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Hives

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Definition:

Hives are raised, often itchy, red welts on the surface of the skin. They are usually an allergic reaction to food or medicine.

Alternative Names:

Urticaria

Causes, incidence, and risk factors:

When you have an allergic reaction to a substance, histamine and other chemicals are released into your bloodstream, causing itching, swelling, and other symptoms. Hives are a common reaction, especially in people with other allergies like hay fever.

When swelling or welts occur around the face, especially the lips and eyes, it is called angioedema . Swelling from angioedema can also occur around your hands, feet, and throat.

Many substances can trigger hives:

• Medications
• Shellfish, fish, nuts, eggs, milk, and other foods
• Pollen
• Animal dander (especially cats)
• Insect bites

Hives may also develop from:

• Infections like mononucleosis or illness (including lupus, other autoimmune diseases , and leukemia)
• Emotional stress
• Extreme cold or sun exposure
• Excessive perspiration

References:

Adkinson NF Jr. Middleton’s Allergy: Principles and Practice . 6th ed. Philadelphia, Pa: Mosby; 2003.

Behrman RE. Nelson Textbook of Pediatrics. 17th ed. Philadelphia, Pa: WB Saunders; 2004.

Habif TP. Clinical Dermatology . 4th ed. St. Louis, Mo: Mosby; 2004.

• Review Date: 4/12/2007
• Reviewed By: Kevin Berman, MD, PhD, Associate, Atlanta Center for Dermatologic Disease, Atlanta, GA. Review provided by VeriMed Healthcare Network.

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