Although there is no sure pharmacologic antidote for itching, topically applied itch suppressants have reached an $11 million annual sales volume. In addition, much of the nearly $100 million spent yearly for topical corticosteroids goes to relieve itchy disorders, says James H. Herndon, Jr, MD, of the University of Texas Southwestern Medical School, Dallas.
Speaking at the annual American Academy of Dermatology meeting, Herndon said that pruritus may be a problem for patients with any of a number of systemic illnesses, such as for half or more of the approximately 30,000 persons receiving regular hemodialysis or about one third of patients with Hodgkin's disease. He noted that patients with polycythemia vera and other hyperplastic myeloid states also may have severe itching, particularly following a hot bath or consumption of alcohol.
Classic studies in the literature indicate that between 20% and 30% of patients with primary pruritus have an underlying disease.