wheal and flare reaction


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wheal

 [hwēl]
a localized area of edema on the body surface, often with severe itching but usually of brief duration; it is the typical lesion of urticaria.
wheal and erythema reaction (wheal and flare reaction) the characteristic local cutaneous reaction consisting of an elevated, blanched wheal surrounded by a spreading “flare” of erythema that occurs within a few minutes at the site of a minor nonpenetrating skin injury and also in response to administration of allergen to an atopic individual; it is caused by release of histamine from mast cells.

wheal and flare reaction

The response within 10 to 15 min to an antigen injected into the skin. The injected skin elevates and blanches, and becomes surrounded by a red rim of inflamed tissue.
References in periodicals archive ?
At this point the dogs produce antigen-specific IgE, respond with wheal and flare reactions in skin tests, and show signs of gastrointestinal edema and inflammation.