Hereditary angio-oedema

Hereditary angio-oedema is caused by a heterozygous deficiency of C1 inhibitor. This inhibitor regulates several inflammatory pathways, and patients with hereditary angio-oedema have intermittent cutaneous or mucosal swellings because of a failure to control local production of bradykinin. Swellings typically evolve in several hours and persist for a few days. In addition to orofacial angio-oedema, painless swellings affect peripheries, which causes disfigurement or interference with work and other activities of daily living. Angio-oedema affecting the gastrointestinal tract or abdominal viscera causes severe pain often with vomiting due to oedematous bowel obstruction. About 2 of swellings involve the larynx and can be fatal if untreated. About 50 of patients have laryngeal swellings that are potentially fatal despite prophylaxis. In this Seminar we review the clinical features, diagnosis, and management of hereditary angio-oedema, with specific emphasis on the new treatments available for acute swellings.