Hereditary angioedema diagnosis is based on clinical and laboratory criteria. The suspicion of hereditary angioedema is high if a patient has a recurrent angioedema, without urticaria, lasting more than 24 hours, is non-pruritic, non responsive to antihistamine or corticosteroids, is associated with a serpiginous rush, or a unexplained colicky recurrent abdominal pain, have a family history and a low C4 level. If serum C4 levels are low, measurment of C1-INH concentration and functionality are recommended. In some cases, HAE type identification requires C1-INH antigen and genetic testing.

Last update: 08.25:2009