A Japanese man in his 50s presented with a 6-month history of worsening pruritic hand dermatitis that progressed to involve his face, trunk, upper extremities, and feet. He had emigrated from Japan more than 10 years earlier but had no history of recent travel. He took no medications, had no significant medical or surgical history, and denied personal and family history of atopy. While he worked as a biomedical researcher, he denied any caustic exposures. On physical examination, his face, trunk, upper extremities, palms, and soles were marked by 1-to 2-mm erythematous papules and pustules coalescing into large, partially indurated and polycyclic plaques with centrifugal extension and occasional central clearing (Figure, A and B). Treatment with potent topical corticosteroids was ineffective. Punch biopsies of lesions on the shoulder (Figure, C) and foot (Figure, D) were performed. Diagnosis C. Eosinophilic pustular folliculitis (EPF)