[Three cases of external auditory exostoses in a habitual sauna user]

Exostoses are benign bony excrescences of the external auditory canal, commonly encountered in people who avidly engage in aquatic activities, hence the name "surfer's ear". Exostoses are more prevalent in cold water surfers, and additional years of surfing increase one's risk not only for developing an exostosis but also for developing more severe lesions. Exostoses remain clinically silent until they become large enough to impair the egress of epithelial debris and water from the canal, in which case there may be an associated external otitis and fluctuating hearing loss. Histologically, they demonstrate a laminated structure consistent with a periodic growth pattern. They may also cause a hearing loss by impinging upon the tympanic membrane and manubrium. Symptomatic relief is attained by surgical removal and skin grafting of the epithelially denuded areas of the bony walls of the external auditory canal. We report herein on 3 cases of exostoses which developed in patients who had a habit of taking a cold water bath after a hot sauna for more than 15 years: in spite of the limited time of exposure to cold water stimulation, alternating exposure to the hot environment of the sauna and cold water baths seemed to have acceralated the formation of the exostoses.