A 23-year-old woman was admitted to the Department of Dermatology 4 days postpartum with multiple disseminated pustules. A week earlier, she had received 500 mg of amoxicillin with 125 mg clavulanic acid for pharyngitis. After three doses, she noticed the first pustules appear on the chest and back, and the antibiotic treatment was discontinued. Three days later, during the 37th gestational week, she delivered her second child prematurely, but in generally good condition. After delivery, her skin lesions began to spread, and the patient developed fever up to 39 degrees C (102.2 degrees F). Her medical history was significant for similar pustular lesions at age five, diagnosed as a bacterial skin infection despite negative skin cultures. Antibiotics were introduced with no clinical improvement over several months. Her skin lesions resolved after discontinuation of antibiotics. No personal or family history of psoriasis was present. On admission, generalized pustules and flaccid blisters with pus on an erythematous background were present (Figure 1). The patient complained of burning of the skin lesions and fever (38.2 degrees C [100.8 degrees F]) but was otherwise in good condition. Laboratory tests revealed leukocytosis (15,000/mL) with granulocytosis (82%) and an extremely high C-reactive protein level (323.4 mg/L; normal range, 0-7 mg/L). Bacteriologic culture of the pus was negative. The histopathology revealed a subcorneal blister filled with neutrophils and a few epidermal cells. In the dermis, a scant perivascular inflammatory cell infiltrate was noted (Figure 2). Direct immunofluorescence revealed small amounts of IgM at the dermoepidermal junction. Because of the very diffuse distribution of pustules, two doses of hydrocortisone 200 mg IV b.i.d. for 2 days was administered, followed by prednisone 40 mg q.d. with rapid tapering. Rapid improvement of skin lesions was observed and the patient's skin practically cleared within 7 days. Corticosteroids were discontinued after 14 days.