Ascites and suspected acute abdomen in hereditary angio-oedema due to C1-inhibitor deficiency

History and clinical findings: A 35-year-old man, for 8 years known to have hereditary angio-oedema with recurrent cutaneous swellings and occasional attacks of gastrointestinal pain, developed very painful, colic-like upper abdominal symptoms and frequent vomiting. Investigations: Routine laboratory tests were normal, except for leucocytosis of 18 200 WBC/mu l. The plasma concentrations of C1-esterase inhibitor (5.6 mg/dl) and of complement factor C4 (10.0 mg/dl) were reduced. Computed tomography revealed about 500 ml free fluid, a perihepatic effusion and definite oedematous thickening of the ileal wall. Treatment and course: During conservative treatment with infusions and no food by mouth the symptoms regressed. Abdominal ultrasonography was normal (no free intraabdominal fluid). Since discharge (now more than 15 months ago) the patient has been on danazole medication (200 mg/d). Conclusion: Recurrent gastrointestinal colics are typical of for hereditary angio-oedema and can imitate an acute abdomen. Concurrent ascites has only recently been described. Appropriate instruction of the patient and his/her medical practitioner is important to avoid unnecessary laparotomy.