Van Gilse1 reported that exostoses in the external auditory canal are often found in cold water swimmers. In a discussion of his paper at the Collegium Otolaryngologicum, in Venice, in 1937, it was brought out by Italian otologists that exostoses are rarely seen in Italy. The inference is that Italian swimmers, who usually use the warm water of the Adriatic, are not subject to exostosis to the same extent as are the Dutch, who are wont to swim in the cold waters of the North Sea or in the Baltic.
Of 25 patients with hyperostosis and 9 with discrete exostoses of the external auditory canal observed in the last three years in the office practice and in the hearing clinics of one of us, (E. P. F.)2 all but 4 had been ardent cold water swimmers. Two of the 4 exceptions swam on college swimming teams in heated
FOWLER EP, OSMUN PM. NEW BONE GROWTH DUE TO COLD WATER IN THE EARS. Arch Otolaryngol. 1942;36(4):455–466. doi:10.1001/archotol.1942.03760040009001