Angioedema is a condition in which small blood vessels leak fluid into the deep dermal, subcutaneous and/or submucosal tissue, causing swelling. The swelling usually occurs around the face, lips and tongue but can also affect the throat, hands, feet and genital area. Angioedema can occasionally cause internal swelling of the oesophagus or stomach.
Angioedema can occur with or without the presence of hives (itchy weal-like swellings on the surface of the skin). Usually if the cause is allergy related, angioedema and hives will occur simultaneously. However allergy is a very rare cause of angioedema.
Angioedema is most frequently related to the administration of ace (angiotensin converting enzyme) inhibitor blood pressure medications, however can also be triggered by food or drug allergies, infection or illness, autoimmune disorders, and hereditary factors. Contact allergies, animal allergies and insect stings can sometimes cause swelling which resembles angioedema.
An episode of angioedema typically lasts between one and three days, however can persist for weeks. Allergy-induced angioedema may be suspected if the swelling is rapid in onset but resolves within 24 hours. Swelling which persists for days or weeks is rarely caused by allergy. Exposure to temperature extremes, hormonal changes, emotional stress, medications (such as aspirin) and dietary factors can exacerbate angioedema.
Angioedema is not usually dangerous, and in general, most mild to moderate symptoms can be sufficiently treated with anti-inflammatory medications. Severe swelling of the throat or tongue is a medical emergency owing to the risk for breathing difficulties and airway obstruction. Individuals should seek immediate medical attention.
Australasian Society of Clinical Immunology and Asthma [ASCIA]. 2010. Angioedema. ASCIA Education Resources (AED) Patient Information. Accessed 31 July, 2015, http://www.allergy.org.au/images/stories/aer/infobulletins/2010pdf/AER_Angioedema.pdf