Recurrent angio-oedema--three cases of C1 inhibitor deficiency.

C1 Inhibitor deficiency is a rare disorder, characterised by recurrent angio-oedema of skin, upper respiratory and gastrointestinal tracts. It can be a mimicker of acute abdomen or anaphylaxis to drug or food and lead on to unnecessary overtreatment. Three case reports of such patients with history of recurrent abdominal pain and angio-oedema due to C1 Inhibitor deficiency is reported here.