Hereditary angioneurotic oedema (HANO) is an autosomal dominant disorder caused by a deficiency of the inhibitor protein Cl-esterase. Recurrent subcutaneous and/or submucosal oedema formation is a hallmark of this disease. HANO is a rare, but potentially life-threatening disorder with a mortality around 20-30%. Acute oedematous abdominal attacks of HANO can mimic a surgical emergency; this is exemplified by the case of a 14-y-old male patient with HANO admitted for such clinical manifestations.
Conclusion: Diagnostic clues include ascites and abnormalities of hepatic structure visible with ultrasound during the oedematous attack. The importance of appropriate treatment is emphasized.