Necrotizing otitis externa: diagnosis, treatment, and outcome in a case series

- A delay of NOE diagnosis exists, affecting disease outcome.
- P. aeruginosa was the main causative organism (50%), with a 30% multidrug-resistance rate. A high rate (35%) of fungal pathogens was noted.
- Treatment with a single antibiotic agent may be insufficient. Treatment should be altered according to microbiologic culture results.
- Cranial neuropathies and CT finding of adjacent structural involvement correlate with adverse prognosis.
- We state the importance of limited surgical intervention and microbiologic cultures in disease treatment.

We reviewed 25 cases of patients diagnosed with necrotizing otitis externa in our tertiary university-affiliated medical center between 2009 and 2015. Mean overall hospitalization duration was 14.52 days, 95% of the patients showed specific seasonal incidence. Mean duration of symptoms prior to hospitalization was 6 weeks and the duration correlated with outcome. Only 8% of the patients presented with cranial neuropathies; however, this presentation correlated with adverse outcome. Pseudomonas aeruginosa was the main causative organism (50%), with a 30% multidrug-resistance rate. A high rate (35%) of fungal pathogens was noted. Seventeen patients (68%) were eventually operated; however, only 5 patients needed extensive surgery under general anesthesia. Computed tomography (CT) evidence of adjacent structures' involvement correlated with adverse outcome. Eighty percent of our patients improved clinically. The overall death rate was 12% and the disease-related mortality rate was 8%. Our findings state the importance of limited surgical intervention and microbiologic cultures in disease treatment. This is particularly important in patients with cranial neuropathies and CT finding of adjacent structural involvement that correlate with adverse prognosis. A rising pseudomonal antibiotic resistance and fungal infections may challenge antibiotic treatment in the future.