A NONSCARRING SUBLAMINA DENSA BULLOUS DRUG ERUPTION

The term bullous drug eruption connotes several heterogeneous diseases in which blisters occur as a complication of the administration of dr ugs. Blisters may occur in bullous erythema multiforme, fixed drug eru ption, or severe dermatitis medicamentosa with blisters. The common de nominator is thought to be a hypersensitivity reaction to a systemic m edication. Nevertheless, little has been written about the blisters in these disorders, and neither common nor distinct pathogenic mechanism s have been proposed. We describe a patient who had a rapidly progress ive bullous eruption that occurred within hours of receiving intraveno us trimethoprim-sulfamethoxazole. Routine histologic study of lesional skin demonstrated subepidermal blisters. Transmission electron micros copy and immunomapping of various basement components revealed that th e cleavage plane of the blister was well below the lamina densa. After healing of the blistering process, no scarring or milia formation was observed.