A 45-year-old man presents to the dermatologist with a complaint of widespread severe itching that occurs around the clock. The itching has persisted for months despite the following treatments: multiple topical steroid preparations; 2-week course of oral prednisone; triamcinolone 40-mg intramuscular injection; oral antihistamines, including hydroxyzine; and 3 separate courses of treatment with permethrin lotion. The permethrin lotion results in short-lived modest relief at best. All other treatments are ineffective.
The patient had a recent physical examination as well as bloodwork without notable findings. His past medical history is likewise unremarkable. The patient’s job often requires him to visit homes with children present.
The patient lives with his wife and 2 children, none of whom have itching or rash. The patient finally agrees to see a dermatologist; his wife is losing sleep because of his restlessness at bedtime.
The patient’s trunk is covered front and back by a barely perceptible fine papulosquamous rash, which runs from his mid-chest and stops at his waistline (Figure 1). Inspection of his hands and wrists reveals no notable changes. Three 3- to 4-mm edematous pruritic pink papules are seen on his penile glans and distal shaft (Figure 2).