External auditory canal cholesteatoma and benign necrotising otitis externa: clinical study of 95 cases in the Capital Region of Denmark

Objective To identify epidemiological and pathophysiological factors, and treatment strategies, in external auditory canal cholesteatoma and benign necrotising otitis externa. Methods A retrospective case study was conducted of patients suffering from external auditory canal cholesteatoma and benign necrotising otitis externa admitted to tertiary hospitals, in the Capital Region of Denmark, over a five-year period. Results Eighty-three patients (95 ears) with external auditory canal cholesteatoma or benign necrotising otitis externa were identified. A minimum incidence rate of 0.97 per 100 000 inhabitants per year was demonstrated. Sixty-eight per cent of cases had a history of smoking. Most lesions (74 per cent) were localised in the floor of the ear canal. Treatment time was 3.2 months for patients who had surgery and 6.0 months for those who received conservative treatment. Conclusion It is suggested that external auditory canal cholesteatoma and benign necrotising otitis externa are in fact the same disease, and therefore the diagnosis of external auditory canal cholesteatoma should be changed to benign necrotising otitis externa. Microangiopathy has a leading role in the aetiology. Surgery should be conducted in most cases.