HIVES

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Hives on the Back

Hives is an itchy rash.
The shapes of hives are variable. Sizes of hives vary from ½ inch to several inches across.
Hives may disappear in one area and then reappear somewhere else, over the course of several hours.

Hives on the Abdomen

Hives is an itchy rash.
The shapes of hives are variable. Sizes of hives vary from ½ inch to several inches across.
Hives may disappear in one area and then reappear somewhere else, over the course of several hours.

Symptom Definition

Itchy swollen patches that appear suddenly
Location, size, and shape of patches change rapidly and repeatedly, with any one patch lasting from several minutes to several hours.
Size of patches varies from a 1/2 inch to several inches across.
In Caucasians, hives appear pink or red in color, with a central area of paleness

General Information

The medical term for hives is "urticaria".
Hives are sometimes an allergic skin reaction to something that the individual has eaten, touched, or in some other manner been exposed to.
Hives usually come and go for several days to a week. Sometimes they can reappear weeks or months later. Some individuals have "chronic urticaria," which means that the rash can be intermittently present for months.

Definitions

Anaphylaxis: A life-threatening type of allergic reaction.
Localized Hives: Hives on one area of the body only. Localized hives are usually due to skin contact with plants, pollen, food, a chemical, or pet saliva. Localized hives usually resolve in less than 4 hours.
Widespread Hives: Hives on multiple (2 or more) areas of the body. Widespread hives can be an allergic reaction to a food, cosmetic product, drug, insect bite, or other substance. Sometimes widespread hives show up after a viral infection. Often the cause is not found.

See More Appropriate Topic (instead of this one) If

Rash doesn't look like hives, see RASHES WIDESPREAD AND CAUSE UNKNOWN
It's probably mosquito bites, see INSECT BITES

Disclaimer: This information is not intended be a substitute for professional medical advice. It is provided for educational purposes only. You assume full responsibility for how you choose to use this information.

Reviewed 8/2004

Revised 8/2003

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