Angioedema: Diagnosis and treatment approaches

Angioedema (AE) is defined as sudden, localized and transient swelling of the skin and/or mucous membranes. This swelling condition is a result of interstitial edema from vasoactive mediators increasing the permeability of postcapillary venules of the subcutaneous and submucosal tissues. When localized to the skin, it presents as asymmetric, nonpitting, nondependent, and occasionally painful edema. However, mucosal attacks, such as laryngeal edema and bowel involvement can produce severe discomfort and life-threatening symptoms. There are several forms including those involving dysfunction or depletion of the C1-inhibitor gene (classical hereditary AE types and acquired AE), allergic AE, drug-induced AE (nonsteroidal anti-inflammatory drug-induced AE, angiotensin converting enzyme inhibitor-induced AE), idiopathic and a recently described form, HAE type 3. These various forms of AE have overlapping symptoms, but some unique clinical and historical features as well as presence of accompanying urticaria can aid in the differential diagnosis. The key to successful management is to rule out conditions that masquerade as AE, detection and avoidance of triggers, early recognition of attacks, and aggressive airway management when warranted. In this article, common and rare forms as well as clinical symptoms, differential diagnosis, and treatment approaches for AE are reviewed.