressants.

Figure/Illustration A is a clinical photograph showing bullous skin lesions (red circles). These lesions are tense and do not separate/break when pressure is applied to them and are classically seen in bullous pemphigoid.

Incorrect Answers:
Answer A: IgG in a fish-net pattern suggests a diagnosis of pemphigus vulgaris, which presents with skin lesions that are flaccid and break easily when pressure is applied. Treatment is with corticosteroids.

Answer C: Multi-nucleated giant cells suggests a diagnosis of HSV or herpes zoster virus, which presents with potentially painful vesicles distributed in a dermatomal pattern (for zoster). Treatment is with antivirals such as valacyclovir.

Answer D: Panniculitis suggests a diagnosis of erythema nodosum, which presents with painful, raised nodules that are associated with inflammatory disorders and infection. Treatment is centered on addressing the underlying pathology.

Answer E: Type IV hypersensitivity reaction suggests a diagnosis of contact dermatitis, which presents with pruritic lesions after exposure to a particular antigen such as poison ivy, poison oak, or nickel. Treatment is avoidance of the precipitating agent and steroids as well as symptomatic control.

Bullet Summary:
Bullous pemphigoid occurs secondary to anti-hemidesmosome antibodies which appear linear along the basement membrane on immunofluorescence.


Question: A 45-year-old man presents to his primary care physician with a rash. He first noticed the rash 2 weeks prior and he endorses intermittent itchiness from the rash. His medical history is significant for chronic hepatitis C infection, hypertension, type 2 diabetes mellitus, and heart failure. The patient works as a butcher at a local meat processing shop and is sexually active with several partners. He does not use barrier protection. His temperature is 98.6°F (37.0°C), pulse is 90/min, blood pressure is 155/95 mmHg, and respirations are 12/min. On physical exam, his skin has the finding shown in Figure A. Fine, lace-like white lines are also noted on the patient’s buccal mucosa. Which of the following is the most likely diagnosis?

Answer: Lichen planus

Explanation:
This patient presents with several purple, polygonal, pruritic papules and plaques. These findings are most consistent with a diagnosis of lichen planus.

Lichen planus is an inflammatory skin disorder most commonly characterized by an eruption of Purple, Polygonal, Planar, Pruritic, Papules and Plaques (the 6 P’s), often on extensor surfaces such as the wrist. Development of fine white lines on the surfaces of skin lesions, as well as on the buccal mucosa (Wickham striae), are also characteristically seen in this disease. Concurrent hepatitis C infection is a risk factor for lichen planus. A skin biopsy will show a sawtooth infiltrate of lymphocytes at the dermal-epidermal junction. Treatment is with antihistamines for pruritus and topical steroids for localized disease as well as addressing the underlying cause.

Tziotzios et al. review the evidence regarding the diagnosis and treatment of lichen planus. They discuss how the molecular basis of this disorder is relatively unknown. They recommend making a clear diagnosis to allow for treatment.

Figure/Illustration A shows multiple purple, polygonal, papules and plaques on the wrist (red circles). These findings are characteristic of lichen planus.

Incorrect Answers:
Answer A: Atopic dermatitis most commonly presents with pruritic, lichenified plaques on the flexural surfaces. The mucous membranes are not involved. Treatment is with topical moisturizers and antihistamines for pruritus. This disease is also associated with other atopic conditions such as asthma and seasonal allergies.

Answer C: Prurigo nodularis is characterized by hypertrophic, dome-shaped papules that develop secondary to chronic scratching. The mucous membranes are not involved. Treatment is with avoidance of the triggering behavior such as scratching and antihistamines for pruritus.

Answer D: Psoriasis is characterized by silver, scaly plaques that bleed easily when the scale is physically removed (Auspitz sign). Patients with cutaneous psoriasis are at increased risk for the development of psoriatic arthritis. Psoriasis can be treated with topical corticosteroids as well as calcipotriene.

Answer E: Scabies is a cutaneous infection with the mite Sarcoptes scabei that presents with severe pruritus, especially in the intertriginous areas. Patients may have serpiginous scaling lesions that represent the burrowing of the mite through the skin, but mucous membrane lesions are absent. Treatment can include topical permethrin first line.

Bullet Summary:
Lichen planus presents with the 6 P’s – Purple, Pruritic, Polygonal, Planar, Papules and Plaques.


Question:
A 27-year-old woman presents to her primary care physician with new hair growth on her face and lower abdomen over the last month. She has started to develop pimples on her face and back over the last several months. Her last menstrual period was over 3 months ago and her periods have been irregular over the last year. She has been gaining weight recently. The patient has a medical history of obesity and prediabetes with a hemoglobin A1c of 6.0% last year. Her temperature is 98.5°F (36.9°C), pulse is 80/min, blood pressure is 139/88 mmHg, and respirations are 13/min. Cardiopulmonary exam is unremarkable, and the patient’s abdomen appears slightly distended but exhibits no tenderness to palpation. The patient’s face has coarse stubble along the jawline and on the upper lip, and there is similar hair along the midline of her lower abdomen. A pelvic exam reveals mild clitoromegaly, a normal anteverted uterus, and a large left adnexal mass that is mildly tender. Her laboratory test results are shown below:

Hemoglobin: 13.9 g/dL
Leukocyte count: 8,000 cells/mm^3
Platelet count: 142,000/mm^3

DHEAS: 73 ug/dL (Normal: 145-395 ug/dL)
Testosterone: 256 ng/dL
17-hydroxyprogesterone: 214 ng/dL (Normal: < 200 ng/dL)

Ultrasound findings are shown in Figure A. Which of the following is the most likely diagnosis in this patient?

Answer: Ovarian tumor

Explanation:
This young woman presents with rapid virilization, elevated testosterone, and a large left adnexal mass that is primarily solid on ultrasound. These findings are most consistent with an ovarian androgen-secreting tumor.

Sertoli-Leydig cell tumors are the most common androgen-secreting tumor of the ovaries and classically result in rapid virilization of affected women. Testosterone levels are often over 200 ng/dL, and 17-hydroxyprogesterone may also be slightly elevated as it is an androgen precursor. The androgen excess may result in symptoms such as facial and abdominal hirsutism, oligomenorrhea, deepening voice, and acne. Treatment involves staging the tumor and surgical resection of the tumor if possible.

Durmus et al. review the evidence regarding the diagnosis and treatment of Sertoli-Leydig cell tumors. They discuss how this tumor generally has a favorable prognosis compared to malignant epithelial tumors. They recommend using fertility-preserving surgeries in younger patients.

Figure/Illustration A shows an ultrasound of the left ovary, which has a predominantly solid mass with vascularity and some cystic spaces (red circle). These findings are consistent with an ovarian tumor.

Incorrect Answers:
Answer A: Adrenal tumors may secrete androgens and cause similar symptoms of virilization, but the presence of a malignant-appearing ovarian mass in this patient is more consistent with ovarian pathology. Furthermore, adrenal tumors typically secrete DHEAS, which can be a helpful test for localizing the source of androgen excess. Treatment is with surgical excision.

Answer B: Congenital adrenal hyperplasia (CAH) results from one of several possible enzyme deficiencies in the steroid pathway and may appear later in life as virilization of a woman. While 17-hydroxyprogesterone elevation is a strong indicator of the most common subtype of CAH, this patient’s ultrasound findings suggest ovarian pathology instead, which could also elevate this androgen precursor. Treatment is with hormone replacement therapy.

Answer C: Ovarian hyperthecosis is hyperplasia of the theca interna of the ovary, which produces androgens. Testosterone levels would be elevated and virilization may occur, but ultrasound findings would show a bilateral increase in stromal tissue as opposed to a unilateral solid mass. Treatment is with hormonal therapy.

Answer E: Polycystic ovary syndrome (PCOS) can also cause elevated testosterone, though levels are typically lower than 100 ng/dL. Frank virilization with clitoromegaly and voice deepening would not be expected with PCOS, nor would an ovarian mass. Treatment is with metformin and lifestyle modifications.

Bullet Summary:
Sertoli-Leydig cell tumors of the ovary can produce androgens and result in rapid onset of virilization with elevated testosterone levels and an adnexal mass on ultrasound.


Question: A study is performed that looks at individuals who suffer from opioid use disorder and the effect the disorder has on their daily life and functionality. Individuals are surveyed using a validated method and followed up in 6-month intervals for 5 years. At the end of the study period, 40% of individuals have replied to the survey throughout the entire period. Analyzing only those subjects who responded throughout the entire period, it is determined that opioid use disorder only minimally impairs individuals in their daily functioning. Which of the following most likely occurred in this study?

Answer: Attrition bias

Explanation:
This study following individuals who abuse opioids with a 40% follow-up response rate suggests that opioid use disorder (known for impairing daily functioning) has only a minor effect on patient functionality. This is most likely secondary to attrition bias, or a loss to follow-up of participants in a non-random fashion whereby more severe cases stopped responding and were thus left out.

Bias in studies distorts outcomes and can make interpreting results challenging. For this reason, it is important to be meticulous when designing a study with every effort to minimize bias. The attrition bias can occur when individuals are lost to follow-up in a non-random fashion. For example, consider the assessment of daily functionality via a validated method in individuals with coronary artery disease. Those who are severely impaired from disease progression may not follow up in this study, thus altering results and removing more severe cases from the analysis. Having a higher response rate can help mitigate this bias, but is more costly as it may be difficult to ensure that every participant follows up.

Nunan et al. discuss the attrition bias. They note how it can affect studies and the data collected. They recommend mitigating the attrition bias for more accurate results and clinical application.

Incorrect Answers:
Answer B: Confounding variables are variables that are correlated with the studied variable that better explain the difference between 2 groups. For example, it may be found that alcohol is associated with lung cancer when in reality, the confounding variable of smoking (more common in individuals who drink alcohol) explains this difference.

Answer C: Late-look bias occurs when patients with severe disease are not studied because they are dead, critically ill, or unavailable to be studied, making the disease overall appear less severe. For example, patients with HIV may not have increased morbidity and mortality in a study. However, this may be a result of all the critically ill cases being too sick or dead and thus unable to participate thus distorting the outcome.

Answer D: Recall bias occurs when individuals with disease or an adverse outcome are more likely to recall an exposure given the occurred outcome, skewing their memory and thus the results. For example, pregnant mothers who have a newborn with a defect or condition may be more likely to recall certain exposures (such as exposure to pollution).

Answer E: Volunteer bias occurs when people who volunteer for a study are fundamentally different from the general population or those who do not volunteer. An example may be individuals volunteering in a study involving exercise as those who are interested in participating in an exercise study may be more motivated or healthier at baseline.

Bullet Summary:
Attrition bias occurs when individuals are lost to follow-up in a non-random fashion leading to skewed results.


Question: A 62-year-old woman is brought to a physician by her husband for fluctuating changes in behavior and hallucinations over the past 2 years. On occasion, she becomes difficult to understand and her speech becomes disorganized. She also frequently sees "small people" and animals on the dining room table, which is disturbing to her. Her medical problems include hypertension and chronic obstructive pulmonary disease for which she takes amlodipine, albuterol, ipratropium, and a fluticasone inhaler. She was formerly an executive at a software company but had to retire due to frequent memory lapses. Her temperature is 98.6°F (37°C), blood pressure is 120/80 mmHg, pulse is 80/min, and respirations are 12/min. Physical exam is notable for slowed movements and difficulty with balance at rest, which were not present at her wellness visit 1 year ago. Which of the following pathological findings (Figures A-E) would most likely be seen if a brain biopsy were performed?

Answer: Figure C

Explanation:
This patient with fluctuating changes in behavior and cognition, visual hallucinations, memory loss, and extrapyramidal symptoms (bradykinesia, postural instability) most likely has Lewy body dementia. Lewy body dementia is characterized histologically by Lewy bodies, which are intracytoplasmic eosinophilic inclusions of alpha-synuclein (shown in Figure C).

Alpha-synuclein is normally abundantly present in its unfolded form in neurons. Abnormal folding of alpha-synuclein leads to aggregation into insoluble fibrils. These intracytoplasmic aggregates (Lewy bodies) are seen in Parkinson disease, Lewy body dementia, and multiple system atrophy, which are collectively referred to as alpha-synucleinopathies. Lewy body dementia is the second most common degenerative dementia and presents with fluctuating cognition, visual hallucinations, parkinsonism (bradykinesia, postural instability, rigidity, and a resting tremor), rapid eye movement (REM) sleep disorder, autonomic dysfunction, and sensitivity to antipsychotics. Lewy body dementia can be distinguished from Parkinson disease with dementia by the timing of symptoms. In Lewy body dementia, cognitive symptoms begin at the same time as or 1 year prior to the onset of movement symptoms whereas in Parkinson disease the cognitive symptoms classically occur over 1 year after motor symptoms. There is no cure for Lewy body dementia, and treatment is aimed at alleviating symptoms.

Arnaoutoglou et al. reviewed the epidemiology, pathology, treatment, and future directions for research of Lewy body dementia. The authors found potential genetic bases for Lewy body dementia, including mutations in the GBA gene. They recommended that further research be conducted on the therapeutic implications of these genetic findings.

Figure/Illustration A shows a hematoxylin and eosin (H&E) stained brain biopsy of a patient with Creutzfeldt-Jakob disease. Characteristic spongiform changes in neurons (yellow boxes) and agglomerated prions (orange arrows) are seen in this slide.

Figure/Illustration B shows an H&E stained brain biopsy of a patient with a small lacunar infarct on low magnification. A central area of tissue loss (yellow outline) and surrounding residual gliosis (orange arrows) are seen in this slide.

Figure/Illustration C shows a brain biopsy of a patient with Lewy body dementia stained with mouse anti-alpha-synuclein antibody and counterstained with hematoxylin. Lewy bodies (intracytoplasmic eosinophilic inclusions of alpha-synuclein) are indicated by orange arrows. Note that Lewy bodies are always found intracellularly (neurons highlighted by blue boxes).

Figure/Illustration D shows an H&E stained brain biopsy of a patient with Alzheimer disease. Extracellular neurofibrillary tangles found in Alzheimer disease are indicated by black arrows.

Figure/Illustration E shows an H&E stained brain biopsy of a patient with frontotemporal dementia. A characteristic Pick cell (red box), or ballooned neuron, with dissolved chromatin (yellow arrow), is seen in this slide.

Incorrect Answers:
Answer A: Figure A shows an H&E stained brain biopsy of a patient with Creutzfeldt-Jakob disease. Creutzfeldt-Jakob disease is a rapidly progressive dementia that manifests with poor concentration, declining executive function, startle myoclonus, 14-3-3 protein on lumbar puncture, and synchronous sharp wave complexes on electroencephalogram (EEG). Clinical decline occurs over the course of weeks and months, culminating in death within a year. Creutzfeldt-Jakob disease shows spongiform vacuolation due to the accumulation of abnormal prion protein (PrPsc).

Answer B: Figure B shows an H&E stained brain biopsy of a patient with a small lacunar infarct. Lacunar infarcts may be asymptomatic or cause focal neurologic deficits such as motor hemiparesis, pure sensory stroke, ataxic hemiparesis, or dysarthria-clumsy hand syndrome depending on the territory involved. Lacunar strokes will show diffuse eosinophilia of the affected area, followed by liquefactive necrosis with neutrophilic infiltration, followed by macrophages with surrounding reactive gliosis, finally leading to an area of tissue loss with residual gliosis.

Answer D: Figure D shows an H&E stained brain biopsy of a patient with Alzheimer disease. Alzheimer disease presents with a gradual cognitive decline with difficulty completing activities of daily living. Memory is the most prominently affected domain. Visual hallucinations, fluctuating levels of cognition, and extrapyramidal symptoms are not common in Alzheimer disease. Amyloid plaques and neurofibrillary tangles may be seen on brain biopsy.

Answer E: Figure E shows an H&E stained brain biopsy of a patient with frontotemporal dementia (Pick disease). The behavioral variant of frontotemporal dementia is associated with early-onset personality and behavioral changes, and it may be associated with extrapyramidal symptoms. Unlike Lewy body dementia, memory is usually not affected in frontotemporal dementia until late in the disease course. frontotemporal dementia is characterized by Pick cells (ballooned neurons with dissolved chromatin) and Pick bodies, round intracellular aggregates of hyperphosphorylated tau protein.

Bullet Summary:
Lewy body dementia presents with alterations in consciousness, disorganized speech, visual hallucinations, extrapyramidal symptoms, early compromise of executive functions, and eosinophilic intracytoplasmic inclusions of alpha-synuclein (Lewy bodies) on biopsy.


Question: A 6-month-old boy is brought to the physician by his mother for abnormal movements. Several times a day, he experiences paroxysmal episodes of crying, bending at the waist, and jerking of the arms and legs. These episodes last 1-2 seconds, but occur in clusters every 20-30 seconds for several minutes. His mother's pregnancy, labor, delivery, and his neonatal course have been unremarkable. He is rolling over less frequently than before, has worse head control, and no longer smiles socially. His temperature is 98.6°F (37°C), blood pressure is 92/46 mmHg, pulse is 115/min, and respirations are 34/min. On examination, no dysmorphic features are noted. A 24-hour electroencephalography (EEG) is performed, during which the patient has one of these spells. A chaotic pattern of slowing and multifocal epileptiform charges is seen. Which of the following is the pathophysiology of this patient's condition?

Decreased gamma aminobutyric acid (GABA) levels

Excess of corticotropin releasing hormone

Answer: Excess of corticotropin releasing hormone

Explanation:
This patient with infantile spasms (bending at the waist and jerking out the arms and legs), developmental regression (rolling over less frequently, worsening head control, loss of social smile), and hypsarrhythmia on video-EEG (slowing and multifocal epileptiform discharges) are characteristic of West syndrome. West syndrome is caused in part by an excess of corticotropin-releasing hormone which leads to increased neuronal excitability.

The pathogenesis of West syndrome is incompletely understood. Infantile spasms are often idiopathic, but may also be secondary to tuberous sclerosis, hypoxic-ischemic encephalopathy, congenital brain malformations, aminoacidopathies, and organic acidopathies. Brain insults may activate a neuroendocrine stress response, which in turn leads to abnormalities of the hypothalamic-pituitary-adrenal axis. Disturbed immune activation may also play a role. Patients will present with infantile spasms, developmental regression, and slowing and multifocal epileptiform discharges known as hypsarrhythmia. Many affected infants are responsive to ACTH therapy, with cessation of spasms and resolution of hypsarrhythmia in many cases.

D’Alonzo et al. review the epidemiology, clinical presentation, pathophysiology, and treatment of West syndrome. They discuss how patients will present with the classic symptoms of spasms and regression. They recommend early diagnosis of this syndrome so that patients can be treated appropriately.

Incorrect Answers:
Answer B: Abnormalities in T-type calcium channels may contribute to absence seizures. Absence seizures are generalized seizures that involve brief, sudden lapses of consciousness and are more common in children. This child’s developmental regression, infantile spasms, and EEG findings are more consistent with West syndrome.

Answer C: Anti-N-methyl-D-aspartate (NMDA) receptor antibodies may cause anti-NMDA encephalitis. Anti-NMDA encephalitis presents with seizures, psychiatric manifestations, and decreased level of consciousness. Hypsarrhythmia is characteristic of West syndrome and is not consistent with anti-NMDA encephalitis.

Answer D: Decreased gamma-aminobutyric acid (GABA) levels were once theorized to be the basis of epilepsy syndromes. This theory is less accepted today. Moreover, West syndrome is likely not mediated by disturbances in GABA. Nonetheless, vigabatrin, which in part works by inhibiting GABA metabolism, is an effective medication for patients with West syndrome.

Answer E: Vitamin B6 deficiency has not been documented in West syndrome. Some studies have suggested vitamin B6 may be of some benefit in the treatment of infantile spasms; however, there is no evidence that response rates to B6 are different from the spontaneous remission rates predicted from natural history data. Therefore, the pathophysiology of West syndrome is more likely CRH-excess mediated rather than due to a deficiency of vitamin B6.

Bullet Summary:
West syndrome, which may be caused by CRH excess, presents with hypsarrhythmia, developmental regression, and infantile spasms.


Question: A 23-year-old woman is admitted to the inpatient psychiatry unit after her boyfriend reported she was “acting funny and refusing to talk.” The patient’s boyfriend states that he came home from work and found the patient sitting up in bed staring at the wall. When he said her name or waved his hand in front of her, she did not respond. When he tried to move her, she would remain in whatever position she was placed. Her temperature is 99°F (37.2°C), blood pressure is 122/79 mmHg, pulse is 68/min, and respirations are 12/min with an oxygen saturation of 98% on room air. The patient is lying on the bed with her left arm raised and pointing at the ceiling. She resists any attempt to change her position. The patient remains mute and ignores any external stimuli. The patient’s medical history is significant for depression. She was recently switched from phenelzine to fluoxetine. Which of the following is the most appropriate initial therapy?

Answer: Lorazepam

Explanation:
The patient has a history of depression and is presenting with decreased motor activity, waxy flexibility, lack of response to external stimuli, and mutism, suggesting the diagnosis of catatonia. Catatonia should initially be treated with benzodiazepines like lorazepam.

Catatonia is a state of psychomotor immobility and apathy that is associated with a mood disorder or psychosis. The diagnosis is made clinically by having at least 3 of the following symptoms: stupor (no psychomotor activity), negativism (no response to external stimuli), catalepsy (muscle rigidity in a position against gravity), waxy flexibility (maintaining positioning placed by the examiner), mutism, echolalia (mimicking speech), echopraxia (mimicking movements), stereotypy, grimacing, and non-purposeful agitation or mannerisms. Initial treatment involves benzodiazepines for symptomatic relief. If the patient is unresponsive to benzodiazepines, electroconvulsive therapy (ECT) can be used.

Francis reviews the evidence regarding the treatment of patients with catatonia. He discusses how benzodiazepines can be used with rapid improvement in symptoms. He recommends electroconvulsive therapy in refractory cases.

Incorrect Answers:
Answer A: Benztropine and IV diphenhydramine can be used to treat an acute dystonic reaction. Dystonic reactions present as involuntary spasms or sustained contractions of the face, neck, torso, pelvis, extremities, and larynx. Medications that block dopamine D2 receptors, such as neuroleptics and antiemetics, carry the greatest risk.

Answer B: Cyproheptadine is a serotonin antagonist that may be part of the treatment for serotonin syndrome. Serotonin syndrome may occur as a result of the simultaneous use of monoamine oxidase inhibitors (MAOIs), selective serotonin reuptake inhibitors (SSRIs), or serotonin-norepinephrine reuptake inhibitors (SNRIs). It presents with myoclonus, hyperthermia, flushing, tachycardia, and delirium.

Answer C: Electroconvulsive therapy is an effective treatment for catatonia but would be considered 2nd line to benzodiazepines for refractory cases.

Answer D: Haloperidol is an antipsychotic, which may worsen catatonia. It can cause neuroleptic malignant syndrome, which can mimic catatonia.

Bullet Summary:
Catatonia can present in patients with a history of mood disorders and psychosis with symptoms of decreased motor activity, rigid posture, and mutism, and should be treated initially with a benzodiazepine.


Question: A 30-year-old man presents to the emergency room with a laceration over the 4th metacarpophalangeal (MCP) joint of his right hand. He reports that he is a mailman, and his closed fist was bitten by a dog while he was delivering mail yesterday. He reports pain but denies fevers, chills, drainage, or any other symptoms. The dog is up to date on vaccinations. His last tetanus vaccine was 3 years ago. He has no medical history and takes no medications. His temperature is 98.6°F (37.0°C), pulse is 80/min, blood pressure is 125/75 mmHg, and respirations are 16/min. Examination of the patient's right hand is shown in Figure A. Which of the following is the most appropriate next step in management?

Answer: Amoxicillin-clavulanate

Explanation:
This patient has suffered a clenched fist injury which are generally managed with irrigation and amoxicillin-clavulanate.

Amoxicillin-clavulanate is the usual first-line antibiotic for patients with a human or dog bite. Lacerations sustained from animal or human bites should not be sutured due to the risk of infection. Amoxicillin-clavulanate is first-line therapy for prophylaxis and treatment of human bites and dog bites, in general. Closed fist injuries put the patient at a high risk for osteomyelitis, septic arthritis, and tenosynovitis; therefore, prophylactic antibiotics are appropriate. Amoxicillin-clavulanate provides essential coverage against Pasturella multocida, commonly found in the mouths of dogs, cats, and other mammals. In patients with a penicillin allergy, agents such as TMP-SMX, doxycycline, or cefdinir paired with anaerobic coverage (clindamycin or metronidazole) is appropriate.

Presutti discusses the prevention and treatment of dog bites. Appropriate treatment consists of immediate, copious irrigation, assessment for risk of tetanus and rabies, and administration of prophylactic antibiotics as discussed above.

Figure A shows a dog bite wound over the 4th MCP of the right hand.

Incorrect Answers:
Answer B: Cephalexin does not cover species that are typically present in the mouths of dogs and other mammals and is therefore not an appropriate antibiotic choice for this patient as monotherapy.

Answer C: Clindamycin provides coverage of anaerobic species, but is not sufficient alone for treatment of this patient's injury.

Answer D: Clindamycin plus doxycycline may be appropriate coverage for a dog bite in a patient with an allergy to amoxicillin-clavulanate. However, this patient has no stated allergies and should receive amoxicillin-clavulanate.

Answer E: Wound closure and amoxicillin-clavulanate would not be appropriate. Lacerations sustained from dog or cat bites are not sutured closed due to the risk of infection.

Bullet Summary:
Amoxicillin-clavulanate is the first line antibiotic choice for patients with dog or cat bites.


Question: A 59-year-old woman presents to her primary care physician for trouble sleeping. When she goes to bed at night, she has an urge to get up out of bed and walk around. The patient often wakes her husband when she does this which irritates him. There is a perpetual uneasiness and feeling of a need to move at night which is relieved by getting up and walking around. The patient denies symptoms during the day. She works as a mail carrier and is nearing retirement. She has a medical history of anxiety, depression, irritable bowel syndrome, and dysmenorrhea. She is not currently taking any medications. Her temperature is 99.5°F (37.5°C), blood pressure is 157/98 mmHg, pulse is 80/min, respirations are 17/min, and oxygen saturation is 98% on room air. Physical exam reveals 5/5 strength in the upper and lower extremities, 2+ reflexes in the upper and lower extremities, a stable gait pattern, and normal sensation. Cardiopulmonary and abdominal exams are within normal limits. Which of the following is the most appropriate initial step in management?

Answer: Iron studies

Explanation:
This patient is presenting with the need to get up and walk around at night, which is suggestive of restless leg syndrome. The most appropriate initial step in management is collecting iron studies to assess for iron deficiency.

Restless leg syndrome presents with a sustained sense of restlessness and a feeling of a need to move one's legs. Symptoms typically occur at night and are relieved by activities such as walking. Iron deficiency can be a precipitating factor in restless leg syndrome as iron is a cofactor in the production of dopamine. Prior to administering iron, it is important to first confirm or rule out the diagnosis of iron deficiency with laboratory values which should include a CBC and iron studies. If iron deficiency exists, iron should be administered. If iron deficiency is not present, then dopamine agonists such as pramipexole or ropinirole can be administered.

Gossard et al. review the evidence regarding the diagnosis and treatment of restless leg syndrome. They discuss how iron deficiency is associated with the development of this disorder. They recommend iron repletion in deficient patients.

Incorrect Answers:
Answer A: Alprazolam could be an appropriate step in management if the patient suffers from episodic panic attacks/anxiety. It is not an optimal long-term therapy for anxiety or depression. Benzodiazepines are not first-line in treating restless leg syndrome.

Answer B: Ferrous sulfate would not be indicated until iron deficiency is confirmed. Iron deficiency is associated with restless leg syndrome as iron is a cofactor in the production of dopamine.

Answer D: Pramipexole is a dopamine agonist that is an effective therapy for restless leg syndrome. However, it is more important to treat any underlying causes for restless leg syndrome such as iron deficiency prior to starting a dopamine agonist.

Answer E: Supportive therapy and an exercise routine ignore the potential underlying pathology and do not offer any specific treatment for this patient's restless leg syndrome. Exercise can improve symptoms of restless leg syndrome but iron deficiency must still be ruled out.

Bullet Summary:
Patients with restless leg syndrome should be assessed for iron deficiency and treated if they are iron deficient.


Question: A 35-year-old man presents to the emergency department with altered mental status. He was found by his roommate to be disoriented this morning. He had complained of a right-sided headache for the past 5 days. He has a history of human immunodeficiency virus (HIV) infection being treated with bictegravir, emtricitabine, and tenofovir. His last CD4 cell count was 500/mm^3. He does not smoke tobacco and drinks alcohol socially. His temperature is 104.2°F (40.1°C), blood pressure is 110/70 mmHg, pulse is 110/min, and respirations are 22/min. Examination reveals 3/5 strength to right shoulder abduction and elbow flexion/extension and 4/5 strength to right hip flexion/extension. The remainder of the strength exam on the right and left sides is normal. Neck flexion does not elicit pain, and there are no tongue lacerations. During the exam, the patient’s eyes are seen to roll backward with repeated flexion/extension of his extremities and loss of urine. This stops after 1 minute. Which of the following is the most likely diagnosis?

Answer: Brain abscess

Explanation:
This HIV-positive patient presents with fever, unilateral headache, altered mental status, focal neurological deficits (3/5 strength to right shoulder abduction, elbow flexion/extension, hip flexion/extension), and a generalized tonic-clonic seizure, suggestive of a brain abscess.

A brain abscess typically presents in patients with underlying risk factors for infection, such as positive HIV status or bacterial endocarditis with hematogenous bacterial seeding. Patients present with fever, unilateral headache, altered mental status, focal neurological deficits, and fevers. Work-up consists of blood cultures, CT scan, and confirmatory magnetic resonance imaging with gadolinium contrast, showing a focal, hyperintense lesion with restricted diffusion. Treatment is with empiric broad-spectrum antibiotic therapy (e.g., vancomycin, metronidazole, and cefepime for gram-positive, gram-negative, and Pseudomonas coverage in immunocompromised patients) and surgical drainage.

Brouwer et al. review the causes, diagnosis, and treatment of brain abscesses. They discuss the importance of rapid initiation of antimicrobial therapy in these patients.

Incorrect Answers:
Answers 1 & 5: Bacterial or fungal meningitis can present with fever, headache, focal neurological deficits, and seizures but patients typically have meningeal signs such as pain with neck flexion. Cryptococcal meningitis is commonly seen in HIV-positive patients with CD4 counts < 100/mm^3.

Answer C: Cytomegalovirus encephalitis can present with fever, altered mental status, headache, and focal neurological deficits in patients with HIV infection. It typically presents in patients with severe immunodeficiency, often with CD4 cell count < 50/mm^3. This patient’s CD4 cell count is 500/mm^3, making this less likely than an abscess.

Answer D: Epilepsy is a primary neurological disorder that can cause generalized tonic-clonic seizures but would not explain this patient’s fever or unilateral headache. While Todd paralysis (focal weakness after a seizure) can occur after seizures, this patient’s focal weakness predates his seizure. A primary seizure disorder is not diagnosed when seizures occur secondary to another process.

Bullet Summary:
Brain abscess presents with fever, altered mental status, unilateral headache, seizures, and focal neurological deficits in patients with risk factors for infection (for example HIV, bacterial endocarditis).


Question: A 24-year-old man with epilepsy refractory to valproic acid, phenytoin, and levetiracetam undergoes magnetic resonance imaging of his brain while monitored by anesthetic care. He wakes up screaming in pain due to an electrocardiogram lead having caused a significant thermal burn circumferentially around his left leg. He is admitted to the medical intensive care unit for continuous electroencephalogram monitoring while on a midazolam infusion for seizure suppression and supportive care for his burn. Overnight, the nurse continued to increase the patient's midazolam infusion rate, but she also noticed that his left toes were cold to the touch with significant edema. His temperature is now 100°F (37.8°C), blood pressure is 110/75 mmHg, pulse is 80/min, respirations are 10/min and oxygen saturation is 95% on 2 liters nasal cannula. No dorsalis pedis or posterior tibial pulses are detected on the left lower extremity. A delta pressure of 25 mmHg is obtained in the left leg. What is the most appropriate next step in management?

Intravenous fluid infusion based on Parkland formula

Answer: Escharotomy

Explanation:
This patient with a circumferential burn due to an ECG cable wrapped around his leg in an MRI machine now has clear evidence of compartment syndrome due to the eschar. The most appropriate next step in management is emergent escharotomy to restore blood flow.

Burns can be caused by chemical, thermal, electrical, and radiation sources. The initial inflammation causes vasodilatation and hyperemia, which can progress to edema and local microvascular thrombosis. If not promptly addressed, tissue necrosis and irreversible damage can occur. Circumferential burns can evolve into eschars that constrict blood flow and cause distal compartment syndrome. A delta pressure (diastolic pressure minus local compartment pressure) lower than 30 mmHg is diagnostic. In the case of eschar-induced compartment syndrome, the most appropriate next step is escharotomy to alleviate pressure.

Ormiston and Marappa-Ganeshan review the evidence regarding the diagnosis and treatment of patients with compartment syndrome. They discuss how this condition can be caused by many different pathologies including burns. They recommend the emergent release of constrictive structures.

Incorrect Answers:
Answer A: Amputation may be necessary if the distal limb is completely necrotic and not salvageable. Timely release of the eschar can allow for reperfusion of the limb and prevent this outcome.

Answer C: Fasciotomy is the treatment of choice for compartment syndrome not due to a circumferential eschar, but in this case the least invasive surgical intervention should be performed first without releasing all the compartments of the lower leg. If escharotomy does not relieve the compartment syndrome then fasciotomy may be required.

Answer D: Intravenous fluid infusion based on the Parkland formula is part of comprehensive burn management, but would not address the underlying compartment syndrome, which is more urgent at this time.

Answer E: Transfer to a specialized burn center can be considered since circumferential burns are one of the admission criteria, but early escharotomy should be performed first.

Bullet Summary:
Circumferential burns that cause eschars and compartment syndrome require an escharotomy.


Question: A 27-year-old woman presents for her first prenatal visit at an estimated gestational age of 16 weeks and 4 days by last menstrual period. She is presenting late to prenatal care due to significant anxiety about her pregnancy, as she and her husband had struggled with infertility for several years prior to conceiving. She has had nausea and vomiting for about 2 months, tender and swollen breasts, and cravings for foods she typically does not eat. She took a pregnancy test about 10 weeks ago and was too nervous to read the result immediately. After 24 hours, she saw that it was positive. The patient has a past medical history of bulimia nervosa but has not been symptomatic in 2 years. She also had an appendectomy at age 15 for appendicitis. She is a Ph.D. student and her husband is a physician. Her temperature is 98.5°F (36.9°C), pulse is 75/min, blood pressure is 122/76 mmHg, and respirations are 13/min. The patient’s affect is normal and she is pleasant and excited about her pregnancy. A physical exam is notable for abdominal distension but is otherwise unremarkable. Ultrasound is shown in Figure A, and urine human chorionic gonadotropin is negative in the office. Which of the following is the most likely diagnosis?

Answer: Pseudocyesis

Explanation:
This patient presents with signs and symptoms of pregnancy but a nongravid uterus on ultrasound and a negative pregnancy test. The most likely diagnosis is pseudocyesis.

Pseudocyesis, or false pregnancy, most commonly presents with abdominal distension, breast tenderness, nausea, and other typical symptoms of pregnancy. Patients truly believe they are pregnant and may report positive pregnancy tests at home (perhaps due to false positives from waiting too long before reading the result) but office testing is negative. Ultrasound will be normal and show the absence of a developing fetus. The mainstay of treatment is explaining the diagnosis in a therapeutic manner and offering counseling to help patients cope.

Small reviews the evidence regarding the diagnosis and treatment of pseudocyesis. He discusses how this disease is a heterogenous entity involving neuroendocrine changes. He recommends clearly defining the cause of this disease in patients.

Figure/Illustration A shows a transabdominal ultrasound with an empty cavity without signs of pregnancy (red circle). These findings are consistent with pseudocyesis.

Incorrect Answers:
Answer A: Couvade syndrome refers to a “sympathetic pregnancy,” in which a patient experiences pregnancy symptoms when someone close to her is pregnant. This does not apply to this patient because she believes that she is pregnant herself.

Answer B: Delusion of pregnancy is a false and fixed belief about being pregnant, despite factual evidence to suggest otherwise. Patients typically do not experience actual pregnancy symptoms and may have a history of psychotic disorders, both of which are inconsistent with this patient’s presentation. Treatment is with cognitive behavioral therapy.

Answer C: Feigned pregnancy is the intentional falsifying of symptoms for a clear external motive and is a subtype of factitious disorder or malingering. This patient does not express any desire for secondary gain and seems to truly believe that she is pregnant, which is more consistent with pseudocyesis.

Answer E: A recent miscarriage is unlikely, as urine hCG testing often takes up to a month to become negative after pregnancy loss. Furthermore, the patient reports that her symptoms have been consistently present, whereas a miscarriage would typically cause a cessation of pregnancy symptoms.

Bullet Summary:
Pseudocyesis is a somatic symptom disorder in which women believe they are pregnant and experience pregnancy symptoms without an actual pregnancy.


Question: A 42-year-old man presents to the urgent care clinic with low back pain. He was working on a home improvement project the day prior to presentation when the pain started. He describes the pain as "achy and sore." It is not positional and does not radiate. He denies fevers, chills, paresthesias, and bowel or bladder incontinence. He has a history of a distal radius fracture 2 years ago from falling off a ladder. He drinks 3 alcoholic beverages weekly and denies illicit drug use. The patient’s temperature is 98.4°F (36.9°C), blood pressure is 124/80 mmHg, pulse is 90/min, and respirations are 16/min. His body mass index (BMI) is 22.4 kg/m^2. There is tenderness to palpation of his paravertebral lumbar region bilaterally. Perineal and dermatomal sensation is symmetric and intact. Strength is 5/5 to knee flexion/extension and ankle dorsiflexion/plantarflexion. Patellar and Achilles reflexes are 2+ bilaterally. Raising either leg while the patient is in the supine position does not elicit any pain. Which of the following is the most likely diagnosis?

Answer: Lumbar strain

Explanation:
This patient presents with low back pain after activity with paravertebral tenderness and without red flag signs/symptoms, such as history of trauma or malignancy, intravenous drug use, saddle anesthesia (reduced perineal sensation), or neurological deficits. The most likely diagnosis is a lumbar strain.

The differential diagnosis of low back pain is broad and includes mechanical causes such as lumbar strain, osteoarthritis, spondylolisthesis, disc herniation, spinal stenosis, and fractures as well as non-mechanical etiologies such as osteomyelitis and malignancy. History and physical should focus on eliciting red flag symptoms, including traumatic etiology, constitutional symptoms (e.g., fever, weight loss), history of malignancy, intravenous drug use, steroid use, and neurological deficits (e.g., saddle anesthesia, incontinence). The presence of any red flags should prompt further evaluation with imaging. Lumbar strain typically presents with acute low back pain after a precipitating event (e.g., lifting weight) with no red flag signs/symptoms and responds well to conservative management including activity modification, ice, and non-steroidal anti-inflammatory drugs. Prevention measures include strengthening of core muscles and education on proper lifting techniques. Physical therapy is a core component of treating patients with muscle strains.

Knezevic et al. review lower back pain. They note the many potential causes and symptoms that may present. They recommend a multimodal interdisciplinary approach to back pain given the many mechanisms, especially in complex cases.

Incorrect Answers:
Answer A: Disc herniation presents with radicular symptoms due to compression of spinal nerve roots as they exit the spinal canal, manifesting as a burning or shooting pain that radiates down either leg. Dermatomal sensory changes or hyporeflexia may be present depending on the spinal level affected (e.g., reduced Achilles reflex with S1 radiculopathy). The straight leg raise reproduces pain radiating down the leg on the affected side.

Answer B: Lumbar stenosis characteristically causes low back pain or lower extremity paresthesias with walking or standing that resolves when leaning forward (“shopping cart sign”). This is referred to as neurogenic claudication. Involvement of spinal nerve roots can lead to sensory loss and weakness in the lower extremities.

Answer D: Osteoarthritis can cause low back pain and stiffness, but is an age-related degenerative disease that is less likely in this patient who presents acutely after activity. The patient also does not have the typical risk factors for osteoarthritis, which include advanced age, female sex, or obesity.

Answer E: Vertebral compression fracture occurs mainly in osteoporotic patients, whose reduced bone mineral density increases their risk for vertebral body collapse under stress. Vertebral compression fractures present with point tenderness at the midline over the site of fracture. Additionally, this patient has no risk factors for osteoporosis (e.g., advanced age, post-menopausal women, low BMI).

Bullet Summary:
Lumbar strain presents as low back pain without red flag signs or symptoms (e.g., constitutional symptoms, neurologic deficits) and is treated conservatively with activity modification, ice, and core strengthening.


Question:
A 57-year-old man presents to the emergency department with several days of malaise, weakness, and night sweats. Today, he experienced a headache with blurry vision, thus prompting his presentation. The patient has a history of diabetes and is followed closely by an endocrinologist. Otherwise, he has lost 10 pounds over the past month. His temperature is 100°F (37.8°C), blood pressure is 122/90 mmHg, pulse is 84/min, respirations are 16/min, and oxygen saturation is 99% on room air. Physical exam is notable for a thin man but is otherwise unremarkable. His visual acuity is 20/100 in both eyes, though he says that he normally has 20/20 vision. His gait is mildly ataxic as well, but his neurological exam is otherwise nonfocal. Laboratory studies are ordered as seen below.

Hemoglobin: 10 g/dL
Hematocrit: 31%
Leukocyte count: 57,500/mm^3 with 35% blasts
Platelet count: 109,000/mm^3

Serum:
Na+: 139 mEq/L
Cl-: 100 mEq/L
K+: 4.1 Eq/L
HCO3-: 22 mEq/L
BUN: 20 mg/dL
Glucose: 99 mg/dL
Creatinine: 1.1 mg/dL
Calcium: 10.0 mEq/L

Which of the following is the most likely diagnosis?

Answer: Chronic myelogenous leukemia

Explanation:
This patient is presenting with symptoms of malignancy (malaise, weakness, and night sweats) and has a white blood cell count > 50,000/mm^3 in the setting of > 20% blasts, which are concerning for chronic myelogenous leukemia (CML). Given the blurry vision and ataxia in the setting of increased blasts, this patient may be suffering from a hyperviscosity syndrome secondary to a blast crisis, which can be seen in CML.

CML is a neoplastic proliferation of myeloid stem cells. Patients are often asymptomatic and may present with a white blood cell count > 50,000/mm^3. There are many different presentations. The chronic phase presents with < 10% blasts and is often asymptomatic. The accelerated phase has increased blasts, and patients present with fatigue, weight loss, malaise, night sweats, abdominal pain, and hepatosplenomegaly. Finally, the blast phase presents similar to the accelerated phase but with more severe symptoms. The blast phase may evolve into a blast crisis (> 20% blasts) which could cause a hyperviscosity syndrome. Hypervicosity syndrome may require IV fluids and leukapheresis. The most common translocation in CML is the 9;22 translocation which forms the BCR:ABL gene product.

Jain et al. review CML. They note the outcomes in patients in the blast phase in CML and how there are more poor outcomes associated with this phase. They recommend paying close attention and obtaining a CBC with a differential to determine the percent blasts.

Incorrect Answers:
Answer A: Acute lymphoblastic leukemia is more common in pediatric patients and presents with pancytopenia, fatigue, recurrent infections (from leukopenia), and bleeding (from thrombocytopenia). Other findings include systemic symptoms, malaise, fever, bone pain, lymphadenopathy, splenomegaly, and hepatomegaly.

Answer B: Acute myelogenous leukemia is a malignancy of myeloblasts and presents in the elderly. Patients will present with fatigue, malaise, weight loss, anorexia, fever, leukocytosis, anemia (causing fatigue), thrombocytopenia (causing bleeding), and neutropenia (leading to life-threatening infections). Auer rods can be seen on peripheral smear.

Answer C: Chronic lymphocytic leukemia is a monoclonal proliferation of incompetent mature B cells that occurs in elderly men and is the most common form of leukemia in the west. Patients are often asymptomatic and may have a white blood cell count > 50,000/mm^3. When symptomatic, patients may experience chills, weight loss, and weakness (note these symptoms are nonspecific). Peripheral smear will show smudge cells.

Answer E: Multiple myeloma is common in the elderly and presents with CRAB: hyperCalcemia, Renal insufficiency, Anemia, and lytic Bone lesions/Back pain. The diagnosis is supported with protein electrophoresis and confirmed when biopsy demonstrates increased plasma cells.

Bullet Summary:
Chronic myelogenous leukemia presents with increased white blood cells which may be >50,000/mm^3 (possibly with elevated blasts).


Question: A 35-year-old man presents to the emergency department for evaluation of chest pain. The pain starts in his chest and moves into his back, arms, and abdomen. He describes the pain as tearing. He has no known medical history and takes no medications. His temperature is 37.0°C (98.6°F), pulse is 130/min, blood pressure is 210/145 mmHg, respirations are 22/min, and pulse oximetry is 98% on room air. Exam reveals a diaphoretic, anxious-appearing man. Pulses are diminished over the left wrist when compared to the right. A chest radiograph is obtained as shown in Figure A. Which of the following is the most appropriate next step in management?

Answer: CT angiography of the chest, abdomen, and pelvis

Explanation:
This patient with "tearing" chest pain, hypertension, and a chest radiograph demonstrating mediastinal widening likely has an aortic dissection. The most appropriate next step in management would be to obtain CT angiography of the chest, abdomen, and pelvis to confirm the diagnosis.

Aortic dissections develop due to a tear in the intimal layer of the aorta, causing a second blood-filled lumen to form. Risk factors include hypertension, trauma, Marfan syndrome, Turner syndrome, and pregnancy. Prognosis depends on the location and severity of the intimal tear. Aortic dissections are often described by using the Stanford classification, where Type A involves the ascending aorta and Type B involves tears distal to the left subclavian artery. Patients classically present with chest pain described as "tearing" or "ripping" with radiation into the back, arms, or abdomen. Hypertension is common. Chest radiography characteristically demonstrates widening of the mediastinum due to accumulation of blood between layers of the wall of the aorta. Type A dissections are managed with heart rate control, blood pressure control, and surgery. Type B dissections are managed with blood pressure and heart rate control only.

Cooper et al. report on aortic dissections in adolescence. Although rare, aortic dissections have been seen in children with congenital heart disease, connective tissue disorders, or severe traumatic accidents. Severe, migrating abdominal pain should heighten suspicion for this diagnosis. The patient will often look worse clinically than can be explained by physical findings.

Figure A depicts a chest radiograph demonstrating a widened superior mediastinum.

Incorrect Answers:
Answer A: Aspirin is administered for chest pain that is thought to be due to acute coronary syndrome. This patient's presentation, exam, and imaging findings suggest aortic dissection. Aspirin is contraindicated in aortic dissection due to the increased risk for bleeding.

Answer C: Echocardiography offers information on cardiac contractility, valve function, and the presence of effusions. It would not be an appropriate initial diagnostic test in aortic dissection. Transesophageal echocardiography may be used to make the diagnosis in patients who cannot undergo a CTA.

Answer D: Lorazepam would be appropriate for patients presenting with chest pain that is secondary to use of cocaine or other sympathomimetic drugs. Tachycardia, tachypnea, diaphoresis, hyperactive bowel sounds, and dilated pupils suggest a sympathomimetic toxidrome.

Answer E: Serum troponin testing is indicated for risk stratification of patients with suspected acute coronary syndrome.

Bullet Summary:
The most appropriate next step in management for patients with suspected aortic dissection and mediastinal widening on chest radiograph is CT angiography of the chest, abdomen, and pelvis.


Question: A 36-year-old man presents to the office for follow up after initiating antidepressant therapy. Two months ago, he was started on citalopram after several weeks of depressed mood, loss of interest in activities, depressed appetite, and inability to sleep. Today, he reports minimal improvement in his symptoms. He had some nausea after starting the medication, but this has resolved. He denies thoughts of suicide or self-harm. His temperature is 98.6°F (37.0°C), pulse is 80/min, blood pressure is 120/80 mmHg, respirations are 22/min, and oxygen saturation is 97% on room air. Exam reveals a depressed, tired appearing man. Which of the following is the most appropriate next step in management?

Answer: Add mirtazapine

Explanation:
This patient is being treated for depression without improvement in his symptoms after 6 weeks of medication use. In the setting of his reduced appetite and trouble sleeping, mirtazapine is an appropriate medication to add.

SSRIs (including paroxetine, citalopram, fluvoxamine, sertraline, and fluoxetine) are the first line treatment for major depression. For patients in whom an adequate trial of SSRI therapy has been ineffective, the first step in management is a trial of augmentation with a separate agent prior to switching to a different primary antidepressant medication. Mirtazapine, a noradrenergic and specific serotonergic antidepressant, acts by inhibiting pre-synaptic alpha-2 receptors as well as 5HT2 and 5HT3 serotonin receptors. Notably, its side effect profile includes increased appetite and mild sleepiness, making it a good option for depressed patients with insomnia or decreased appetite. Mirtazapine is commonly used to augment primary antidepressant therapy. Augmentation with an additional agent should generally be attempted prior to switching to a different SSRI or other first line medication.

Davies et. al review the pharmacologic management of depression. They note that while evidence is limited, there is some data to suggest benefit in augmentation with a secondary agent prior to switching to another first line therapy.

Incorrect Answers:
Answer B: Electroconvulsive therapy, while often extremely effective, is typically reserved for patients that are actively suicidal, unable to eat, or displaying psychotic symptoms. It is more commonly used after medications have failed.

Answer C: Switching to amitriptyline, a tricyclic antidepressant, would not be appropriate. Tricyclic antidepressants have a negative side effect profile and potential for severe toxicity.

Answer D: Switching to paroxetine, another SSRI medication, may be appropriate. However, this patient's particular constellation of symptoms (decreased appetite and insomnia) suggest that he would likely respond well to mirtazapine.

Answer E: Switching to phenelzine, a monoamine oxidase inhibitor, would not be appropriate. Monoamine oxidase inhibitors have a negative side effect profile and potential for severe drug-drug interaction.

Bullet Summary:
Mirtazapine (a noradrenergic and serotonergic antidepressant) is an appropriate next step for depressed patients with significant insomnia and decreased appetite who fail to respond to a trial of SSRI monotherapy.


Question: A 65-year-old man presents to his primary care physician for stiffness in his arm. He has been having trouble combing his hair and reaching objects that are high on the shelf. The patient has a medical history of type 2 diabetes mellitus, obesity, and hypertension. His current medications include metformin, insulin, lisinopril, and hydrochlorothiazide. The patient leads a sedentary life in which he tends to stay home and watch television. He does not engage in any physical or strenuous activity. His temperature is 98.6°F (37°C), blood pressure is 138/85 mmHg, pulse is 75/min, and respirations are 12/min. On physical exam, the patient has decreased passive and active range of motion of his shoulder. The strength of the patient's upper extremity is 4/5 limited by pain. Which of the following is the most likely diagnosis?

Answer: Adhesive capsulitis

Explanation:
This patient is presenting with stiffness and a decreased range of motion in his shoulders suggestive of a diagnosis of adhesive capsulitis.

Adhesive capsulitis classically presents in elderly, sedentary patients with a chief complaint of stiffness. On physical exam, the key findings are a loss of active, but more importantly, passive range of motion. It is the loss of passive range of motion that suggests a diagnosis of adhesive capsulitis over rotator cuff injuries, biceps tendinopathy, glenohumeral osteoarthritis, and subacromial bursitis. The diagnosis of adhesive capsulitis is made clinically; however, radiography, MRI, and ultrasound can be used to rule out other diagnoses. Treatment includes NSAIDs and physical therapy and can include steroids.

Ramirez reviews the evidence regarding the diagnosis and treatment of adhesive capsulitis. He discusses how non-operative management consists of nonsteroidal anti-inflammatory drugs, short-term oral corticosteroids, intra-articular corticosteroid injections, and physiotherapy. He recommends manipulation under anesthesia and arthroscopic capsule release in patients who fail conservative management.

Incorrect Answers:
Answer B: Biceps tendinopathy presents with pain and weakness overlying the long head of the biceps tendon. This tendon runs in the intertubercular groove on the anterior aspect of the proximal humerus. Patients will often present with pain with resisted flexion of the elbow. Treatment is surgical debridement in patients who fail conservative measures.

Answer C: Glenohumeral osteoarthritis presents with vague and diffuse pain that is exacerbated by activity in addition to a loss of range of motion of the shoulder. Though this patient is experiencing a decreased range of motion, the decreased passive range of motion is more specific for adhesive capsulitis. Treatment is with a total shoulder replacement in patients who fail conservative measures.

Answer D: Rotator cuff impingement presents with pain and weakness of the upper extremity, but also can present with a decreased range of motion as this patient experienced. Of note, the passive range of motion will not be significantly affected by this disease. Treatment is with surgical reconstruction or debridement of the rotator cuff if initial measures fail.

Answer E: Subacromial bursitis presents with localized tenderness, decreased range of motion, pain with motion, and sometimes erythema/edema. Though this patient is experiencing a decreased range of motion and pain with motion, the decreased passive range of motion suggests a diagnosis of adhesive capsulitis. Treatment is with rest and oral anti-inflammatory medications.

Bullet Summary:
Adhesive capsulitis presents with pain and a decreased passive and active range of motion.


Question: A 27-year-old man presents to the emergency department after a bar fight. He was punched in the eye and is having pain and blurry vision. The patient is otherwise healthy and does not take any medications. His temperature is 98.1°F (36.7°C), blood pressure is 132/84 mmHg, pulse is 103/min, respirations are 17/min, and oxygen saturation is 98% on room air. Physical exam is notable for conjunctival injection of the patient’s left eye as shown in Figure A. Visual acuity reveals 20/20 vision in his right eye and 20/40 vision in his left. His left pupil is sluggish to constrict when compared to the right. A fluorescein stain is unremarkable and tonometry reveals a pressure of 45 mmHg in the left eye. Which of the following is the most appropriate next step in management?

Answer: Lateral canthotomy

Explanation:
This patient is presenting after blunt trauma to the eye with eye pain, blurry vision, conjunctival injection, a sluggish pupil, and elevated intraocular pressure (> 20 mmHg) suggesting a diagnosis of a retrobulbar hematoma/hemorrhage causing orbital compartment syndrome. The most important initial step in management is a lateral canthotomy to alleviate retrobulbar pressure.

A retrobulbar hematoma (or hemorrhage) occurs after blunt trauma to the eye. Presenting symptoms may include eye pain, photophobia, proptosis (an eye that appears to be anteriorly displaced), decreased visual acuity, and conjunctival injection. It is important to perform a thorough exam including a slit lamp exam and a fluorescein stain to rule out other traumatic injuries such as a globe rupture. Tonometry can be used to assess for increased intraocular pressure. A pressure > 20 mmHg suggests a diagnosis of orbital compartment syndrome, a vision-threatening condition. Immediate management with a lateral canthotomy is indicated in order to relieve pressure on the optic nerve and retina and save the patient’s vision. Further management may require drainage of the hematoma in the operating room.

Burkat et al. review the technique for performing a lateral canthotomy to relieve pressure in retrobulbar hematoma. The authors first excise the skin and orbicularis muscle at the lateral canthal angle in a horizontal direction for approximately 10 mm. The authors then recommend performing an inferior cantholysis by incising the inferior crus (a thick fibrous band connecting the lateral lower eyelid to the orbital rim) near the orbital rim.

Figure A demonstrates proptosis on physical exam which raises concern for a retrobulbar hematoma that is likely increasing orbital compartment pressure.

Incorrect Answers:
Answer A: CT scan of the head and facial bones would be appropriate if there was a concern for facial fracture. It would delay necessary and vision-saving interventions to perform a CT scan in the setting of orbital compartment syndrome. However, cross-sectional imaging may be performed after the pressure is relieved.

Answer B: Cyclopentolate is a cycloplegic that can be used to reduce pain in traumatic iritis. This typically presents after blunt trauma to the eye with erythema, photophobia, blurry vision, and cell/flare in the anterior chamber on slit lamp exam. A sluggish pupil may also be seen; however, increased intraocular pressure would not be seen in this condition.

Answer D: Orbital ultrasound could be used for diagnoses such as a retinal detachment which presents with flashes of light, floaters, and visual field loss like a “curtain coming down over the eye.” An ultrasound would demonstrate the detached retina in the back of the eye. Management involves elevating the head of the bed and surgical reattachment.

Answer E: Topical timolol and pilocarpine in addition to brimonidine, acetazolamide, and possible iridotomy would be the appropriate management of acute closed-angle glaucoma which presents with a rock-hard eye, blurry vision, a mid-dilated and fixed pupil, as well as a headache. This diagnosis can be supported by elevated intraocular pressure on tonometry. This is unlikely for this patient in the context of trauma.

Bullet Summary:
A retroorbital hematoma can cause orbital compartment syndrome which requires immediate treatment with a lateral canthotomy.


Question: A 23-year-old woman presents to the emergency department with severe abdominal pain. The pain has been dull and progressive, but became suddenly worse while she was exercising. Her medical history is notable for depression, anxiety, and gonococcal urethritis that was appropriately treated. She is sexually active and does not use condoms. She admits to drinking at least 5 standard alcoholic drinks a day. The patient also recently lost a large amount of weight for a fitness show she planned on entering. The patient's current medications include oral contraceptive pills, fluoxetine, alprazolam, ibuprofen, acetaminophen, and folate. Her temperature is 99.5°F (37.5°C), blood pressure is 80/40 mmHg, pulse is 110/minute, and respirations are 15/minute with an oxygen saturation of 96% on room air. On physical exam, you note an athletic young woman with burly shoulders, a thick neck, and acne on her forehead and back. On abdominal exam you note diffuse tenderness with 10/10 pain upon palpation of the right upper quadrant. Intravenous fluids are started and labs are sent. A urinary ß-hCG has been ordered. Which of the following is the most likely the diagnosis?

Obstruction of the common bile duct by radio-opaque stones

Answer: Vascular ectasia within the liver

Explanation:
This patient is presenting with constant right upper quadrant pain in the setting of oral contraceptives (OCP) and likely anabolic steroid use, suggesting a diagnosis of a ruptured hepatic adenoma (HA). The pathophysiology of HA is vascular ectasia from exposure to OCPs and androgens.

A hepatic adenoma typically occurs secondary to exposure to OCPs and androgens (anabolic steroids) causing a generalized vascular ectasia. Both of these drugs should be discontinued in patients with hepatic adenoma. Symptoms include right upper quadrant abdominal pain. Sudden worsening of pain with unstable vitals suggests a ruptured hepatic adenoma. Patients should be managed with fluids and an ultrasound should be performed to support the diagnosis. Additional imaging tests include an abdominal contrast-enhanced CT to better characterize the pathologic anatomy in this disease. The definitive treatment in this disease is surgery in order to remove the hepatic adenoma. In cases of a ruptured hepatic adenomas, patients require transfusion and operative management.

Bioulac-Sage et al. present the current data that are available for classifying hepatic adenomas. They discuss how many of these lesions involve alterations of the HNF1A gene, the JAK/STAT3 pathway, and the CTNNB1 gene. They recommend performing molecular analysis in order to better understand which lesions are likely to undergo malignant transformation.

Incorrect Answers:
Answer A: Ectopic implantation of a blastocyst (ectopic pregnancy) that has ruptured could present similarly to what this patient is experiencing. Symptoms would include lower abdominal pain and unstable vitals. However, this patient's pain is more pronounced in the right upper quadrant and is occurring in the setting of OCP and possible anabolic steroid use.

Answer B: Inflammation of the pancreas represents a diagnosis of pancreatitis. This would present with epigastric pain after a fatty meal or alcohol consumption. Though this patient does drink more than recommended and should be counseled to reduce her consumption, the pain began after exercising at the gym and there are no other symptoms of pancreatitis.

Answer C: Obstruction of blood flow through the hepatic vein causes Budd-Chiari syndrome, which presents with a non-specific triad of abdominal pain, ascites, and hepatomegaly in the setting of a hypercoagulable state (factor V Leiden, polycythemia vera, OCP use, and paroxysmal nocturnal hemoglobinuria). Though this patient has risk factors for this pathology, they do not have any classic symptoms.

Answer D: Obstruction of the common bile duct with radio-opaque stones would present with colicky right upper quadrant pain in a patient that is "fat, female, fertile, and forty." Though the pain presented in this case is localized to the right upper quadrant, it is not colicky and there is not a positive Murphy sign described. OCP's are a risk factor for cholesterol stones as are rapid weight loss, both of which this patient has. This is a strong possibility on the differential; however, the symptoms presented suggest a diagnosis of ruptured hepatic adenoma given the demographics of the patient.

Bullet Summary:
A hepatic adenoma presents with right upper quadrant pain in the setting of OCP and/or androgen use and can rupture leading to unstable vitals.


Question: A 56-year-old man presents from prison with 1 month of subjective fevers, chills, cough, and night sweats. He noticed a gradual weight loss over the past year despite no changes to his diet or physical activity. He has never smoked cigarettes but does have a history of opiate use prior to incarceration. He does not take any medications. His temperature is 100.8°F (38.2°C), blood pressure is 142/88 mmHg, pulse is 78/min, and respirations are 12/min. Physical exam reveals a thin, ill-appearing man. Pulmonary auscultation reveals faint, inspiratory crackles in the right upper lobe. His chest radiograph is shown in Figure A. Which of the following is the most appropriate next step in management?

Rifampin, isoniazid, pyrazinamide, and ethambutol (RIPE) therapy

Answer: Rifampin, isoniazid, pyrazinamide, and ethambutol (RIPE) therapy

Explanation:
This patient likely has active tuberculosis (TB), as evidenced by his symptoms (fever, night sweats, cough, and weight loss), inmate status, and apical cavitary lesion on chest radiograph. He should be treated with RIPE therapy.

An active TB infection should be suspected in patients with a febrile illness, cough, night sweats, and weight loss along with epidemiological risk factors for TB infection. Risk factors include residence in or previous visits to endemic regions, work in hospitals or nursing homes, imprisonment, and immunosuppression. Treatment typically requires 2 phases: an intensive phase involving 2 months of rifampin, isoniazid, pyrazinamide, and ethambutol (RIPE) therapy and a continuation phase involving 4 additional months of just isoniazid and rifampin. Vitamin B6 (pyridoxine) should be taken with isoniazid to prevent peripheral neuropathy. Rifampin, isoniazid, and pyrazinamide use should be monitored for hepatotoxicity. Ethambutol can cause optic neuropathy.

Conradie et al. discuss the use of a bedaquiline-pretomanid-linezolid (BPal) regimen in the treatment of extensively drug-resistant tuberculosis. The authors find that most patients treated with BPal have a favorable outcome (no treatment failure or disease relapse) after 6 months. The authors recommend the use of this regimen in highly drug resistant TB.

Figure/Illustration A demonstrates a right upper lobe cavitating lesion (arrow) that resulted in extensive necrosis and fibrosis. These lesions are usually localized to the upper regions of the lung due to favorable oxygen concentrations in the apex.

Incorrect Answers:
Answer A: Ampicillin-sulbactam can be used as empiric treatment for a lung abscess to cover anaerobic pathogens and facultative anaerobic streptococci. A lung abscess is associated with aspiration risk factors (such as alcohol use) or poor dentition.

Answer B: Biopsy may be indicated for a solitary cavitary nodule that is suggestive of malignancy. In this case, the patient's inmate status, along with his fever, night sweats, and cough are more suggestive of an infectious rather than malignant etiology.

Answer C: Itraconazole can be used to treat chronic pulmonary aspergillosis. These patients typically have prior or current lung disease such as chronic obstructive pulmonary disease or tuberculosis. The classic air crescent sign may be seen on imaging in a patient with an aspergilloma, a form of pulmonary aspergillosis in which a fungal ball develops within an existing cavitary lesion.

Answer D: Vancomycin can be used to treat a lung abscess due to methicillin-resistant Staphylococcus aureus. S. aureus pneumonia classically presents as a secondary infection that follows an influenza infection.

Bullet Summary:
Active tuberculosis infection should be treated with rifampin, isoniazid, pyrazinamide, and ethambutol (RIPE) therapy.


Question: A resident physician places a patient’s home medications in for their admission orders during an overnight admission. They order the patient’s home medications including clobazam; however, they accidentally order clonazepam. Subsequently, the patient is over-sedated and has to be transferred to the ICU for airway monitoring. Which of the following is the most appropriate method for preventing future similar occurrences?

Add an alert in the electronic medical system for medications that sound similar

Enter medications only on morning rounds with multiple providers

Have nursing perform the medication reconciliation

Reprimand and educate the resident to check medications more carefully

Verify the patient’s home medications with the patient

Answer: Add an alert in the electronic medical system for medications that sound similar

Explanation:
A medical error occurred where 2 similar-sounding medications were confused, leading to an adverse event. The most appropriate way to prevent this error from occurring is a system-based approach, such as adding an alert in the electronic medical system for medications that sound similar.

Medical errors commonly occur in the medical system given the complexity of delivering patient care. The best way to prevent future errors from occurring is a systems-based approach where the system is built to catch errors rather than relying on the diligence of staff. In a systems-based approach, there is an algorithmic method set in place for situations where errors are common. Examples of systems-based approaches to avoiding medical errors include time-outs for procedures, use of the electronic medical record and ordering system to generate stops and checks, and built-in procedures such as a pharmacist verifying all medical orders. The best way to prevent future errors, when possible, is a systems-based approach as it does not rely solely on individuals given that individuals are fallible and may not always avoid mistakes.

Condren et al. review a systems based approach in the medical system. They note that a systems-based approach reduces medication errors. For this reason, systems-based approaches are recommended whenever possible.

Incorrect Answers:
Answer B: Entering medications only on morning rounds with multiple providers is not a plausible strategy as patients will not receive medications they may need at other times, such as overnight. It is always a good idea to verify medications with the team on morning rounds to catch any possible errors that may be missed, but this would not necessarily fix errors that occur at other times of the day.

Answer C: Having nursing perform the medication reconciliation is not the best solution in this case, as the core problem was that the wrong medication was entered due to similar-sounding medication names. However, it is always a good idea to have multiple providers (e.g., nurses, pharmacists) verify information, check this with the physician team, and then verify the dose and route of administration when giving the medication.

Answer D: Reprimanding and educating the resident to check medications more carefully is not a solution to this problem. It does not seem that the resident does not understand the pharmacology or medication prescribed but made an understandable error. Explaining the need for care is important; reprimanding the resident is not.

Answer E: Verifying the patient’s home medications with the patient should always be performed, but it would not fix this issue with similar-sounding medications. It would catch errors such as new medications that are not on the patient’s medication list or out-of-date medications remaining on the list.

Bullet Summary:
A systems-based approach is the most appropriate way to prevent future errors from occurring.


Question: A 33-year-old man presents to the emergency department after slamming his finger in the car door 5 hours ago. He initially experienced pain which is currently well controlled with acetaminophen. The patient is otherwise healthy and does not take any medications. His temperature is 98.5°F (36.9°C), blood pressure is 123/79 mmHg, pulse is 90/min, respirations are 11/min, and oxygen saturation is 97% on room air. Physical exam is notable for the finding in Figure A. A radiograph of the affected digits shows a smooth cortex without disruption of the bone. Which of the following is the most appropriate management for this patient?

Answer: Trephination

Explanation:
This patient is presenting after trauma to his finger with a subungual hematoma. Given that he has no other associated injuries, trephination is the only management indicated.

A subungual hematoma occurs after trauma to the finger leading to a collection of blood under the fingernail. Depending on the mechanism, this can be associated with a distal phalanx fracture. Evaluation for a fracture should include a thorough history, exam, and radiography. If there are no other signs of injury including nailbed dislocation or an open fracture, then management requires only trephination (putting a hole in the nail to allow blood to drain) as this alleviates pressure on the nailbed matrix thus preventing possible irreversible damage.

Rsoer et al. compare nail bed repair to nail trephination for subungual hematomas in children. The authors find that there was no difference in complications or outcomes between nail bed repair and trephination; however, the cost in the nail trephination group was lower. The authors recommend nail trephination for children with a subungual hematoma and an intact nail and nail margin.

Figure/Illustration A shows the physical exam finding of a subungual hematoma with a collection of blood underneath the fingernail bed (green circle).

Incorrect Answers:
Answer A: Excision and histological examination could be appropriate management of melanoma, which may present under the fingernails with a hyperpigmented, irregular skin lesion, or a “barcode” appearance if it is at the base of the nail. A spontaneous subungual hematoma could be suggestive of melanoma; however, in the setting of trauma, it is a much less likely diagnosis.

Answer B: Fingernail removal should only be performed if there is also nail avulsion or nail fold disruption to allow for inspection of the nail bed and repair of any laceration. Failure to repair a nailbed laceration could lead to permanent deformity of the fingernail when it regrows.

Answer C: Observation is inappropriate as the accumulation of blood under the nail in a subungual hematoma could lead to ischemia and permanent injury to the nailbed. When a subungual hematoma is present, trephination is indicated.

Answer D: Operative repair may be necessary for fractures; however, this patient has no fracture and only has a subungual hematoma which can be drained easily.

Bullet Summary:
A subungual hematoma is common after trauma, presents with a collection of blood under the fingernail, and should be treated with trephination.


Question: A 27-year-old woman presents to her primary care physician for an abnormal vaginal discharge. The patient has engaged in unprotected intercourse with 12 different partners. She has a medical history of asthma, IV drug abuse, and depression. She has 1 to 2 alcoholic drinks per day. She feels ashamed of her behavior and is requesting treatment for her condition and advice for safe sex. The patient is given antibiotics and is advised on safe sex practices. The patient presents to the emergency department 3 days later with a complaint of a rash. She states that every time she has sex a rash has emerged on her skin. Her temperature is 99.5°F (37.5°C), blood pressure is 127/68 mmHg, pulse is 91/min, respirations are 14/min, and oxygen saturation is 98% on room air. A physical exam is notable for the finding in Figure A. Which of the following is the most likely cause of this patient's symptoms?

Answer: Antigen exposure

Explanation:
This patient is presenting with urticaria whenever she engages in sexual intercourse suggesting a latex allergy (found in condoms). These allergies are due to antigen exposure.

Anaphylaxis and urticaria are immunologically mediated responses to environmental antigens that are typically IgE-mediated. This results in crosslinking of antigen receptors and the subsequent release of histamine and other inflammatory signals. Patients can present with a spectrum of symptoms from urticaria (hives alone) all the way to full-blown anaphylaxis (hypotension, tachycardia, and bronchoconstriction). Minor cases can be treated with avoidance of antigen exposure. Anaphylaxis is treated with intramuscular epinephrine (1:1,000).

Gawchik reviewed the evidence regarding the diagnosis of latex allergy. She discusses how the diagnosis is primarily made by observing the relationship between exposure and symptoms. She recommends avoidance of latex in these patients.

Figure/Illustration A is a clinical photograph that demonstrates dermal edema and urticaria (red circles). This can occur secondary to allergen exposure such as from a new drug or latex.

Incorrect Answers:
Answer B: Drug reaction could be possible if this patient has an antibiotic allergy (ceftriaxone is a treatment for gonorrhea); however, a rash that only occurs during intercourse is more likely related to latex exposure.

Answer C: Infection is possible given this patient’s IV drug abuse and risky behavior; however, the hives present in this patient are likely not related to an infection. Infectious rashes tend to be painful, ulcerative, or vesicular.

Answer D: IV drug use could expose this patient to any number of foreign substances that could induce an allergic reaction; however, the symptoms that are associated with sexual intercourse point toward latex exposure.

Answer E: Photosensitivity would not present as hives but could occur in this patient given that doxycycline is an appropriate drug to treat her initial sexually transmitted infection and offers coverage for Chlamydia trachomatis. Patients would present with a photosensitive rash.

Bullet Summary:
Anaphylaxis and urticaria can occur secondary to latex exposure (such as from condoms or gloves).