Preauricular sinus: clinical course and associations.

Objectives: To evaluate the clinical course of congenital preauricular sinus (PAS) up until adulthood and to determine its association with congenital ear and renal abnormalities.

Design: Cohort survey.

Setting: Medical screening facility at a military base.

Participants: All individuals in a cohort of male subjects who were medically assessed for conscription into the army between September 1, 2003, and March 31, 2004.

Interventions: Subjects identified as having PAS were further evaluated with pure-tone audiometry and renal ultrasonography.

Main Outcome Measures: Presence of PAS and associated hearing and renal abnormalities.

Results: Of 10 734 male subjects (median age, 19 years; range, 16-26 years) screened, 121 (1.13%) were found to have PAS, all of which were isolated. The point prevalence of PAS in Chinese, Malay, and Indian subjects was 1.36%, 0.69%, and 0.17%, respectively. Of the 29 subjects (24.0%) who developed symptoms (mainly sinus discharge), most had recurrent symptoms, and 7 (24.1%) of the 29 had onset of symptoms after age 16 years. Only 1.7% and 2.6% of the subjects had associated hearing loss (sensorineural) and renal deformity (minor in nature), respectively.

Conclusions: In a study of young adult males with PAS, associations with ear and renal abnormalities were found to be rare, although PAS had widely been acknowledged to be associated with these congenital defects. Up until adulthood, about one quarter of all lesions became symptomatic. Of those who developed symptoms, almost one third did so after age 16 years. The most common symptom was sinus discharge, which tended to be recurrent.