Severity of hereditary angioedema, prevalence, and diagnostic considerations.

Hereditary angioedema (HAE) is a rare disorder, characterized by intermittent attacks of swelling in any part of the body, without the presence of hives. This lifelong disease typically presents in the first 2 decades of life, and is commonly associated with a deficiency in functional C1 esterase inhibitor (C1-INH) activity. C1-INH levels may be decreased or normal, with an accompanied decrease in functionality, depending on the type of HAE present. The frequency and severity of attacks are highly variable among patients with HAE, but can have a significant impact on a patient's quality of life, and may be fatal if not properly managed. Early diagnosis of the disease can lead to the development of an individualized treatment plan to assist with prevention and management of angiodema attacks. Delays in diagnosis remain, as healthcare professionals often fail to include HAE in the differential diagnosis when patients present with attacks, and patients therefore often go undiagnosed or are misdiagnosed for several years before a diagnosis of HAE is made. It is important for providers to recognize the most common clinical features of HAE and how to evaluate patients to effectively diagnose, prevent, and treat future attacks.