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Correspondence (letter to the editor): Differential diagnostic aspects are lacking.

Acute abdomen requires emergency treatment, including emergency diagnostic evaluation. In the introduction of their review article, the authors say that “While […] around 1% of all patients with acute abdomen have AMI [acute mesenteric ischemia], AMI is the cause of acute abdomen in up to 10% of patients aged over 70”, without explaining differential diagnostic aspects. 
 
Intestinal angioedema with massive mucosal swelling presents with similar symptoms; this seems to be neither more common nor rarer than AMI. 
 
Intestinal angioedema can have allergic triggers but can also be caused by taking angiotensin converting enzyme inhibitors and angiotensin II receptor blockers (many cases have been documented in the literature) or be provoked by non-steroidal anti-inflammatory drugs. An individual case of intestinal angioedema has been described in a patient after taking a calcium antagonist (1). 
 
Hereditary angioedema (HAE, a defect in C1-INH synthesis), angioedema with normal concentrations of C1-esterase-inhibitor but functional insufficiency, and angioedema based on acquired C1-esterase-inhibitor deficiency (acquired angioedema, AA) as well as idiopathic angioedema should also be included in the differential diagnostic evaluation. While a patient’s medical history can provide an early indication of angioedema due to medication, diet, or hereditary causes and thus prevent unnecessary laparotomy, hereditary angioedema and other forms need to be confirmed using specific laboratory-based examination. 
 
In case of clinical suspicion, this should include immunological determination of C1-INH, functional determination of C1-INH, measurement of C1, C2, C4, CH50, and, if required, measurement of autoantibodies against C1-INH (2). 
 
Adding intestinal angioedema as a differential diagnosis to the well-known range of causes for acute abdomen might be worth mentioning, in order to clearly differentiate from vascular-ischemic causes.