Question
What Causes Congenital Preauricular Fistula?
Answer
Congenital preauricular fistula is a common otolaryngological condition. It is caused by improper fusion of the second and third branchial arch tubercles during embryonic development or incomplete separation of the second branchial cleft. A fistula is a blind tube that can have branches and bends, with its external opening usually located above the antihelix. The lumen is covered with stratified squamous epithelium, containing scales that push against the fistula opening. Occasionally, some sticky sebaceous-like substances may flow out from the fistula opening. Infection can lead to redness, swelling, pain, and inflammation, which may recur repeatedly. This condition is an autosomal dominant genetic disease with incomplete penetrance. It is a remnant caused by incomplete fusion of the second branchial cleft during embryonic development.