A number of clues in the patient’s history may suggest that a patient with recurrent angioedema has the hereditary form. Name some.

Between 75% and 85% of patients with hereditary angioedema (HAE) give a positive family history of similar attacks. The attacks of angioedema themselves are characterized by absence of urticaria and pruritus, both common with idiopathic angioedema. In HAE, episodes of angioedema are often triggered by trauma such as surgery. However, such a triggering event may not be evident. Significant upper airway obstruction is seen almost exclusively in HAE, as opposed to ordinary idiopathic angioedema. Attacks of severe abdominal pain are common in HAE, representing edema of the bowel wall. Finally, attacks of HAE typically progress for several days and respond poorly to treatment with antihistamines or epinephrine.