Hereditary angioedema: Differential diagnosis, diagnostic tests, and family screening.

Hereditary angioedema is a rare, autosomal dominant genetic disorder that leads to sporadic episodes of swelling, which can affect any part of the body. With a prevalence of 1 in 10,000 to 1 in 50,000, there are other, more common causes of angioedema. Differentiating between bradykinin-mediated and histamine-mediated causes of swelling remains a major challenge. It is critical to develop an appropriate differential diagnosis, work through the various conditions, and obtain the pertinent laboratory evaluation to rule in or out the proposed diagnosis. As an autosomal dominant genetic disorder, there is a 50% chance with each pregnancy of passing on the genetic mutation in the SERPING1 gene. This review addressed the differential diagnosis to consider, the appropriate laboratory evaluation, and the importance of family screening.