Angioedema

A type of reaction caused by allergy. Angioedema is characterized by large, well-defined swellings, of sudden onset, in the skin, larynx (voicebox), and other areas. The most common cause is a sudden allergic reaction to a food. Less commonly, it results from allergy to a drug (such as penicillin), a reaction to an insect bite or sting, or from infection, emotional stress, or exposure to animals, moulds, pollens, or cold conditions. There is also a hereditary form of the disease. Angioedema may cause sudden difficulty in breathing, swallowing, and speaking, accompanied by swelling of the lips, face, and neck, depending on the area of the body affected. Angioedema that affects the throat and the larynx is potentially life-threatening because the swelling can block the airway, causing asphyxia. Severe cases are treated with injections of adrenaline (epinephrine) and may require intubation (passage of a breathing tube via the mouth into the windpipe) or tracheostomy (surgical creation of a hole in the windpipe) to prevent suffocation. Corticosteroid drugs may also be given. In less severe cases, antihistamine drugs may relieve symptoms.