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 57-year-old woman presents to her primary care physician with weakness for the past 6 months with symptoms that have worsened recently. She feels fatigued, depressed, and has gained 10 pounds which she attributes to feeling too weak to go to the gym. She was recently treated for an ear infection with an antibiotic which she completed 3 weeks ago, and experienced a rash which she believes was an allergic reaction to her treatment. The patient has a medical history of diabetes mellitus that is well-controlled with insulin and metformin. She has been admitted multiple times for hypoglycemia secondary to missing meals. Her temperature is 99.5°F (37.5°C), blood pressure is 127/68 mmHg, pulse is 80/min, respirations are 17/min, and oxygen saturation is 98% on room air. Physical exam is notable for 2/5 strength in the patient's upper and lower extremities, sparse fine hair on her body, and a rash on her face and arms. Laboratory values are ordered as seen below. Serum: Na+: 139 mEq/L K+: 3.3 mEq/L Cl-: 100 mEq/L HCO3-: 25 mEq/L BUN: 20 mg/dL Glucose: 70 mg/dL Creatinine: 1.1 mg/dL Ca2+: 10.2 mg/dL AST: 12 U/L ALT: 10 U/L A muscle biopsy is obtained as seen in Figure A. Which of the following is the most likely explanation for this patient's presentation?

Answer: Inclusion body myositis

Explanation:
This patient who presents with weakness and a rash has a biopsy suggestive of inclusion body myositis.

Inclusion body myositis presents with an insidious onset of weakness, a mildly elevated CRP and CK, and a rash. A muscle biopsy in this disease will demonstrate endomysial inflammation with basophilic-rimmed vacuoles within the muscle fiber sarcoplasm. Electromyography is typically abnormal, and the most accurate/confirmatory test is a muscle biopsy. There is no cure for this disease and no standard course of treatment. Corticosteroids are not usually effective but intravenous immunoglobulins can be effective.

Naddaf et al. review the evidence regarding the diagnosis and treatment of patients with inclusion body myositis. They discuss how this disease is still refractory to treatment. They recommend a muscle biopsy to establish a definitive diagnosis.

Figure/Illustration A is a muscle biopsy demonstrating endomysial inflammation with basophilic-rimmed vacuoles (red circle) within the muscle fiber sarcoplasm. These findings are classically seen in patients with inclusion body myositis.

Incorrect Answers:
Answers 1 & 5: Dermatomyositis and polymyositis present similarly with muscle weakness and an elevated CK, CRP, and aldolase. However, dermatomyositis presents with dermatologic findings. A biopsy would demonstrate inflammation surrounding the muscle fascicle (dermatomyositis) or within the muscle fascicle (polymyositis). Treatment may include azathioprine and methotrexate.

Answer B: Hypokalemia could present with weakness and cardiac abnormalities. Though this patient is hypokalemic, her biopsy demonstrates inclusion body myositis. Treatment of hypokalemia is with potassium repletion.

Answer C: Hypothyroidism presents with depression, fatigue, scarce lanugo, myopathy, and weight gain (as this patient has). Though myopathy from hypothyroidism is plausible, her symptoms of weakness have a confirmatory biopsy. Treatment of hypothyroidism is with thyroid hormone replacement.

Bullet Summary:
Inclusion body myositis presents with weakness and an elevated CRP/CK with a muscle biopsy demonstrating endomysial inflammation with basophilic-rimmed vacuoles within the muscle fiber sarcoplasm.


Question: A 6-month-old girl is brought to the pediatrician by her father for a scheduled check-up. She was in her usual state of health until 6 weeks ago when she was hospitalized for bacterial pneumonia. She received amoxicillin and had a resolution of her symptoms. Her father reports that she seems “back to normal.” She can roll over by herself and can sit up without support. She often babbles but sometimes does make identifiable sounds like “dada” and “baba.” They recently started feeding her mushy cereal, which she seems to like but occasionally spits up. She has started teething and sometimes becomes “fussy.” Vital signs are within normal limits. A physical examination is unremarkable. The patient’s father brought a 4-week follow-up chest radiograph taken at the hospital, as shown in Figure A. Which of the structures labeled in Figure A would be most likely to change in response to another infectious illness?

Answer: A

Explanation:
The thymus gland (labeled in A) is visible on a chest radiograph in infants and will change in response to illness due to its immunologic role.

The thymus gland is the site of T-cell maturation. The thymus is visible on a chest radiograph in infants and continues to grow throughout childhood. It is located in the anterior part of the superior mediastinum. On a chest radiograph, the thymus may appear as a “widened mediastinum,” continuous with the superior border of the heart (Figure A) or as a triangular-shaped opacity known as the thymic “sail sign," located towards the right of the mediastinum. At puberty, the gland will decrease in size and eventually be replaced by fatty tissue.

Askin and Young review the evidence regarding the history and function of the thymus. They discuss how this structure is involved in immune function. They recommend monitoring for the absence of this structure in immunodeficient patients.

Figure A shows a normal chest radiograph of an infant with a normal cardiothymic contour.

Incorrect Answers:
Answer B: B points to the trachea. Deviation of this structure can be seen in patients with tension pneumothorax. Treatment is with needle thoracostomy followed by chest tube placement.

Answer C: C points to the apex of the heart. This structure can be enlarged in congenital heart conditions. Treatment is with surgical correction of these conditions.

Answer D: D points to the stomach. This structure can be abnormal in patients with pyloric stenosis. Treatment is with pyloromyotomy.

Answer E: E points to the diaphragm. This structure can be abnormal in patients with diaphragmatic hernias. Treatment is with surgical closure of the defect.

Bullet Summary:
The thymus is normally visible on a pediatric chest radiograph, but it is replaced by fatty tissue after puberty.


Question: A 57-year-old man presents to the emergency department for weight loss and abdominal pain. The patient has felt steadily more fatigued over the past month and has lost 22 pounds without effort. Today, he fainted prompting his presentation. The patient has no significant medical history. He does have a 33-pack-year smoking history and drinks 4 to 5 alcoholic drinks per day. His temperature is 99.5°F (37.5°C), blood pressure is 100/58 mmHg, pulse is 100/min, respirations are 17/min, and oxygen saturation is 98% on room air. The patient is very thin and appears pale. Stool fecal occult blood testing is positive. A CT scan of the abdomen is performed demonstrating a mass in the colon with multiple metastatic lesions scattered throughout the abdomen. The patient is informed of his diagnosis of metastatic colon cancer. When the patient conveys the information to his family, he focuses his efforts on discussing the current literature in the field and the novel therapies that have been invented. He demonstrates his likely mortality outcome which he calculated using the results of a large multi-center study. Which of the following is this patient most likely demonstrating?

Answer: Intellectualization

Explanation:
This patient is using facts and logic to emotionally distance himself from his stressful diagnosis. This ego defense method is suggestive of intellectualization.

Intellectualization typically occurs in patients who have received a very stressful diagnosis or bad news for a close loved one. They will often focus on the science and research of their disease rather than focus on emotionally processing this stressful event. This is a way of distancing themselves from the diagnosis and their circumstances. These patients may have difficulty connecting with others because they become extremely focused on data.

Arnold reviews the evidence regarding the diagnosis of intellectualization. He discusses how this term can either refer to the isolation of affect or the general use of reason. He recommends a better understanding of how this ego defense works.

Incorrect Answers:
Answer A: Dissociation is the detachment of the mind from the emotional state/body. A more specific diagnosis for this patient would be intellectualization as he is detaching himself from the emotional state of the diagnosis and instead focusing on the science behind his condition.

Answer C: Optimism is trying to find the best in a bad situation. This patient's focus on treatment outcomes and absence of emotion suggests intellectualization as the employed defense mechanism. Patients who are optimistic will still be able to emotionally process information.

Answer D: Pessimism is finding the worst in most situations. Pessimism would be a possible answer if the patient had a very treatable disease but thought that poor outcomes would occur regardless.

Answer E: Rationalization is the use of logic or reasoning (that can be inappropriate) in order to substantiate one's behavior even when it is inappropriate. An example is justifying theft because a person was in need.

Bullet Summary:
Intellectualization is the use of facts and logic to distance oneself from a stressful situation.


Question: A 55-year-old man presents to his primary care physician with persistent symptoms of depression. He started taking fluoxetine 3 weeks ago when he was diagnosed with major depressive disorder after a divorce. Since then, he notes that his symptoms are roughly unchanged. His other medications include albuterol. His temperature is 99.3°F (37.4°C), blood pressure is 132/88 mmHg, pulse is 77/min, respirations are 14/min, and oxygen saturation is 99% on room air. Physical exam reveals a depressed affect. His neurologic exam is non-focal. A serum thyroid stimulating hormone (TSH) resulted from his last visit and is noted to be 4.8 µU/mL (normal: 0.5-5 µU/mL). Which of the following is the most appropriate next step in management?

Answer: Maintain dose of current medication

Explanation:
This patient is presenting with major depressive disorder but has not given his current selective serotonin reuptake inhibitor (SSRI) at least 4 weeks to begin working. Thus, he should be reassured and maintained on the current dose of his SSRI, with follow-up after the 4 week mark to see if his symptoms have improved.

Major depressive disorder is managed initially with cognitive behavioral therapy and pharmacotherapy. The typical first-line medication is an SSRI. SSRIs may take at least 4 weeks or more to begin working, so patients that return before this time period should be reassured and encouraged to let the medication take effect as long as they are not experiencing suicidal thoughts or intent. If the medication is not working after at least 4 weeks, the next steps in management could include increasing the dose of the current medication, changing SSRIs, adding another antidepressant agent, or adding a low dose of levothyroxine. All patients with suicidal ideation and either intent or a plan to hurt themselves should be hospitalized involuntarily.

Gautam et al. discuss the current management algorithms for major depressive disorder. They note different options including CBT and pharmacotherapy. They recommend appropriate treatment with a first-line agent based on the patient and their circumstances.

Incorrect Answers:
Answer A: Administering levothyroxine is appropriate as an augmenting agent in patients who do not have an improvement in symptoms on SSRIs or other antidepressants even if their TSH is within the normal range. However, it would not be attempted at this point given this patient has not given his current medication sufficient time to begin working. There is limited evidence to support its use overall. Note that this patient's TSH is within normal limits. In some cases, T3 administration is used in refractory depression.

Answer B: Changing the medication to bupropion could be appropriate in patients who want to avoid weight gain, those who want to quit smoking, or those who are trying to avoid sexual side effects. It also is an appropriate second-line agent or could be added to a first-line agent; however, this patient’s current medication should be tried for at least 4 weeks before changing medications.

Answers 3 & 4: Changing medication to escitalopram or increasing the dose of the current medication are both viable strategies if a patient has failed to improve on their first medication after at least 4 weeks on the medication. Increasing the dose early may lead to symptoms of serotonin excess when the drug takes effect.

Bullet Summary:
SSRIs are the first-line agents in the management of major depressive disorder and should be tried for at least 4 weeks before changing the treatment regimen.


Question: A 24-year-old man presents to the emergency department with abdominal pain, nausea, and vomiting. The symptoms began towards the end of running a marathon and persisted after finishing the race. The patient is otherwise healthy and has no other medical problems. His temperature is 98.0°F (36.7°C), blood pressure is 105/71 mmHg, pulse is 113/min, respirations are 19/min, and oxygen saturation is 98% on room air. Physical exam reveals a distended and tender abdomen. A radiograph is performed as seen in Figure A. Which of the following is the most likely diagnosis?

Answer: Cecal volvulus

Explanation:
This young, healthy patient presents with abdominal pain, nausea, vomiting, and a distended, tender abdomen with a radiograph demonstrating the "coffee bean sign," likely has a cecal volvulus.

Cecal volvulus is the second most common cause of volvulus after sigmoid volvulus and presents with abdominal pain, constipation, vomiting, abdominal distention, and a tympanitic abdomen. It is more common in young patients who are active (e.g. marathon runners). The classic conventional radiographic finding in cecal volvulus is the coffee bean sign, in which closed loops of intestine distend with gas, making visible the medial and lateral walls of dilated bowel. Diagnosis of cecal volvulus can be confirmed with a CT scan. Management involves analgesia, intravenous fluids, and surgical detorsion.

Hasbahceci et al. review the presentation, diagnosis, and management of cecal volvulus. The authors find that abdominal radiography has a low sensitivity for cecal volvulus. The authors recommend surgical management of cecal volvulus with resection with right hemicolectomy and primary ileocolic anastomosis.

Figure/Illustration A is a radiograph demonstrating the "coffee bean" sign which is suggestive of a cecal volvulus.

Incorrect Answers:
Answer B: Ileus presents after surgery or manipulation of the intestines with decreased peristalsis of the intestine leading to a failure to pass gas or have bowel movements. Treatment involves treating any electrolyte abnormalities, encouraging ambulation, and avoiding medications that decrease peristalsis (such as opioids).

Answer C: Ogilvie syndrome occurs when the colon wall is not appropriately undergoing peristalsis leading to a dilated colon with abdominal distension. It is more common in the elderly and critically ill patients. Treatment involves the placement of a rectal tube to decompress the intestines and treatment of any underlying medical conditions.

Answer D: Sigmoid volvulus is more common in elderly and critically ill patients and presents with constipation, an absence of bowel movements, and a distended, tympanitic abdomen. Although the coffee bean sign may also be seen in patients with sigmoid volvulus, patients tend to be older. In addition, plain radiography typically demonstrates multiple air-fluid levels in a sigmoid volvulus versus usually only a single air-fluid level in a cecal volvulus. Treatment involves flexible sigmoidoscopy and surgery.

Answer E: Small bowel obstruction presents with a distended and tympanitic abdomen with nausea, vomiting, and an absence of flatus or bowel movements. Radiography may demonstrate distended bowel and air-fluid levels, and the most accurate test is a CT scan of the abdomen. It occurs secondary to adhesions entrapping the bowel. Management involves the placement of a nasogastric tube, intravenous fluids, and surgery.

Bullet Summary:
Cecal volvulus presents in younger patients with abdominal pain, distention, constipation, nausea, vomiting, and the "coffee bean" sign on radiography.


Question: A 26-year-old woman presents to the emergency department because she feels as though her heart is "beating out of her chest." She states that she feels well apart from the discomfort of that sensation. Her temperature is 97.9°F (36.6°C), blood pressure is 124/84 mmHg, pulse is 180/min, respirations are 22/min, and oxygen saturation is 98% on room air. An ECG is obtained as seen in Figure A. After unsuccessful attempts at vagal maneuvers, the emergency physician administers an IV medication. The effect of the medication wears off in seconds. Which of the following is a potential side effect of this medication?

Answer: Flushing

Explanation:
This patient presents with a narrow complex tachycardia that is regular which is suggestive of supraventricular tachycardia (SVT) and was pharmacologically cardioverted with adenosine (as it has a very short half-life). Side effects of adenosine include flushing, hypotension, bronchospasm, and heart block.

SVT presents with a narrow-complex, regular tachycardia. The diagnosis is made with these findings on ECG. Management in an unstable patient is centered on cardioversion. Otherwise, the first step in management is centered on vagal maneuvers. If these fail, adenosine is the first-line pharmacologic treatment. While a relatively safe drug, side effects of adenosine include hypotension, heart block, flushing, and bronchospasm. Patients may also report a "sense of impending doom" following administration, thought to be the result of the transient asystole adenosine produces. Persistent SVT refractory to adenosine may be further managed with calcium channel blockers, beta blockers, or cardioversion.

Colucci et al. review the diagnosis and management of common types of supraventricular tachycardias. The most common types of supraventricular tachycardia are caused by a reentry phenomenon producing accelerated heart rates. Symptoms may include palpitations, chest pain, lightheadedness or dizziness, and dyspnea. If Wolff-Parkinson-White syndrome is present, expedient referral to a cardiologist is warranted because ablation is a potentially curative option.

Figure A is an ECG demonstrating SVT. Note the regular narrow complex tachycardia that is a defining feature of this condition.

Incorrect Answers:
Answer A: A disulfiram-like reaction was once thought to be associated with medications such as metronidazole. Metronidazole is an antibiotic that covers anaerobes. When alcohol is consumed in a patient on disulfiram, headache, malaise, nausea, and vomiting may be experienced.

Answer C: Photosensitivity is associated with medications such as sulfonamides, amiodarone, and tetracycline. Patients should be advised to stay out of the sun on these medications.

Answer D: Seizures are not associated with adenosine. Isoniazid, bupropion, imipenem/cilastatin, tramadol, enflurane, and metoclopramide are all known to increase the risk of seizures. Seizures often present with tonic-clonic activity, tongue biting, urinary incontinence, and a postictal phase.

Answer E: Tachycardia can be associated with medications such as atropine which reduce vagal tone on the heart increasing the heart rate. Medications that block the AV node would be expected to cause bradycardia.

Bullet Summary:
Adenosine is a first-line pharmacological agent in supraventricular tachycardia and can cause hypotension, heart block, flushing, and bronchospasm.


Question: A 69-year-old man presents to his primary care physician for a general checkup. The patient works as a farmer and gardens in his spare time. He has a medical history of poorly managed type 2 diabetes mellitus and irritable bowel syndrome. His current medications include lisinopril, metformin, insulin, fiber supplements, and a multivitamin. On physical exam, there is a calm, obese gentleman. Inspection of the patient's scalp reveals the finding shown in Figure A. The patient is sent home and instructed to keep a blood glucose journal. Three months later, the patient returns with his glucose journal. In addition, he complains of a cut on his scalp that is not seeming to heal. The patient's glucose journal reveals an average blood glucose of 175 mg/dL. His temperature is 98.8°F (37.1°C), blood pressure is 134/86 mmHg, pulse is 80/min, and respirations are 13/min. On inspection of the patient's scalp, the finding in Figure B is noted. Which of the following is the most likely diagnosis?

Answer: Squamous cell carcinoma

Explanation:
This patient with a non-healing ulcer on the site of a previous actinic keratosis most likely has sustained progression of the lesion to squamous cell carcinoma.

Squamous cell carcinoma (SCC) is a common dermatological malignancy. Patients can present with actinic keratosis, which is a pre-malignant lesion in sun-exposed areas. These lesions can progress to squamous cell carcinoma if risk factors such as sun exposure continue. The presentation of SCC is typically an ulcerative lesion in a sun-exposed area. A biopsy will demonstrate atypical keratinocytes and malignant cells, invasion into the dermis, and keratin “pearls” on histology. Treatment is with wide local surgical excision with histologic confirmation of negative margins.

Waldman and Schmults present a review of the evidence regarding the epidemiology and treatment of squamous cell skin cancer. They discuss how the incidence of this disease continues to increase due to an aging population. They recommend local excision and treatment due to the risk of metastasis.

Figure/Illustration A is a clinical photograph demonstrating a rough scaly patch on the skin (red circle). This finding is consistent with actinic keratosis, which is a pre-malignant lesion typically found on sun-exposed areas.

Figure/Illustration B demonstrates an ulcerative lesion with wound formation on the skin (red circle). This finding is consistent with squamous cell carcinoma, a malignant lesion that can progress from actinic keratosis.

Incorrect Answers:
Answer A: Actinic keratosis represents a pre-malignant condition that this patient initially presented with (as demonstrated in Figure A). His current presentation reflects SCC, a progression from actinic keratosis given the new ulceration and non-healing wound.

Answer B: Basal cell carcinoma presents with a shiny or pearly appearance, rather than the ulcerative appearance that is seen in SCC. This disease should be treated with surgical excision.

Answer C: Melanoma presents with a pigmented lesion that has an irregular border, an uneven shape, and areas that differ in pigmentation. Patients with melanoma should undergo surgical staging as this disease can become metastatic and should be treated with surgical excision.

Answer D: Poor wound healing secondary to diabetes would be possible if there was a history of trauma to the scalp. The history of actinic keratosis and the current ulcerative lesion, point more toward a diagnosis of SCC. Non-healing wound in patients with diabetes are usually located on the foot rather than on the scalp.

Bullet Summary:
Actinic keratosis is a pre-malignant lesion that occurs in sun-exposed areas that can progress to squamous cell carcinoma.


Question: A 25-year-old woman presents for a new patient physical exam. Aside from occasional shin splints, she has a relatively unremarkable medical history. She takes oral contraceptive pills and a multivitamin daily. All of her age appropriate immunizations are up to date. Her periods have been regular, occurring once every 28 to 30 days with normal flow. She is sexually active with 2 partners, who use condoms routinely. Her prior pap smear was performed last year and was normal. Her mother has diabetes and coronary artery disease, and her father passed away at age 45 after being diagnosed with colon cancer at age 40. Her grand-aunt underwent bilateral mastectomies after being diagnosed with breast cancer at age 60. Her temperature is 36.7°C (98°F), blood pressure is 115/80 mmHg, pulse is 65/min, respirations are 12/min, and oxygen saturation is 100% on room air. Her physical exam is within normal limits. Which of the following is the most appropriate recommendation for this patient?

Pap smear with human papillomavirus (HPV) DNA testing now

Answer: Colonoscopy in 5 years

Explanation:
This patient is presenting for a health evaluation with a family history significant for her father's death due to colon cancer at age 45. She should thus get a colonoscopy when she reaches the age 10 years prior to her father's age of diagnosis or in 5 years (at age 30).

The age threshold for colon cancer screening varies based on the patient's risk factors, including family history of colon cancer, inflammatory bowel disease, and/or genetic disorders. In the absence of significant risk factors, colonoscopies can be used for screening starting at age 45 and repeated every 10 years if results are normal. If there is family history of colon cancer (one or more first degree relatives, including parent, sibling, or child), colonoscopies should be recommended starting at age 40 or 10 years prior to the age of the family member's diagnosis, whichever is earlier. Polyps or grossly abnormal colon tissue may be biopsied for grading and guide further diagnostic imaging workup.

Aasma et al. review the clinical guidelines for colorectal cancer screening. They found that recent epidemiological data shows an increase in the incidence of colorectal cancer in individuals younger than 50 years. They recommend starting colonoscopy screening at 45 years of age in the average-risk adult population.

Incorrect Answers:
Answer B: Colonoscopy in 10 years is reasonable, but it is not the earlier of the 2 age thresholds mentioned above.

Answer C: Pap smear with HPV DNA screening for cervical cancer is indicated every 5 years for women aged 30 to 65 who wish to extend the screening interval from the 3 year interval for pap smear alone.

Answer D: Pap smear alone is indicated every 3 years for women of ages 21 to 65.

Answer E: Mammogram to screen for breast cancer is recommended every 2 years for women aged 50 to 74.

Bullet Summary:
For patients with a family history of colon cancer, screening should start at age 40 or 10 years prior to the age of the family member's diagnosis, whichever is earlier.


Question: A 67-year-old man is seen on the surgical floor after a transplant procedure. The previous day, the patient had a renal transplant from a matched donor. He is currently recovering and doing well. The patient has a medical history of IV drug use, diabetes mellitus, oral cold sores, hypertension, renal failure, and dyslipidemia. The patient's current medications include lisinopril, atorvastain, insulin, and aspirin. Prior to the procedure, he was also on dialysis. The patient is started on cyclosporine. The patient successfully recovers over the next few days. His temperature is 98.5°F (36.9°C), blood pressure is 121/76 mmHg, pulse is 70/min, and respirations are 13/min. Which of the following medications should be started in this patient?

Answer: TMP-SMX

Explanation:
This patient is presenting status post renal transplant and is currently on immunosuppressive therapy. This patient should be started on TMP-SMX as prophylaxis against Pneumocystis jiroveci pneumonia (PJP).

After a transplant procedure, patients are started on immunosuppressive therapy in order to avoid rejection of the transplanted organ. The most important interventions for a patient after a transplant procedure are to receive all of their vaccinations and to receive TMP-SMX as prophylaxis against PJP. Other appropriate but less dire measures include giving ganciclovir as prophylaxis against cytomegalovirus (CMV). Patients should be closely monitored to avoid transplant rejection as well as infection.

Weyant et al. review the evidence regarding the treatment of patients with PJP. They discuss how TMP-SMX has been the classic prophylaxis and treatment for this disease. They recommend considering echinocandins for patients who experience significant side effects.

Incorrect Answers:
Answer A: Azithromycin is appropriate prophylaxis for patients with HIV with CD4 counts < 50. Patients on immunosuppressive drugs should receive some of the same prophylactic medications but they do not require azithromycin upon initiation of immunosuppressive medications.

Answer B: Low-dose acyclovir would be an inappropriate intervention in this patient after a transplant procedure. Ganciclovir and high-dose acyclovir are the appropriate options for prophylaxis of CMV.

Answer C: Penicillin can be used as prophylaxis for patients with rheumatic heart disease or asplenia; however, it would not be the most appropriate initial measure in a transplant patient.

Answer E: Valacyclovir is the treatment for herpes simplex virus (HSV). It is not routinely indicated as prophylaxis in transplant patients. HSV will present with vesicular rashes developing on the affected areas.

Bullet Summary:
Patients on immunosuppressive therapy after a transplant should be vaccinated (pneumovax, hepatitis A and B, influenza, and tetanus-diphtheria) and started on TMP-SMX.


Question: An 83-year-old man is brought to the emergency department by his daughter due to confusion over the last 2 weeks. The patient initially became less talkative than usual before starting to confuse her with her sister. The patient also could not remember what day of the week it was and he was out of groceries and likely had been for several days when visited. While she was talking to him, he fell asleep and was difficult to rouse. The patient is unable to provide a clear history. He has a medical history of hypertension, glaucoma, and osteoarthritis in his left knee that requires him to walk with a cane. He takes hydrochlorothiazide, timolol eyedrops, and occasional acetaminophen. His temperature is 98.5° F (36.9° C), blood pressure is 122/74 mmHg, pulse is 75/min, and respirations are 14/min. The patient is lethargic but arousable, oriented only to person, and disheveled. Neurologic exam reveals intact cranial nerves, 1+ deep tendon reflexes throughout, and 4/5 strength in all extremities. There is a 3 x 5 cm green-blue area of ecchymosis on the lateral aspect of his left knee. A CT of the head without contrast is performed and shown in Figure A. Which of the following factors plays the earliest role in the progression towards this patient’s presentation?

Answer: Cerebral atrophy

Explanation:
This patient is an elderly man with progressive confusion over weeks, a nonfocal neurologic exam, and a CT of the head showing a hypodense crescent, most consistent with chronic subdural hematoma (SDH). Cerebral atrophy plays the earliest role in this presentation, resulting in exposure of the bridging veins and subsequent rupture with even minor trauma.

Chronic subdural hematomas present gradually, most often with headaches, somnolence, light-headedness, cognitive impairment, and rarely, seizures. Typically, the neurologic exam is largely normal but rarely focal deficits such as contralateral hemiparesis from compression of the cortex underlying the hematoma or ipsilateral hemiparesis from the lateral displacement of the opposite cortex may occur. Chronic SDH most often occurs in the setting of cerebral atrophy related to increased age, chronic alcohol use, and prior traumatic brain injury. Exposure of the bridging veins allows even minor trauma to precipitate subdural bleeding. A non-contrast CT of the head is indicated in any elderly patient with decreased mentation and concern for chronic SDH. Since old blood appears hypodense, imaging will allow for the determination of whether the bleed is acute or chronic. Supportive care is usually sufficient for treatment but surgical evacuation of the hematoma can be considered in patients with focal deficits or an expanding hematoma.

Mehta et al. review the evidence regarding the diagnosis and management of chronic subdural hematomas in elderly patients. They discuss how crescentic layering of fluid in the subdural space on a non-contrast computed tomography scan is diagnostic of this condition. They recommend close follow-up as many patients will develop a recurrence of this condition.

Figure/Illustration A shows a non-contrast CT scan of the head with a hypodense crescent left side (red circle). This finding is consistent with a chronic subdural hematoma.

Incorrect Answers:
Answer A: Aneurysmal rupture is an extremely uncommon cause of SDH and typically causes subarachnoid hemorrhage instead. It often presents with “the worst headache of my life” or “thunderclap headache,” and would show hyperdensity in the subarachnoid space on head CT. Surgical clipping or endovascular treatment can prevent rebleeding.

Answer C: Elder abuse can be subtle and should always be considered when an elderly patient presents with confusion, bruising, or dishevelment. In children, abuse is an important cause of SDH, which may occur in the setting of “shaken baby syndrome.” However, abuse is not especially associated with chronic SDH in the elderly population, and there is another plausible reason for this patient’s presentation (trauma from a fall as evidenced by the resolving ecchymosis on his knee).

Answer D: Hypertension is a major risk factor for stroke, which typically presents with focal neurologic deficits such as hemiparesis, aphasia, or sensory loss. Although this patient does have a history of hypertension, he is normotensive in the emergency room and has non-focal neurologic decline that has been slowly progressive, which is less consistent with stroke. Furthermore, in contrast to this patient’s CT scan, acute ischemic stroke would likely present with a normal head CT and prior infarct would cause a hypodensity in the parenchyma itself. Treatment is with risk factor optimization when a patient presents outside the window for thrombolytic agents.

Answer E: Increased CSF due to poor reabsorption by arachnoid granules is the cause of normal pressure hydrocephalus (NPH). Patients typically present with the “wet, wacky, and wobbly” triad – urinary incontinence, mental status changes, and magnetic gait. Head CT would show dilated ventricles and management includes CSF shunting.

Bullet Summary:
Chronic subdural hematomas may occur in elderly patients due to cerebral atrophy and subsequent exposure of bridging veins that may tear with minor trauma.


Question:
A 45-year-old African American woman presents to her primary care physician for not feeling well. She states she has had a cough for the past week. She also has abdominal pain and trouble focusing that has been worsening and has lost 5 pounds recently. Her gastroesophageal reflux disease (GERD) has been poorly controlled recently. The patient is a non-smoker and has a history of GERD for which she takes antacids. Her temperature is 98.6°F (37°C), blood pressure is 115/71 mmHg, pulse is 72/min, and respirations are 12/min. A physical exam is within normal limits. Laboratory studies are ordered and are below:

Serum:
Na+: 139 mEq/L
K+: 4.1 mEq/L
Cl-: 101 mEq/L
HCO3-: 24 mEq/L
Urea nitrogen: 12 mg/dL
Glucose: 70 mg/dL
Creatinine: 0.9 mg/dL
Ca2+: 12.5 mg/dL
Alkaline phosphatase: 150 U/L
Phosphorus: 2.0 mg/dL

Urine:
Color: amber
Nitrites: negative
Sodium: 5 mmol/24 hours
Red blood cells: 0/hpf

Which of the following is the most likely explanation of this patient's current presentation?

Answer: Increased parathyroid hormone

Explanation:
This patient is presenting with hypercalcemia and low phosphate levels suggesting a diagnosis of hyperparathyroidism.

Hyperparathyroidism can cause hypercalcemia which typically presents with "bones, stones, moans, and groans," which corresponds to symptoms of bone pain (increased bone resorption), kidney stones, GI pain, and change in mental status/trouble focusing. The increased PTH results in renal phosphate wasting, increased production of 1,25-dihydroxy vitamin D, and increased renal calcium reabsorption. It also results in increased osteoclast activity resulting in increased bone breakdown. This will lead to laboratory changes of hypercalcemia and hypophosphatemia.

Taniegra reviews the evidence regarding hyperparathyroidism. She discusses how this disease is usually discovered asymptomatically with routine blood work. She recommends surgical treatment with intractable cases as success rates are high.

Figure A is a chest radiograph that is within normal limits. No masses are seen which suggests that malignancy is a less likely diagnosis.

Incorrect Answers:
Answer A: Antacid overuse for this patient's GERD can lead to a milk-alkali syndrome which presents with hypercalcemia and metabolic alkalosis. This patient does not have metabolic alkalosis. Treatment is with the discontinuation of the offending agent.

Answer B: Increased 1,25-dihydroxy vitamin D occurs in sarcoidosis which presents with cough, fatigue, and weight loss in an African American woman. Increased vitamin D by itself will result in hypercalcemia, and hyperphosphatemia rather than hypophosphatemia. Treatment is supportive and/or with corticosteroids.

Answer D: Malignancy (lung or renal cancer) is possible given this patient's presentation. Hypercalcemia of malignancy is a common feature with PTH-related protein effects; however, the patient's normal urinalysis and normal chest radiograph as well as non-smoking history point more toward a diagnosis of increased PTH.

Answer E: Viral illness is possible given this patient's systemic symptoms; however, it does not explain this patient's hypercalcemia and hypophosphatemia. Treatment of seasonal viruses is generally supportive though specific viruses such as influenza have agents such as oseltamivir that may be helpful.

Bullet Summary:
Hyperparathyroidism presents with "bones, stones, moans, and groans," as well as laboratory findings of hypercalcemia and hypophosphatemia.


Question: A 57-year-old man is brought to a neurologist by his wife for abnormal behavior. He was normal until around 3 months ago when he started forgetting important meetings and misplacing items around the house. One month ago, the patient was fired from his job as a software engineer after attempting to grope a coworker. The patient expresses frustration that he is no longer able to concentrate enough to enjoy his hobby of solving puzzles. His medical history is significant for gastroesophageal reflux disease for which he takes omeprazole. He has no family history of neurologic disease. His temperature is 98.6°F (37.0°C), blood pressure is 120/75 mmHg, pulse is 70/min, and respirations are 16/min. During the examination, the patient’s cell phone rings unexpectedly causing the patient to suddenly jerk his arms and legs. Further diagnostic investigation is performed which reveals an elevated 14-3-3 protein on cerebrospinal fluid analysis. Which of the following is the most likely diagnosis?

Answer: Creutzfeldt-Jacob disease

Explanation:
This patient with rapidly progressive dementia over 3 months, declining executive function, impaired concentration, decreased memory, startle myoclonus (sudden jerking of extremities in response to unexpected stimulus), and elevated 14-3-3 protein levels on cerebrospinal fluid (CSF) analysis most likely has Creutzfeldt-Jakob disease (CJD).

CJD is a human prion disease in which the normal prion protein (PrPc) converts to a beta-pleated sheet disease-associated form (PrPsc) which is resistant to proteases. CJD is usually spontaneous. Rarely, CJD may be familial or acquired (from iatrogenic transmission or dietary exposure). Aggregates of PrPsc lead to spongiform vacuolation. Clinically, this manifests with rapidly progressive mental deterioration with prominent executive dysfunction (declining concentration, judgment, and memory) and startle myoclonus. Further diagnostic investigation may reveal 14-3-3 protein on CSF analysis and synchronous sharp wave complexes on electroencephalogram (EEG). CJD usually leads to death within 1 year. There is no known effective treatment for this disease.

Uttley et al. review the diagnosis, clinical presentation, and epidemiology of Creutzfeldt-Jakob disease (CJD). They discuss how CJD in a global context is increasing in prevalence and how incubation periods as long as 40 years have been observed for iatrogenic cases. They recommend heightened awareness of this disease in order to mitigate iatrogenic transmission.

Incorrect Answers:
Answer A: Alzheimer disease is characterized by gradual cognitive decline with difficulty completing activities of daily living. Impaired executive function early in the disease course, rapidly progressive disease, elevated 14-3-3 protein on CSF analysis, and startle myoclonus are not found in Alzheimer disease.

Answer C: Lewy body dementia (LBD) presents with alterations in consciousness, disorganized speech, visual hallucinations, extrapyramidal symptoms, and early compromise of executive function. Although this patient’s dementia is characterized by early compromise of executive function, the absence of fluctuating levels of consciousness, absence of extrapyramidal symptoms, and presence of startle myoclonus make CJD more likely than LBD.

Answer D: The behavioral variant of frontotemporal dementia (FTD) is associated with early-onset personality and behavioral changes, and it may be associated with extrapyramidal symptoms. Memory is not usually affected until late in the disease course.

Answer E: Subcortical leukoencephalopathy (Binswanger disease) is a type of small vessel vascular disease that presents with prominent subcortical dementia. This manifests clinically as slowed mental processing, impaired cognition, apathy, and depression. This disease almost always presents in the context of chronic hypertension and is usually seen in older patients.

Bullet Summary:
Creutzfeldt-Jacob disease is a fatal prion disease that presents with sudden-onset and rapidly progressive dementia and startle myoclonus or seizures.


Question: A 24-year-old man presents to the emergency room after a motor vehicle collision. He was the driver in a head-on collision and was not wearing a seatbelt. The patient is acutely intoxicated and is attempting to attack the nurses. Soon after presentation, he is sedated, paralyzed, and intubated. His medical history is unknown. His temperature is 97.6°F (36.4°C), blood pressure is 74/34 mmHg, pulse is 180/min, respirations are 32/min, and oxygen saturation is 98% on room air. Physical exam is notable for jugular venous distension. An electrocardiogram (ECG) is performed as seen in Figure A. Which of the following is the most appropriate next step in management?

Answer: Pericardiocentesis

Explanation:
This patient is presenting after trauma with hypotension, tachycardia, jugular venous distension, and electrical alternans on ECG, which is concerning for cardiac tamponade. The most important initial step in management is pericardiocentesis.

Cardiac tamponade can occur after trauma, infections, or malignancy. It can occur if there is an accumulation of fluid in the pericardial sac with inadequate time for the pericardial sac to stretch and for the heart to adapt to the compression that causes diastolic dysfunction. Patients will present with hypotension, tachycardia, jugular venous distension, muffled heart sounds, and pulsus paradoxus (blood pressure drop > 10 mmHg with inspiration). The diagnosis can be supported with ultrasonography (in the clinical setting a point of care ultrasound will often be performed first); however, the initial step in management is a pericardiocentesis which will stabilize the patient. Subsequent management requires the placement of a pericardial drain or window, as well as treatment of the underlying cause.

Prabhakar et al. discuss pericardial decompression syndrome, an infrequent complication of pericardiocentesis. The authors find that pericardial decompression syndrome presents with paradoxical hemodynamic instability and/or pulmonary edema following pericardiocentesis, especially in patients with underlying myocardial dysfunction. The authors recommend careful monitoring of patients after pericardiocentesis for the development of this complication.

Figure/Illustration A is an ECG demonstrating electrical alternans. Note the alternating large QRS complexes (blue arrows) and small QRS complexes (green arrows) which are suggestive of the heart swinging in a fluid-filled pericardium.

Incorrect Answers:
Answers 1 & 5: Needle thoracostomy followed by tube thoracostomy is the appropriate management of a tension pneumothorax. A tension pneumothorax would also present with hypotension, tachycardia, and jugular venous distension; however, it would not present with muffled heart sounds and electrical alternans on ECG. On exam, there would be an absence of unilateral breath sounds and the presence of tracheal deviation.

Answer B: Packed red blood cells are appropriate management of a hypotensive and tachycardic trauma patient when it is suspected that their unstable vitals are secondary to hemorrhage. In this patient, there is conclusive evidence (jugular venous distension and electrical alternans) that this patient has cardiac tamponade.

Answer C: Pericardial window is the appropriate long-term treatment of recurrent pericardial effusions as it allows for a permanent conduit for the drainage of fluid. An acutely unstable patient should first be stabilized with a pericardiocentesis before going to the operating room for this procedure.

Bullet Summary:
The most important initial step in the management of cardiac tamponade in a hemodynamically unstable patient is pericardiocentesis.


Question: A 68-year-old woman presents to her primary care provider for dizziness. She often feels lightheaded and like she may “pass out” but never actually loses consciousness. She denies dyspnea on exertion or orthopnea. The patient had a myocardial infarction 6 months ago, and she now has multiple drug-eluting stents. Her ECG upon discharge from that hospitalization was normal. The patient has been taking all of her medications as instructed. Her medical history is otherwise significant for rheumatoid arthritis and migraines. Her home medications include methotrexate, atorvastatin, clopidogrel, and aspirin. Her temperature is 98.6°F (37°C), blood pressure is 118/75 mmHg, pulse is 92/min, and respirations are 12/min. On physical exam, she has an irregular heartbeat with normal cardiac sounds. Her abdomen is non-distended and she has mild lower extremity edema. Her current ECG can be seen in Figure A. Which component of the cardiac conduction system is most likely affected in this patient?

Answer: Atrioventricular node

Explanation:
This patient who presents with lightheadedness and is found to have progressive prolongation of the PR interval on ECG most likely has Mobitz type 1 (Wenckebach) 2nd-degree heart block. Mobitz type 1 heart block is usually caused by atrioventricular node dysfunction.

Second degree heart block can be divided into Mobitz type 1 and Mobitz type 2 patterns. The Mobitz type 1 pattern is usually a result of dysfunction at the atrioventricular (AV) node, whereas the Mobitz type 2 pattern is usually caused by dysfunction below the AV node in the His-Purkinje system. In Mobitz type 1 2nd-degree heart block, the PR interval becomes progressively longer with each beat before the dropped QRS complex. In Mobitz type 2 2nd-degree heart block, the PR intervals are consistent in length and the dropped QRS complexes occur at regular intervals. The easiest way to determine whether the PR interval is getting longer is to compare the PR interval just before the dropped beat to the PR interval immediately following the dropped beat. Patients with Mobitz type 1 blocks generally do not require treatment unless symptomatic whereas those with Mobitz type 2 blocks generally require pacemaker placement.

Clark and Prystowsky review the pathophysiology of heart block. They discuss how a type 1 2nd-degree heart block is caused by dysfunction of the atrioventricular node. They recommend symptomatic treatment of this condition.

Figure/Illustration A is an ECG that demonstrates the progressive prolongation of the PR interval (blue lines) until a beat is dropped. This progressive prolongation is characteristically seen in Mobitz type 1 (Wenckebach) heart block.

Incorrect Answers:
Answer B: A bundle branch block would produce a classic right or left bundle branch block pattern on ECG (RSR') described colloquially as "bunny ears." Bundle branch blocks are defined in part by a QRS duration > 120 ms and can be seen in lead V1. Treatment is with control of underlying risk factors such as hypertension.

Answer C: The bundle of His conducts the electrical impulse from the atrioventricular node to the ventricles. Dysfunction at the level of the bundle of His would more likely cause Mobitz type 2 2nd-degree heart block or 3rd-degree heart block rather than the Mobitz type 1 heart block seen in this patient. Treatment is with pacemaker placement.

Answer D: Purkinje fibers rapidly conduct along the ventricular walls to create synchronized contraction of the ventricles. Aberrant conduction of the Purkinje fibers leads to premature ventricular complexes. Treatment is with beta-blockers if patients are symptomatic.

Answer E: The sinoatrial node is the heart’s primary pacemaker. Dysfunction at this level can lead to sick sinus syndrome. Sick sinus syndrome can manifest as many types of arrhythmias, including bradycardia-tachycardia syndrome, in which there is alternating bradycardia with paroxysmal tachycardia. Sinoatrial node dysfunction can be treated with pacemaker placement.

Bullet Summary:
Mobitz type 1 (Wenckebach) 2nd-degree heart block is characterized by progressive prolongation of the PR interval before a dropped QRS complex and is usually caused by dysfunction of the atrioventricular node.


Question:
A 69-year-old man presents to his primary care provider for a general checkup. He has a medical history of type 2 diabetes mellitus, hypertension, depression, obesity, and a myocardial infarction 7 years ago. The patient's prescribed medications are metoprolol, aspirin, lisinopril, hydrochlorothiazide, fluoxetine, metformin, and insulin. The patient has not been filling his prescriptions regularly and can not remember what medications he has been taking. His temperature is 99.5°F (37.5°C), pulse is 96/min, blood pressure is 180/120 mmHg, respirations are 18/min, and oxygen saturation is 97% on room air. Laboratory values are obtained and the results are shown below:

Serum:
Na+: 139 mEq/L
K+: 4.3 mEq/L
Cl-: 100 mEq/L
HCO3-: 24 mEq/L
BUN: 7 mg/dL
Glucose: 170 mg/dL
Creatinine: 1.2 mg/dL

Which of the following cardiac findings would be expected on physical exam?

Answer: Heart sound before S1

Explanation:
This patient who presents with poorly managed hypertension over a long period of time most likely has compensatory hypertrophy of the heart. The most likely heart sound in this patient is an S4 gallop that occurs immediately before S1.

Chronic hypertension that is poorly controlled can lead to concentric hypertrophy of the heart. This adaptive mechanism creates a stiff and non-compliant left ventricle. When blood enters this stiff ventricle, the typical sound heard is an S4 heart sound which is heard right before S1. This sound represents the atrial kick that pushes blood against a non-compliant left ventricle in the last phase of diastole. Treatment is by meticulous control of the underlying cardiac pathophysiology such as hypertension.

Kino et al studied the relationship between the S1 and S4 heart sounds in aging patients. They found that an S4 heart sound can be missed in cases of prominent S1 splitting. They recommend studying heart sounds in order to not accidentally miss an S4 finding.

Incorrect Answers:
Answer A: Fixed splitting of S1 and S2 describes an atrial septal defect. The atrial septic defect allows blood to communicate between both sides of the heart and equalizes atrial pressures. Asymptomatic patients may not need treatment but surgical repair of the defect should be performed in symptomatic cases.

Answer B: A heart sound after S2 suggests a S3 heart sound which would be found in fluid-overloaded states such as heart failure. This post-systolic gallop is the result of incomplete emptying of the ventricle prior to the start of diastole so that the blood from the atria falls against an already full chamber. Treatment is with diuresis and treatment of the underlying heart failure.

Answer D: A holosystolic murmur heard at the apex describes mitral valve regurgitation. This would be possible if a papillary muscle had ruptured in an acute myocardial infarction. Treatment is with mitral valve replacement in symptomatic patients.

Answer E: A normal S1 and S2 is possible but is less likely given this patient's long-standing history of poorly managed hypertension. Hypertension usually causes concentric hypertrophy of the ventricle and thereby leads to increased resistance to diastolic filling.

Bullet Summary:
An S4 heart sound is created by blood entering a stiff and non-compliant left ventricle and is often heard in patients with long-standing hypertension.


Question: A 66-year-old man presents to the clinic with a 6-week history of bloody stools. He describes the blood as bright red wisps that float on the surface of the stool. He has no pain with bowel movements but notes on occasion he may strain. He does not endorse fatigue, fever, constipation, diarrhea, nausea, vomiting, abdominal pain, weight loss, or dyspnea. His last colonoscopy was 3 years prior to presentation and was benign. He has a medical history significant for hypertension that is well-controlled with lisinopril. He had an uncomplicated appendectomy when he was 23 years old. He has no family history of gastrointestinal malignancy. His temperature is 98.6°F (37.0°C), blood pressure is 140/90 mmHg, pulse is 76/min, and respirations are 16/min. On physical exam, the patient's abdomen is soft, non-distended, and non-tender with normal bowel sounds and without organomegaly or masses. The anus is patent without fissures, hemorrhoids, or skin tags. Which of the following is the most appropriate next step in management?

Computerized tomography scan of abdomen and pelvis

Answer: Colonoscopy

Explanation:
This patient is presenting with painless bright red blood per rectum. Because he is over 50 years old and having rectal bleeding, he should be evaluated for malignancy with a colonoscopy.

Bright red blood per rectum has a broad differential diagnosis including anal fissures, hemorrhoids, angiodysplasia, inflammatory bowel disease, diverticular bleed, infection, polyps, and colon cancer. However, as patients age, their risk for malignancy increases significantly. Therefore, stable patients older than 50 years of age with rectal bleeding, regardless of their symptoms or family history, should receive a colonoscopy to rule out malignancy. Patients younger than 50 with warning signs of colon cancer (abnormal bowel habits, weight loss, family history of colon cancer, iron deficiency anemia) should also be evaluated with a colonoscopy. Often, colonoscopy is performed routinely at the age of 50 or 10 years prior to the age of presentation for malignancy in family members (whichever is sooner). Of note, even if there is an apparent cause for a lower GI bleed in patients 50 or older (such as hemorrhoids) colonoscopy is still indicated to rule out malignancy.

Barry et al. note the guidelines for colon cancer screening. They note the different age cutoffs. The USPSTF recommends screening for colorectal cancer in all adults aged 50-75 years.

Incorrect Answers:
Answer B: Computerized tomography scan of the abdomen and pelvis is incorrect because colonoscopy is the gold standard for diagnosis of suspected colon cancer. A CT scan may detect larger masses and a CTA may be performed if there is active bleeding and concern for an arterial source of bleeding that can be intervened upon.

Answer C: Increasing fiber in the diet may help patients with constipation or hemorrhoidal bleeding. Constipation presents with straining to have bowel movements and hard stools. However, because of this patient's age, he needs a colonoscopy to rule out malignancy.

Answer D: Observation is not appropriate at this patient's age. Patients greater than 50 years old with bright red blood per rectum should receive a colonoscopy to rule out malignancy despite any recent negative colonoscopy results.

Answer E: Sigmoidoscopy is less preferred to colonoscopy, as a smaller portion of the colon would be visualized, and colonic polyps or malignancies may be missed. For this reason, it is not the preferred study in this patient.

Bullet Summary:
Patients with bright red bleeding per rectum over 50 years old or with warning signs of colonic malignancy (weight loss, abnormal bowel habits, positive family history, or anemia) should receive a colonoscopy.


Question: A 6-week-old girl presents with her parents to the pediatrician for blood-streaked diapers. The patient is breastfed every 2-3 hours and voids 10-12 times daily. The patient previously had several soft stools per day that ranged in color from mustard yellow to dark green. Over the past 2 days, the patient’s stools have become looser and streaked with blood. The patient has also regurgitated several of her feedings in the last few days. Neither the vomit nor bloody stools have seemed to bother the patient. The patient’s weight continues to trend along the 50th percentile. The patient’s temperature is 98.4°F (36.9°C), blood pressure is 66/51 mmHg, pulse is 127/min, and respirations are 26/min. On physical exam, the patient appears well nourished and is cooing. Her abdomen is soft and non-tender. Physical exam reveals the finding seen in Figure A. Which of the following is the most likely etiology of this patient’s presentation?

Passage of gastric contents into esophagus

Answer: Non-IgE-mediated immunologic reaction

Explanation:
This patient presents with new regurgitation, blood-streaked stools, and eczema, which is consistent with proctocolitis secondary to milk-protein allergy. This type of delayed onset milk-protein allergy is a non-IgE mediated immunologic reaction.

Allergy to cow’s milk is the most common food allergy in children and encompasses both IgE-mediated and non-IgE-mediated reactions. IgE-mediated reactions occur minutes to 2 hours after ingestion of the allergen and range from mild symptoms to anaphylaxis. Milk protein-induced enterocolitis and proctocolitis are non-IgE-mediated reactions that present by 6 months of life with regurgitation or vomiting and bloody stools. Management of milk protein-induced enterocolitis and proctocolitis involves the elimination of cow’s milk and soy from the mother’s diet if the infant is breastfed or switching to a hydrolyzed formula if the infant is formula fed.

Giannetti et al. review the evidence regarding the diagnosis and treatment of milk protein allergy in infants. They discuss how the selective elimination of certain proteins from the diet is usually effective. They recommend considering oral immunotherapy as an adjuvant in the treatment of this disease.

Figure/Illustration A is a clinical photograph demonstrating the physical exam finding of eczema (red circle), which is commonly found in infants with an allergy to milk protein.

Incorrect Answers:
Answer A: Congenital enzyme deficiency describes lactose intolerance, in which there is an absence of lactase activity in the small intestine. Lactose intolerance classically presents with abdominal pain, bloating, flatulence, and diarrhea. Treatment is with diet modification.

Answer C: Hypertrophy of the sphincter muscle describes the pathogenesis of pyloric stenosis, which presents in patients between 3- and 6-weeks of age with non-bilious, projectile vomiting. Treatment is with surgical pyloromyotomy.

Answer D: Passage of gastric contents into the esophagus describes gastroesophageal reflux, which may present with regurgitation or vomiting. Treatment is with positioning but can include proton pump inhibitors in refractory cases.

Answer E: Telescoping of the intestine describes intussusception, which presents with sudden-onset severe, crampy, abdominal pain with non-bilious vomiting and “currant jelly” stools. Intussusception is rare before 3 months of age and presents with intermittent episodes of pain. Initial treatment is with air or contrast enema.

Bullet Summary:
Milk-protein allergy presents in infants between 2- to 8-weeks of age with regurgitation or vomiting, blood-streaked stools, and eczema, and management involves the elimination of cow’s milk and soy from the infant’s diet.


Question: A 22-year-old man presents to the emergency department with difficulty breathing. He has experienced similar symptoms before. Today, he was hit in the face with a football, followed by significant swelling of his lips and tongue. The patient speaks with a muffled voice. His temperature is 98.1°F (36.7°C), blood pressure is 120/83 mmHg, pulse is 80/min, respirations are 16/min, and oxygen saturation is 98% on room air. Physical exam reveals swollen lips and a protruding, enlarged tongue. His breath sounds are clear. He demonstrates no rash and his abdomen is soft and nontender. Which of the following is the most effective therapy for this patient?

Answer: Fresh frozen plasma

Explanation:
This patient is presenting with recurrent episodes of significant swelling of his lips and tongue with minor trauma, which are concerning for hereditary angioedema. Fresh frozen plasma is the most effective therapy for hereditary angioedema of the options listed.

Angioedema is a potentially life-threatening condition that presents with severe edema of the gastrointestinal and respiratory tracts. It can be caused by antigens, medications, and trauma or may occur spontaneously. It often presents with notable edema of the lips and tongue and may threaten the airway. There are 3 subtypes. Hereditary and acquired angioedema occur secondary to a deficiency of C1-esterase inhibitor. As a result, the most effective therapy is to administer fresh frozen plasma which has C1-esterase inhibitor. On the other hand, drug-induced angioedema (often from angiotensin-converting enzyme inhibitors and angiotensin receptor blockers) does not respond well to C1-esterase inhibitor replacement and supportive therapy; discontinuing the offending agent is the mainstay of therapy. Other effective but costly treatments that can be used in hereditary angioedema include: icatibant, ecallantide, and C1 inhibitor.

Paige and Anderson note the management of hereditary angioedema. They review the different treatments and discuss C1-esterase inhibitor replacement. They recommend this treatment for acute episodes.

Incorrect Answers:
Answer A: Dexamethasone and other steroids can be given in acute allergic reactions and may reduce the recurrence of symptoms but are unlikely to be effective in angioedema, nor are they the most effective therapy. Steroids can take up to 4 hours to begin having any effect.

Answer B: Diphenhydramine is an antihistamine that could be given for anaphylaxis or urticaria and works immediately; however, it is not the mainstay of therapy for angioedema nor is it the most effective therapy. It is the mainstay of therapy for urticaria. It can also be given in anaphylaxis.

Answer C: Epinephrine is the treatment of choice for anaphylaxis which presents with urticaria, upper airway swelling, hypotension, nausea/vomiting, and wheezing. It is often given in angioedema but has limited efficacy when compared to fresh frozen plasma.

Answer E: Tranexamic acid is effective in treating angioedema and current evidence supports its use; however, the mainstay of therapy is still fresh frozen plasma. Tranexamic acid is also used in hemorrhagic shock to stop fibrinolysis and reduce bleeding.

Bullet Summary:
A possible treatment in hereditary or acquired angioedema is the administration of fresh frozen plasma to replace C1-esterase inhibitor.