Stevens-Johnson syndrome: report on a case with a strange complaint of allergy to bus.

Stevens-Johnson syndrome is an uncommon inflammatory skin disorder in which immune mechanisms, cytotoxic reactions, and delayed hypersensitivity seem to be involved. Herein, an unusual case with strange complaint of"bus allergy" is presented, suffering from severe generalized itching and skin lesions, followed by ulcers in his mouth and genitalia. The diagnosis of Stevens-Johnson syndrome was made and appropriate treatment was advised. However, detailed medical history revealed a completely different cause of his allergic reactions, as he had occasionally used dimenhydrinate because of motion sickness in his history. Therefore, adverse drug reaction to dimenhydrinate was considered as the main underlying cause of the disease. In conclusion, thorough medical history should be taken to make a definitive diagnosis and identify the underlying disease, since accurate diagnosis and appropriate treatment can prevent further complications.