651. Comparative Analysis Between Bacterial And Fungal Malignant Otitis Externa

BACKGROUND: Malignant otitis externa is a fatal infection of the external ear and temporal bone. Pseudomonas aeruginosa is the most common causative organism, while fungi are a rare cause of malignant otitis externa. We aimed to compare the clinical, therapeutic and evolutionary features between bacterial and fungal malignant otitis externa. METHODS: We conducted a retrospective study including all patients hospitalized for malignant otitis externa in the infectious diseases department between 2000 and 2018. RESULTS: Overall, we encountered 82 cases of malignant otitis externa, among which there were 54 cases (65.9%) of bacterial malignant otitis externa (BMO) and 28 cases (34.1%) of fungal malignant otitis externa (FMO). The males were predominant among BMO cases (57.4% vs 50%; p=0.5). Patients with FMO were significantly older (70±9 years vs 61±10 years; p< 0.001) and had medical history of diabetes mellitus more frequently (96.4% vs 77.8%; p=0.03). The use of topical corticosteroids was significantly more reported among FMO cases (28.6% vs 5.6%; p=0.006). Otalgia (96.4% vs 81.5%), otorrhea (75% vs 66.7%) and cephalalgia (46.4% vs 42.6%) were the revealing symptoms among FMO and BMO, respectively, with no significant difference. Tenderness to palpation of the mastoid bone (64.3% vs 38.9%; p=0.02) and stenosis of the external auditory canal (92.9% vs 72.2%; p=0.02) were significantly more frequent among FMO cases. Complications were significantly more frequent among FMO cases (42.9% vs 9.3%; p< 0.001). Treatment duration was significantly longer among FMO cases (70[40-90] days vs 45[34-75] days; p=0.03). CONCLUSION: Our study showed that FMO affected more frequently the elderly and diabetic patients, when compared with BMO. Regardless of the causative agent, the clinical presentation was similar. However, the outcome was poor among FMO cases with the occurrence of complications, requiring a longer duration of treatment. DISCLOSURES: All Authors: No reported disclosures