immune disorders
Angioedema
Introduction
Angioedema is swelling of areas of tissue under the skin, sometimes affecting the face and throat. Angioedema can be a reaction to a drug or other substance (trigger), a hereditary disorder, a rare complication of cancer, or an immune disorder, but sometimes the cause is not known. Angioedema may involve swelling in the face, throat, digestive tract, and airways. Antihistamines can relieve mild symptoms, but if angioedema makes swallowing or breathing difficult, prompt emergency treatment is needed. (See also Overview of Allergic Reactions .) Angioedema often occurs with Hives , which are small, red, itchy, slightly elevated areas of swelling, often with a pale center. Both hives and angioedema involve swelling, but in angioedema, the swelling is deeper (under the skin) than it is with hives, and it may not itch. There are rare Hereditary and Acquired Angioedema . These forms are caused by a deficiency or malfunction of a substance called C1 inhibitor, which is part of the immune system. Hereditary angioedema and acquired angioedema resemble angioedema caused by an allergic reaction. However, hives do not develop, and the cause is different. Angioedema may be acute or chronic. 