Standardised treatment protocol for necrotizing otitis externa: retrospective case series and systematic literature review

Abstract

There is currently no consensus on the most effective treatment protocol for necrotizing otitis externa (NOE). This article aims to produce a NOE treatment protocol from the literature and clinical experience. A total of 26 case series from the literature were reviewed in combination with a retrospective case series of inpatients from Hull University Teaching Hospitals NHS Trust from 2013-2018. Over 5 years, 40 patients were identified, with only 29 being analysed due to unavailable or incomplete case notes. In the literature review, the most common bacterial species causing NOE was Pseudomonas aeruginosa. Resistance to ciprofloxacin was prevalent, however multidrug resistance was rare. Ciprofloxacin and ceftazidime were the most widely used antibiotics. No ceftazidime resistance was reported in the literature or in our cohort. The average age of the patients in our cohort was 80 years. Moreover, 62% had either diabetes mellitus or were immunosuppressed. One patient died directly due to NOE-related sepsis. Intravenous ceftazidime monotherapy was mostly used. The duration of treatment was 6-7 weeks, with no relapses documented. Ceftazidime monotherapy was an effective empirical treatment in our cohort, and a total duration of 6-7 weeks of antibiotics was sufficient. We have created a standardised treatment protocol based on our findings that will need to be validated in a larger cohort of patients.