Necrotizing external otitis: a report of 46 cases

Abstract

Objectives: To define germs involved, clinical presentation, treatment regimen, and prognostic factors in necrotizing external otitis.

Patients and methods: Retrospective study reviewing a series of 46 patients treated during 10 years in a tertiary care center. Diagnosis was confirmed by using otomicroscopy, computed tomographic and/or magnetic resonance imaging scan and bone scintigraphy (Te 99 and Ga 26 bone scan). Patients were provided ceftazidime and ciprofloxacin intravenously and monitored using a Ga-67 bone scan. The following were assessed: presenting symptoms, general context, bacteriological analysis, imaging protocol sensitivity, complications, delay to healing, and cure rate.

Results: Sex ratio was 2.29 (mean age, 73.6 yr). The most common presenting symptoms were otalgia and otorrhea in 97.8 and 91.3%, respectively. Facial paralysis was present in 19.6% of cases. Thirty patients had diabetes mellitus (65.2%), and 8 were immunocompromised (17.4%). Pseudomonas aeruginosa was isolated in 69.2% of cases and was resistant to ciprofloxacin in 18.5%, but was susceptible to ceftazidime in all cases. Four patients died during the treatment (4.4%), but only 2 of disease. The mean delay to healing was 14 weeks (SD, 9.7). Healing rate was 95.6%. No relapse was observed after a mean follow-up of 78.4 weeks (SD, 36.5 wks). Two factors significantly influenced the prognosis: facial paralysis and existence of systemic factors for immune deficiency (p = 0.023 and 0.038, respectively).

Conclusion: The association of ciprofloxacin and ceftazidime was efficient in countering the increasing resistance of P. aeruginosa to quinolones. We propose a prognostic classification of necrotizing external otitis based on the presence of facial paralysis and/or systemic factors.