MedlinePlus Medical Encyclopedia: Hives

Skip navigation

Medical Encyclopedia

Hives

Hives are raised red welts of various size on the surface of the skin, often itchy, which come and go. Also called urticaria, hives is usually part of an allergic reaction to drugs or food. The term "dermatitis" describes an inflammatory response of the skin, caused by contact with allergens or irritants, exposure to sunlight, or by poor circulation, even stress. AVOID SCRATCHING. Scratching the rash may spread the inflammation, lead to infection and even leave scars.

Update Date: 7/19/2007

Updated by: Donald Accetta, MD, MPH, President, Allergy & Asthma Care, PC, Taunton, MA. Review provided by VeriMed Healthcare Network.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 1997-2008, A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.