Author(s): ACM Thompson, I Zammit-Maempel, F Stafford, M Narayanan, NS Kanagasundaram Format Abstract We present an unusual case of necrotising otitis externa (NOE) causing a lower motor neurone facial nerve palsy in a patient with diabetes mellitus and receiving maintenance haemodialysis for end-stage renal disease (ESRD). Pseudomonas aeruginosa is the most common pathogen isolated in NOE, although our case involved the non-typical pathogens Aspergillus flavus and Proteus mirabilis. We discuss the need for diagnostic rigour and the importance of considering atypical infective pathology in patients with ESRD or diabetes mellitus. We review NOE with reference to causative agents, imaging strategies, prognostic indicators and treatment. Keywords Aspergillus flavus, diabetes mellitus, haemodialysis, malignant otitis externa, necrotising otitis externa, Proteus mirabilis, Pseudomonas aeruginosa Declaration of Interests No conflict of interests declared. PDF https://www.rcpe.ac.uk/sites/default/files/thompson.pdf Journal Keywords: Aspergillus flavusdiabetes mellitushaemodialysismalignant otitis externanecrotising otitis externaProteus mirabilisPseudomonas aeruginosa