Hereditary angioedema: a brief review of new developments.

Background: Angioedema is a serious medical condition characterized by recurrent non-pitting tissue edema. Hereditary (HAE) forms of this disorder are potentially fatal.

Methods: PubMED, Up to Date and Cochrane Library databases were used to identify scholarly peer reviewed original research or review articles on angioedema. Search terms used were: angioedema, HAE, ACE inhibitor induced angioedema, acquired angioedema, type III HAE (now termed HAE with normal C1-INH), diagnosis of HAE, and treatment of HAE. Inclusive dates of the search were 1946 through 2013. Articles on urticaria were excluded.

Results: The pathophysiology, clinical manifestations, differential diagnosis and treatments of angioedema are presented. Three variants of HAE are discussed and differentiated from acquired, ACE induced and allergic types of angioedema. Emphasis is placed on understanding that HAE is mediated by bradykinin, not histamine, and is therefore unresponsive to antihistamines, corticosteroids and epinephrine. In contrast, newer therapies that replace C1-INH or block bradykinin production or action are the appropriate treatments for prophylaxis and acute treatment of HAE.

Conclusion: Recognition of HAE by primary care providers and distinguishing it from allergic histamine mediated angioedema is essential in preventing recurrent attacks and avoiding inappropriate therapy, and may be life-saving.