Bullous pemphigoid possibly induced by psoralen plus ultraviolet A therapy

An elderly white man with a long history of psoriasis, previously treated with topical steroids and ultraviolet B (UVB), developed bullous pemphigoid shortly after starting psoralen plus UVA (PUVA) therapy. The eruption spread from the forearms to the arms and neck after phototherapy was discontinued. The clinical features of the 12 reported cases of PUVA-induced bullous pemphigoid are reviewed.