original: They manifest with either neurological complications or with skin problems (or occasionally both).
simplifications: They show either brain or skin problems (or both). They show up with neurological complications or with skin problems. They show up with neurological issues or skin problems. Though, occasionally both. They have neurological complications or with skin problems. Sometimes they have both. They appear with neurological complications or skin problems (sometimes both). They show up with either brain problems or with skin problems, sometimes both. They manifest with either neurological complications or with skin problems. Occasionally they manifest with both. They become known with either neurological complications or skin problems or both. They show with neurological issues or with skin problems (or occasionally both). They manifest either with neurological damage or with skin problems (or occasionally with both).