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Symptoms and Signs of Hives and Angioedema

Doctor's Notes on Hives and Angioedema

Hives and angioedema are reactions of the skin to histamine and other chemicals. Often, the release of these substances is due to an allergic reaction. However, there are many causes of hives and angioedema. Often, the specific cause cannot be determined, and the condition is termed idiopathic. Idiopathic hives and angioedema are very common. Common triggers of both hives and angioedema include infections, allergies, insect bites or stings, and blood transfusions.

Hives (medically known as urticaria) appear as wheals on the skin wheals that are smoothly elevated, red, very itchy patches of skin that often have a blanched center. Hives may be a few millimeters to several centimeters in diameter anywhere on the body and often form welts. Hives typically come one up suddenly often in several places. They may go away after a few hours and appear in another location on the body. Angioedema is like hives, only the welts are larger and form deeper in the skin, leading to severe swelling, usually in the face, near the eyes and mouth.

Medical Author:
Medically Reviewed on 3/11/2019


Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.