Chronic Pruritus

An otherwise healthy 55-year-old man reports that he has been itchy all over for 6 months. The itch interferes with falling asleep and wakes him repeatedly during the night. Initially, there was no rash, but during the past 4 months, itchy nodules and plaques have developed on his back, arms, and legs. Treatment with sedating and nonsedating oral antihistamines and topical glucocorticoids has had no effect. How would you evaluate and manage this case?