A novel method for the determination of exostosis severity in the external auditory canal

Key points
- Exostosis is a benign, irreversible growth of bone in the external auditory canal commonly seen in aquatic enthusiasts such as surfers and swimmers.- Traditional assessment of the severity of exostosis is by visual estimate during otoscopic exam, with four grades: Grade 0 (no identifiable exostosis), Grade 1 (<33% obstruction), Grade 2 (≥34%–≤66% obstruction) or Grade 3 (>67% obstruction).- Gold standard diagnostic assessment of exostosis severity is traditionally via computerised tomography; however, this technique exposes the patient to high dose radiation, is expensive and cannot typically be conducted during appointments.- We describe a novel analysis of exostosis using National Institute of Health public domain software which allows accurate determination of the severity of exostosis from otoscopic exam images during patient consults.- ImageJ analyses presents an accurate, highly reliable, time and cost-efficient method of exostosis analysis in clinical practice and research.