990. Fungal Malignant Otitis Externa: Clinical and Therapeutic Features

Background Fungal malignant otitis externa is a rare, but a serious infection that might lead to death if not promptly diagnosed and treated. We aimed to study the clinical, therapeutic and evolutionary features of fungal malignant otitis externa. Methods We conducted a retrospective study including all cases of fungal malignant otitis externa hospitalized in the infectious diseases department between 2003 and 2020. Results We included 35 patients with a mean age of 68±11 years. There were 18 males (51.4%). All patients were diabetics, and 7 patients had a previous medical history of otitis externa (20%). The use of topical corticosteroids was noted in 10 cases (28.5%). The revealing symptoms were otalgia (97.1%), otorrhea (82.9%) and cephalalgia (54.3%). Physical examination revealed tenderness to palpation of the mastoid bone in 21 cases (60%) and the temporomandibular joint in 16 cases (45.7%). Facial paralysis was noted in 14.3% of the cases. Otoscopic examination revealed stenosis of the external auditory canal (94.3%), granulation tissue (34.3%) and a polyp (31.4%). Candida species were isolated in 22 cases (62.8%) represented by Candida parapsilosis in 15 cases (42.8%) and Candida albicans in 5 cases (14.2%). Serological tests detecting Candida were positive in 12 cases (34.2%). Aspergillus species were isolated in 13 cases (37.1%) represented mainly by Aspergillus flavus in 7 cases (20%). Positive serology results for Aspergillus were noted in 8 cases (22.8%). A polyp or granulation tissue biopsy, performed in 12 cases (34.2%), revealed non-specific inflammatory reaction (28.5%) and the presence of fungal hyphae and spores (5.7%). After empirical antibiotics treatment, patients received fluconazole in 18 cases (51.4%) and voriconazole in 17 cases (48.6%). The median duration of treatment was 3 [1.5-12] months. Both surgery and hyperbaric oxygen therapy were indicated in one case (2.8%). Complications including the onset of contralateral otitis (14.3%) and endocranial extension (8.6%) were noted. The disease evolution was favorable in 65.7% of the cases. Four patients were dead (11.4%). Conclusion Involvement of fungal species in malignant otitis externa should be considered in front of the absence of improvement with antibiotic. Prompt treatment might prevent complications. Disclosures All Authors: No reported disclosures

1024 A Case-Controlled Series Examining the Utility of Nuclear Medicine Imaging in The Diagnosis and Management of Malignant Otitis Externa

Introduction This study aimed to assess whether combination modality imaging (CT, and/or Technetium/Gallium) had any additional benefits over single modality imaging (CT) in the management of malignant otitis externa (MOE). Method A six-year retrospective case-controlled series was performed including 73 patients presenting with a potential diagnosis of MOE. Results CT imaging was undertaken in 69/73 patients, and of these the CT confirmed the diagnosis in 58% (40/69). Of the 42% (29/69) of CT negative patients, 25 underwent Technetium scanning, revealing 40% (10/25) to be negative. These patients were discharged on a short course of topical and oral therapy with no disease recurrence. Gallium scan results, performed at the end of treatment, were more inconsistent, with 47% (25/53) of imaging still positive despite extended intravenous/oral/topical therapy. However,40% (10/25) of these had their therapy stopped without any further disease relapse. Conclusions Combination modality imaging, with CT and Technetium, did infer additional benefit over single modality imaging using CT. However, this was not the case for Gallium scanning, used to determine treatment end, which seemed to be poorly representative of residual disease presence. This study was utilised to provide a management algorithm to guide future practice.