This critical review of the AR literature has identified several strengths; providers can be confident that treatment decisions are supported by rigorous studies. However, there are also substantial gaps in the AR literature. These knowledge gaps should be viewed as opportunities for improvement, as often the things that we teach and the medicine that we practice are not based on the best quality evidence. This document aims to highlight the strengths and weaknesses of the AR literature to identify areas for future AR research and improved understanding.

The frequency of aspirin intolerance by history in 2,592 normal individuals was 0.3%. Although the frequency of aspirin intolerance was similar in adults and children, the bronchospastic type predominated in adults, and only the urticarial type was found in normal children. The frequency of recurrent urticaria, regardless of etiology, was significantly greater in adults than in children (3.8% vs. 0.3, P less than 0.001). In adults the frequency of aspirin intolerance was over 20 times greater in individuals with recurrent urticaria than in normal individuals (6.5% vs. 0.3%, P less than 0.001).

<title/> Hereditary angioedema (HAE) is a rare autosomal dominant genetic disorder characterized by swelling of subcutaneous, mucosal, and submucosal tissue without associated pruritus or wheals caused by a temporary localized increase in vascular permeability. Swelling attacks primarily affect the cutaneous tissue, abdominal viscera, genitals, or airways. <title/> Reports of the prevalence of HAE C1 inhibitor (C1-INH) deficiency varies widely, from 1:50,000 to 1:100,000. The prevalence of HAE normal C1-INH is unknown but is likely much lower than HAE C1-INH. Approximately one-third of patients with recurrent angioedema without wheals have HAE. <title/> The burden of disease for patients with HAE is substantial. Attacks are unpredictable with respect to frequency, severity, and the site that swells. Laryngeal attacks can be fatal if not treated promptly and appropriately. Feelings of stress, anxiety, and depression can trigger attacks, and begin a cycle of attacks that cause anxiety that, in turn, triggers further attacks. Despite full physical recovery between attacks, patients often experience continual emotional impairment and reduced quality of life (QoL). Absenteeism from work and presenteeism at work or educational activities for patients and caregivers increase stress and reduce productivity during and between attacks. Missed opportunities for career development are common. <title/> Significant advances have been made in the past decade to expand both acute and prophylactic treatment options for patients with HAE, lowering both the disease and treatment burden, and improving the QoL of patients with HAE.