Case report of treatment with Icatibant for recurrent throat swelling due to hereditary angioedema

Department of Medicine, Division of Clinical Immunology and Allergy, McMaster University, Hamilton, Ontario, Canada, L8N 3Z5 We report a 64 year-old woman with longstanding hereditary angioedema who previously required a tracheotomy. In September 2005, while receiving prophylactic Danazol she noticed a left sided swelling involving her throat and uvula that was of moderate intensity by 1110h. She came to hospital and received icatibant 30 mg sc at 1330h when the swelling was 1 cm in size. One hour later the swelling was 4 mm in size. After 2 hours the swelling was gone and did not recur. Because of increased frequency of angioedema, after December 2008 she started taking C1 esterase inhibitor 2000 PU once weekly, and Danazol 400 mg daily plus additional C1 inhibitor infusions when symptoms were uncontrolled. She received icatibant in August 2009 for throat swelling. Her symptoms subsided and admission wasn’t required. In November 2009, she was admitted for a bowel obstruction due to angioedema. She received a single dose of icatibant, but did not note any benefit. Treatment with icatibant was not repeated. With conservative treatment and additional C1 esterase inhibitor, her bowel obstruction gradually resolved over 3 days. Her C4 was undetectable (<0.02 g/L) and C1 esterase inhibitor was within the normal range (0.22 g/L normal 0.21-0.39 g/L). We present a patient with hereditary angioedema whose throat angioedema responded to icatibant but a single dose of icatibant did not have significant effect on bowel angioedema. Physicians should consider icatibant for breakthrough attacks not prevented by prophylactic therapy.