ABSTRACT

The clinical syndrome caused by C1-inhibitor (C1-INH) deficiency was first desc-ribed in 1881. The prevalence of the disease has been estimated to be 1/50,000. Although it is a rare disorder, C1-INH deficiency may develop during the course of diverse diseases. A 10-year-old girl was referred to our hospital because of swelling on her face and hands and abdominal pain. She had been diagnosed with familial Mediterranean fever (FMF) 5 years previously and treated with colchicine. The patient had had swelling on her face and hands monthly or bimonthly since 3 years old and the symptoms had been resolving without treatment within 1-2 days. Laboratory investigations revealed that her C4 complement level was 5 mg/dl (normal range: 10-40 mg/dl) and C1-INH level was 0.08 g/L (normal range: 0.15-0.35 g/L). C1-INH deficiency was diagnosed. Treatment with tranexa-mic acid was started. During the follow-up for 6 months she had only one mild attack of angioedema. To our knowledge, the coexistence of C1-INH deficiency and FMF has not been previously reported. We herein present a patient with C1-INH defici-ency that developed during the clinical course of FMF.