Prevalence of external auditory canal exostoses in surfers

Objective: To determine (1) the prevalence of external auditory exostoses i n a population of surfers and (2) the relationship between the length of ti me spent surfing and the prevalence, severity, and location of the exostose s. Design: Cross-sectional epidemiological study. Setting: General community. Patients: Three hundred seven avid surfers (93.5% males and 6.5% females; a ge distributions: 11.2% were less than or equal to 20, 67.9% were 21 to 40, 17.5% were 41 to 50, and 3.3% were >50 years). Main Outcome Measures: Questionnaires focusing on surfing habits (number of years, geographic region, and number of days per year of surfing) were cor related with otoscopic findings. A simple grading system was devised, based on the degree of external auditory canal stenosis. Grades of normal, mild, moderate, and severe corresponded to 100%, 99% to 66%, 65% to 33%, and les s than 33% effective patent surface area, respectively. Results: There was a 73.5% overall prevalence of external auditory exostose s and a 19.2% overall prevalence of osteomas in the group studied. Of 441 e ars with exostoses, 54.2% were mild, 23.6% were moderate, and 22.2% were se vere. Of individuals who had surfed for 10 years or less, 44.7% had normal ear canals and only 6% had severely obstructed auditory canals. In comparis on, in the group that had surfed for longer than 20 years, only 9.1% had no rmal auditory canals and 16.2% were severely affected. Of surfers with no e xostoses, 61.1% had surfed for 10 years or less. In contrast, of surfers wi th severe exostoses, 82.4% had surfed for more than 10 years. Finally, the lesions seemed to affect all external auditory canal quadrants equally. Conclusion: A positive association exists between the amount of time indivi duals spend surfing and the presence and severity of exostoses of the exter nal auditory canal.