First branchial cleft anomaly presenting as a recurrent post-auricular abscess.

Embryological anomalies of the first branchial cleft are uncommonly encountered. They usually present as cysts, swellings, or fistulas in the pre-auricular or post-auricular area or high in the neck, which may become infected. Failure to recognise these unusual cases may result in misdiagnosis, inadequate treatment, and subsequent recurrence. Further definitive surgery may thus be complicated. A case is reported of a patient who attended accident and emergency on three occasions with an infected post-auricular cyst, which was treated by incision and drainage. It was subsequently found to be a first branchial cleft anomaly.