A previously healthy man in his 40s presented with 4 days of fever and a rash. He noticed multiple acneiform papules and pustules around the neckline that progressed to involve the face, torso, and limbs. He took no prescribed medications but had taken an ibuprofen pill a week prior for a mild headache; his symptoms started 3 days after that. He had no sick contacts or recent travel and reported no use of alcohol or tobacco.On examination, he was febrile (38.9°C) and tachycardic but normotensive. Clusters of pustules, approximately 1 mm in diameter, were present over an erythematous base overlying the face, neck, chest, back, and arms (Figure). Laboratory analysis revealed values within normal ranges for hemoglobin (13.1 g/dL) and platelet count (186 ×10 9 /L); an elevated white blood cell count (22.3 x10 9 /L; 82% neutrophils, 9% lymphocytes, 5% eosinophils, 4% monocytes); erythrocyte sedimentation rate of 58 mm/h (reference range, 0-20); C-reactive protein level of 232 mg/L (2210 nmol/L) (reference, <5 mg/dL [48 nmol/L]); and normal renal and hepatic function. Gram stain of the pustule fluid revealed no organisms, and cultures of the blood and pustule fluid were without growth. A punch biopsy of the skin lesions showed subcorneal pustules containing neutrophils and eosinophils, with epidermal spongiosis. Figure. Face, neck, and chest of the patient. WHAT WOULD YOU DO NEXT? A. Avoid further ibuprofen use and prescribe a topical steroid B. Initiate infliximab therapy C. Initiate oral cephalexin therapy D. Obtain a human immunodeficiency virus immunoassay Clinical Review & Education JAMA Clinical Challenge