Hives are a common skin condition that trigger inflammation and itchy raised areas known as wheals. The itching is intense and often distracting.
They typically occur when you're exposed to certain foods, drugs, insect bites, plants, metals, or other allergens. This exposure causes special cells in your body to start releasing histamine, making blood vessels leak fluid into the deepest layers of your skin.
Yet allergic reactions aren't the only cause of hives. Emotional stress, cold weather, even sunshine can trigger them. The wheals may disappear in minutes or hours, but usually within a couple of days. While you wait for them to disappear, follow these tips to relieve the itch and swelling.
Hives can kill by blocking breathing passages. If you get hives in your mouth or throat, call your emergency number (911 in most areas) immediately. If you know that you're subject to this kind of reaction, you should be under a doctor's care and have a readily available supply of epinephrine. This life-threatening allergic reaction, called anaphylaxis, causes several symptoms, usually immediately or within 2 hours of exposure to the offending substance.
Symptoms of anaphylaxis include hives; a sense of uneasiness; agitation; tingling, itchy, and flushed skin; coughing; sneezing; and difficulty breathing as the windpipe swells and closes off. Your heart may malfunction and beat erratically. You may also go into shock.
People with chronic hives (longer than 6 weeks) or with severe acute hives should also see a doctor.
Leonard Grayson, M.D., was formerly clinical associate allergist and dermatologist at Southern Illinois University School of Medicine in Springfield.
Jerome Z. Litt, M.D., is a dermatologist and assistant clinical professor of dermatology at Case Western Reserve University School of Medicine in Cleveland. He is the author of Your Skin: From Acne to Zits and Drug Eruption Reference Manual, a yearly manual now in its fifteenth edition, that catalogues all the rashes you can get from more than 1,000 drugs.
Thomas Squier is a Cherokee herbologist and grandson of a medicine man.