From wipeout to drill out: a history of exostosis management and Australian surfing

The evolution of treatment for a distinctly Australian affliction

External auditory canal exostoses are benign, localised bony growths that form in the ear canal. They are classically described as reactive lesions caused by repeated exposure to cold water and wind. This results in chronic inflammation of the periosteum of the external canal leading to the formation of multiple, nodular bony outgrowths of the medial canal that are covered by thin skin. Exostoses tend to remain asymptomatic until they grow to significantly narrow the external auditory canal (Box 1). At this stage, they cause water trapping and hydration of the external canal skin, resulting in recurrent otitis externa. Acute otitis externa (often referred to as swimmer’s ear) is a common complication of exostoses, with management consisting of ear toileting, local antibiotic therapy (drops and ointment), and maintaining a dry ear. In its latter stages, exostoses may completely occlude the external canal, and patients typically present following repeated infection or hearing loss. Anatomically, exostoses typically occur in groups of three: anteriorly, posteriorly and superiorly based. These correspond to the three ossification centres of the tympanic ring, which is the bony structure which supports the ear drum, and the site from which exostoses arise.1