Occurrence of bullous pemphigoid after furosemide therapy.

A 78-year-old woman with Parkinson disease developed tense bullous lesions on the chest, arms, and in the groin that were diagnosed as bullous pemphigoid. Histologic examination, as well as immunofluorescence tests, confirmed this diagnosis. The possibility of a drug-induced disease was considered because she was taking seven different medications. Furosemide (Lasix) was suspected primarily. Complete clearing occurred with prednisone therapy, but readministration of furosemide resulted in bulla formation.