A rare autosomal dominant disease marked by episodic bouts of subcutaneous and submucosal edema, especially of the gastrointestinal tract or the upper airways. It is caused by the hereditary lack of a protein (Cl INH) that inactivates complement or by the malfunction of this protein. Physical trauma or psychological stress may precipitate attacks. The symptoms usually worsen after puberty. Anabolic steroids are typically used to treat HAE.
A deficiency in complement, a component of the immune system, characterized by the obstruction of lymphatic vessels leading to temporary swelling (edema) in various regions of the skin, mucous membranes, and occasionally internal organs.