[3] Frequency of preauricular sinus differs depending the population: 0.1–0.9% in the US, 0.9% in the UK, and 4–10% in Asia and parts of Africa.

[5] Preauricular sinuses can be associated with other defects that are not visible, one example being branchio-oto-renal syndrome.

[7] Most preauricular sinuses are asymptomatic, and remain untreated unless they become infected too often.

[8] Preauricular sinuses can be excised surgically, but often present a high risk of recurrence.

[9] Preauricular sinuses and cysts result from developmental defects of the first and second pharyngeal arches.