[Sonography in hereditary angioedema: typical findings demonstrated by the example of 3 cases].

Hereditary angioedema (HAE) is a hereditary disorder (deficiency of C1 esterase inhibitor) with spontaneous cutaneous and subcutaneous edemas, which involve the gastrointestinal tract in 50 - 75 %. Recurrent abdominal pain attacks in younger patients with an ultrasonographic evidence of aszites (up to 1 - 2 litres are frequent), should always let think of a HAE. Additionally in one female patient we found pleural effusion repeatedly during the episodes. HAE typically shows segments of GI-tract with a marked wall thickening. In our patients stomach (2 x), small bowel (2 x) and colon (1 x) were involved. Obstruction of the lumen by the edema may cause vomiting or ileus. By means of high-resolution sonography we could show for the first time that only mucosal and submucosal layer were affected, the L. muscularis propria was preserved. Characteristic was a hypoechoic thickening of the interior layers of the wall: In one patient we found anechoic lacunae within the mucosal layer, probably corresponding to a bullous edema. An accurate ultrasonic examination enables a reliable judgement of the severity level of HAE. It can contribute in this way to the decision whether the application of C1-INH-concentrate is necessary or not.