Case for diagnosis
A 63-year-old Caucasian man presented with a two-month history of an intensely pruritic,\nsymmetric and polymorphous skin eruption. His past medical history was unremarkable.\nOn examination, we observed multiple papules, vesicles, pustules and crusted\nexcoriations on an erythematous base, especially over the buttocks, legs and arms (). The oral and genital mucosas were spared.\nNikolsky's sign was negative.\nTzanck smear showed abundant eosinophils with absence of acantholytic cells.\nHistopathological examination revealed eosinophilic spongiosis and intraepidermal\nvesicles filled with eosinophils and neutrophils (). Direct immunofluorescence microscopy showed intercellular deposits of IgG\n(). High titers of circulating\nanti-desmoglein 1 autoantibodies were demonstrated by immunoblot study. The remaining\nworkup, which included blood tests, imagiologic studies and gastrointestinal endoscopy,\nwas normal.\nThe patient was treated with 100 mg/day dapsone and showed an excellent response. After\na year, he was free of the disease on a maintenance dose of 50 mg dapsone daily.