Table 1.

Diagnostic criteria for idiopathic histaminergic acquired angioedema according to the international recommendations of the Hereditary Angioedema International Working Group

1. Histamine‐mediated angioedema characteristics 7	1. Sudden, pronounced swelling of the lower dermis and subcutis 2. Sometimes pain rather than itching 3. Frequent involvement below mucous membranes 4. Resolution that is slower than for wheals and can take up to 72 h
2. Exclusion of specific causes of angioedema 5	Causative agents of immediate hypersensitivity reactions Associated autoimmune/infectious disease C1 esterase inhibitor (C1‐INH) deficiency, and mutation in factor XII
3. Efficacy of anti‐histamines	Fifty per cent decrease in the frequency of symptoms following the introduction of the treatment with anti‐histamines