ACE and acquired angioedema: ,39 Furthermore, it is important to distinguish HAE-C1INH from clinically similarly presenting acquired angioedema conditions (eg, acquired angioedema due to C1INH deficiency, acquired angiotensin-converting enzyme inhibitor–associated angioedema, idiopathic histaminergic angioedema, and idiopathic nonhistaminergic angioedema) to enable family screening of patients with HAE as recommended by international guidelines.9