A congenital preauricular fistula is a condition in which there is a small, painful, red, swollen skin and a yellow discharge from the eye. This is a congenital condition in which the gill slit does not heal completely during embryonic development, leaving a fistula in which there is a secretion that causes infection when the resistance is reduced, resulting in a local abscess. In this case, the abscess needs to be incised, drained, and treated with anti-inflammatory therapy, and after the abscess disappears, the fistula as a whole needs to be removed by secondary surgery.