Exostoses of the external auditory canal in white-water kayakers

Exostoses of the external auditory canal are benign bony tumors associated with frequent cold-water exposure. Obstruction may lead to conductive hearing loss and recurrent otitis externa, requiring surgical correction when symptoms become intolerable. This study aimed to characterize the prevalence of exostoses in white-water kayakers and identify associated risk factors and protective measures.

Cross-sectional.

Six hundred eleven white-water kayakers from across the United States were included in the study. Percent occlusion was graded as minimal (<25%), moderate (25%-75%) or severe (>75%). Subjects completed a survey of risk factors and protective measures. Kruskal-Wallis and chi(2) tests were performed to determine significant associations with percent occlusion. A multivariate proportional odds regression model was fit to adjust for confounding between the variables.

The prevalence of exostoses in kayakers was 79% (482/611); 13% (78/611) had >or=75% occlusion. Percent occlusion was associated with total years kayaked (P < .001), frequency >or=1 day/week (P < .001), male gender (P < .001), and increasing age (P = .005), although frequency, gender, and age were confounded by total years. Styles that involve repeated submersion were also associated with greater occlusion (freestyle, P = .036; squirt, P = .016). Subjects who used earplugs for a greater proportion of their kayaking career were less likely to have exostoses (P < .001). When adjusted for confounding, only total years (P = .0003) and age (P = .0027) remained significant.

Kayakers are the first inland population to experience exostoses at the rates seen in coastal populations (e.g., surfers). When used long-term, earplugs may be protective.