Pemphigus foliaceus resembling eruptive seborrheic keratoses

A 78-year-old man had an acute eruption of lesions that clinically resembled seborrheic keratoses. Microscopic examination of the lesions indicated acantholysis and dyskeratosis primarily in the granular layer. The patient's serum contained antibodies to intercellular substance. Direct immunofluorescence microscopy of a lesion demonstrated immunoglobulin deposition in the intercellular areas. Treatment with oral prednisone produced rapid resolution of the lesions. Patients in whom eruptive seborrheic keratoses (Leser-Trélat sign) develop should have histological examination of their lesions to rule out the diagnosis of pemphigus foliaceus.