Persistent pruritic, papular truncal rash in an adult

From In ic m D M M Fund A 55-year-old man presented with a pruritic rash on the chest and abdomen that had been present for 6 months. It waxed and waned but never cleared completely. His medications included hydrochlorothiazide 50 mg daily for elevated blood pressure and aspirin 150 mg daily. The physical examination revealed 20 pruritic, erythematous papules ranging from 0.5 mm to 1.0 mm in diameter, surmounted by a hard scale, scattered on the chest and back (Fig 1). Treatment with ketoconazole 2% shampoo overnight three times a week, permethrin 5% cream overnight twice a week, and moisturizing lotions twice daily proved ineffective. A 4-mm punch biopsy specimen was obtained (Figs 2 and 3).