Immunosuppression, infection, and epidermal compromise - an aetiological triad for necrotising otitis externa which highlights potential modifiable risk factors.

Abstract

A key clinical feature of necrotising otitis externa is granulation tissue arising from the ear canal, representing epidermal compromise. The aim of this work was to explore the role of epidermal compromise in the aetiology of necrotising otitis externa. A structured risk factor history was taken from 54 patients diagnosed with necrotising otitis externa between 2017 and 2022. Primary care records were also reviewed. A total of 94 per cent of patients reported incidents of potential epidermal compromise preceding severe pain onset, including a 35 per cent incidence of ear syringing. A total of 94 per cent of patients were immunosuppressed, including 78 per cent with diabetes. All patients had medical co-morbidities. This study proposed an aetiological triad for necrotising otitis externa: immunosuppression, infection and epidermal compromise. Epidermal compromise is a potentially modifiable risk factor for necrotising otitis externa. Meticulous primary ear care for older adult, diabetic and immunosuppressed patients is recommended. These populations should never undergo ear syringing and should avoid ear canal trauma and prolonged exposure to moisture.