Tonsillectomy in a patient with hereditary angioedema after prophylaxis with C1 inhibitor concentrate.

Background: A 15-year-old young man with a history of recurrent streptococcal pharyngitis and hereditary angioedema presented for tonsillectomy. Preoperative physical examination was normal with the exception of enlarged pharyngeal tonsils with crypts and pustules; there was no evidence of angioedema. Laboratory studies were remarkable for a C4 level of 8 mg/dL (normal 20-50 mg/dL) and C1 inhibitor (C1 INH) level of 4 mg/dL (normal 11-26 mg/dL).

Objective: To report the use of C1 INH concentrate as prophylactic treatment for a patient with hereditary angioedema who required tonsillectomy.

Methods: The patient was treated with stanozolol 4 mg po quid and clindamycin 150 mg po tid during the week before the procedure. Two hours prior to surgery, he received 2300 plasma units of intravenous C1-inhibitor (Human) Vapor Heated, IMMUNO (IMMUNO Clinical Research Corporation, New York, NY).

Results: Approximately eight hours after an uncomplicated tonsillectomy, the patient began to experience crampy abdominal pain, typical of his hereditary angioedema. Beginning 22 hours after surgery, he had facial swelling and complained of difficulty swallowing and the sensation of throat swelling. The symptoms resolved over the next eight hours. Serial laboratory examinations revealed: [table: see text]

Conclusions: We believe that the occurrence of abdominal pain, facial swelling, and difficulty swallowing suggests that this patient may have experienced a mild, generalized flare of hereditary angioedema during the postoperative period in spite of prophylactic therapy with both anabolic steroids and C1 INH concentrate. This serves as a reminder that patients with hereditary angioedema require close observation following invasive procedures even after premedication with stanozolol and C1 INH concentrate.