An update on the diagnosis and management of hereditary angioedema with abnormal C1 inhibitor.

Hereditary angioedema (HAE) is a rare genetic disease caused by a deficiency in functional C1-esterase inhibitor characterized by recurrent episodes of angioedema in the absence of associated urticaria. Subcutaneous swellings are experienced by virtually all patients with HAE, and dermatologists are likely to encounter this manifestation, requiring that they be knowledgeable about diagnosis and treatment options. Diagnosis of HAE is often delayed because several of the symptoms can mimic other disease states. Delays in diagnosis can lead to increased inappropriate treatment and decreased patient quality of life. Once a proper diagnosis is made, treatment needs to be targeted to the individual patient and includes on-demand therapy and an option for short- and long-term prophylaxis. On-demand therapy is required for all patients who are diagnosed with HAE and effective options include plasma-derived and recombinant C1 inhibitors, kallikrein inhibitors, and bradykinin B2-receptor antagonists. Options available for prophylaxis include plasma-derived C1 inhibitors, attenuated androgens, and antifibrinolytic agents, although the latter 2 options are associated with significant adverse events. This article reviews the diagnosis and options for effective management of patients with HAE.