What causes the skin to itch?
If only all itches came once every seven years. . . . But almost everyone itches occasionally, and some people itch almost constantly. Itching is notorious as the most common symptom of allergies, says Glenn Kline, M.D., an allergist and assistant clinical professor of pediatrics at the University of Texas at Houston. Very often, itching is a solitary symptom of allergy—at first. Only the “itchee” knows it’s there because it’s invisible. But scratching an allergic itch will often awaken a rash or hives. “The really tough cases are patients who are chronically itchy but have absolutely nothing to see on the skin,” says Ivor Caro, M.D., a dermatologist and associate professor of medicine at the University of Washington School of Medicine in Seattle. That’s when doctors start sleuthing for possible internal causes for this maddening type of itch, such as stress or overproduction of certain hormones. Other common causes of itches: insect bites and stings, parasites, such as chiggers and sc
The exact cause of the itching or pruritus is unknown. Itching is often particularly severe in patients with erythroderma (red skin). The itching can be extremely difficult to control. The best way to control the itching is to achieve a remission of the underlying disease. Antihistamines, particularly Benadryl or Atarax, may provide symptomatic relief from itching. The major side-effect of these antihistamines is drowsiness. Since a tolerance to antihistamines frequently develops, larger doses of these antihistamines can be taken in instances when the itching is not relieved and there is no drowsiness.
