Azathioprine Hypersensitivity in Bullous Pemphigoid

In July 1990, a 65-year-old woman with bullous pemphigoid exhibited azathioprine hypersensitivity, characterized by fever, chills, malaise, headaches, and blurred vision, which occurred after the ingestion of the drug. The symptoms resolved within 24 hours of discontinuing azathioprine and recurred upon rechallenge, confirming the hypersensitivity. The patient was successfully treated with niacinamide and topical betamethasone dipropionate ointment without further development of bullae. This case underscored the need for careful drug reaction monitoring, particularly in elderly patients on multiple medications, as this specific reaction to azathioprine had not been previously documented.