Hereditary angioedema (HAE) is a rare autosomal dominant disease caused by low levels of the plasma protein C1 inhibitor (C1-INH).
Patients present with recurrent episodes of angioedema, without urticaria or pruritus. Sites commonly affected are the skin or mucosal surface of the upper respiratory and gastrointestinal tracts.
Laryngeal involvement may cause fatal asphyxiation.
Treatment consists of prophylaxis, management of acute attacks, and prophylactic therapy in situations where attacks may occur.