What are hives?
Hives are red, very itchy, swollen areas of the skin. They arise suddenly and may leave quickly, (in 1-2 hours), last for as long as 24 hours, or persist for months. They often appear in clusters. New clusters may appear as old ones fade. Doctors refer to hives as urticaria. Swelling deeper in the skin that may go with hives is called angioedema. This may be seen on the mucous membranes, lips, and eyelids. This is often a result of an allergic reaction.
Hives is a condition that affects many people. At some point in their lives 2 out of 10 people suffer an outbreak of hives.
What causes hives?
The cause of most of the chronic cases of hives is unknown. Allergic and non-allergic causes can produce hives. A reaction to foods or drugs is sometimes the cause. Foods that are known to cause more problems are nuts, tomatoes, and shellfish. Common drugs that could be causes are penicillin, sulfa, seizure medicines, and aspirin. In rare cases, a viral infection or underlying disease may be the cause. Some hives are caused by stroking of the skin or tight fitting clothing. Sunlight or a sun lamp can also cause hives. Blood and urine samples may be taken to screen for rare problems.
Will they go away?
For most patients, hives will disappear as mysteriously as they appeared. Sometimes they fade within hours, only to return later. At times, hives may last for months. If needed, your doctor can prescribe antihistamines. These are medicines that relieve itching and cause the hives to fade away.
Avoid the cause of the hives if it is known. Antihistamines may be prescribed. Some medicines that do not make people sleepy are Claritin® (loratadine) and Allegra® (fexofenadine). Antihistamines such as Zyrtec® (cetrizine), Atarax® (hydroxyzine), and Benadryl® (diphenhydramine), also treat the itching and allow hives to fade. Other medicines may be prescribed. Your doctor will discuss the options with you.
Call your Doctor Right Away If You Have Hives and You
- Have trouble breathing or swallowing.
- Feel dizzy or shaky.
- Have stomach pain or cramps or nausea.
The Spanish version of this Health Facts for You is #7125.
The information provided 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. Any duplication or distribution of the information contained herein is strictly prohibited.
Last Updated: 01/16/2013
Copyright © 01/16/2013 University of Wisconsin Hospitals and Clinics Authority. All rights reserved. Produced by the Department of Nursing. HF#4202
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