The prevalence of exostoses in the external auditory meatus of surfers.

Fifty-four surfers and 38 surf life savers were examined and questioned in order to determine the prevalence of exostoses. Seventy-three per cent had evidence of body exostoses in the external auditory meatus. Forty per cent had their ear canals narrowed by 50% or more. The relationship between the number of years spent surfing or life saving and the extent of canal stenosis was highly significant (P < 0.00001). Left and right ears were affected equally in this series and the obstruction appears to begin after approximately 7 years and is further aggravated by continued surfing. Over 90% of subjects who had participated for longer than 10 years had some evidence of exostoses. There was no significant association between the number of days per year or the number of hours per day spent surfing and the development of surfer's ear in this sample. Those who participated in their water sport over winter had significantly more exostoses than those who did not (P < 0.0001). Those who lived in the South Island (colder water) had more surfer's ear than those in the North Island (warmer water).