A retrospective study of 43 cases of fungal malignant external otitis

Abstract

Malignant external otitis (MEO) has a frequent bacterial origin, but we are currently witnessing the emergence of fungal agents, which poses difficulties in diagnosis and management. The aim of our work is to analyze the epidemiological and clinical profile of fungal MEO and to study the antifungal susceptibility of fungi involved.Our study is retrospective collecting 43 patients treated for fungal MEO between 2010 and 2019.Clinical, biological, and radiological data were collected from patient hospitalization records. Identification of yeasts was done by YST vitek^®2 card.The antifungal susceptibility testing was performed for yeasts by the AST vitek^® 2 card and for other fungi by the E-test technique. The average age was 66 (± 12) years. We noted a male predominance in 63 % (n=27). Diabetes was found in 86%. Otalgia was a constant symptom. Cranial nerve palsies were observed in 16% (n=7) of cases. CT showed bone lysis in 74% (n=31>) of cases and Tc99 bone scintigraphy revealed hyperfixation in 100%(n=43) of cases. Candida spp (n=21), Aspergillus spp (n=18), and Geotrichum capitatum (n=2) were isolated. No resistance to antifungals has been demonstrated for Candidayeasts. Geotrichumcapitatum isolates were resistant to fluconazole and caspofungin. Aspergillus isolates were resistant to amphotericin B and caspofungin in 50% (n=9) and 72% (n=12) of cases, respectively. Our study proves the predominance of Candida yeasts and Aspergillus as the fungal agents involved in MOE. Mycological diagnosis allows the identification and antifungal susceptibility testing. Thus, it allows usingof the appropriate antifungal treatment and improves the prognosis of the disease.