Characteristics, management and outcome of a large necrotising otitis externa case series: need for standardised case definition

Abstract Background Necrotising otitis externa is a severe ear infection for which there are no established diagnostic or treatment guidelines. Method This study described clinical characteristics, management and outcomes for patients managed as necrotising otitis externa cases at a UK tertiary referral centre. Results A total of 58 (63 per cent) patients were classified as definite necrotising otitis externa cases, 31 (34 per cent) as probable cases and 3 (3 per cent) as possible cases. Median duration of intravenous and oral antimicrobial therapy was 6.0 weeks (0.49–44.9 weeks). Six per cent of patients relapsed a median of 16.4 weeks (interquartile range, 23–121) after stopping antimicrobials. Twenty-eight per cent of cases had complex disease. These patients were older ( p = 0.042), had a longer duration of symptoms prior to imaging ( p < 0.0001) and higher C-reactive protein at diagnosis ( p = 0.005). Despite longer courses of intravenous antimicrobials (23 vs 14 days ; p = 0.032), complex cases were more likely to relapse ( p = 0.016). Conclusion A standardised case-definition of necrotising otitis externa is needed to optimise diagnosis, management and research.