Culture-negative necrotizing otitis externa: diagnosis and management

Objective We aim to describe the clinical features and therapeutic management of necrotizing otitis externa (NOE) with negative culture. Patients and methods We included all patients with NOE, who were treated in the period between 2008 and 2020 in our department. Results A total of 25 cases of NOE were included. The result of the culture was negative in 13 cases (52%). All patients received a local treatment prior to hospitalization, and eight patients (61.5%) received oral antibiotic. A sampling of the otorrhea was done for all patients. Fungal serology was performed for six patients; it was positive in two cases. The prescribed first-line was ciprofloxacin in combination with ceftazidime for 10 patients, while it was based on the use of imipenem with ciprofloxacin for 2 patients and one patient only received ciprofloxacin. An improvement was noted in 10 cases (77%). The second-line treatment in the three cases of resistance was imipenem with ciprofloxacin in one case. For the two patients with a positive aspergillus serology, one patient received teicoplanin, fusidic acid, imipenem, and voriconazole and the other patient received voriconazole. The total duration of the treatment was a minimum of 6 weeks. An improvement was noted in all cases, and recurrence was noted in 3 cases. Conclusion In our study, there were no clinical or radiological specificities noted in NEO with negative culture. Sampling must be repeated. Fungal origin should be suspected in refractory forms and empiric antifungal treatment may be useful.