Mycological and Clinical Profile Along With Antifungal Susceptibility Pattern of Dermatophytosis in a Tertiary Care Hospital From Western India

Abstract

Introduction:Dermatophytosis is a common superficial mycosis causing significant cutaneous morbidity. In recent times, the prevalence of dermatophytosis is increasing. The dermatophyte infections spread easily and rapidly especially in low socioeconomic classes and thus warrant early therapy.Dermatophyte infections are commonly treated by topical antifungal drugs like clotrimazole, terbinafine, ketoconazole. But severe and chronic form of dermatophytosis requires treatment with systemic antifungal drugs like itraconazole, griseofulvin and terbinafine.There is emergence of antifungal resistant strains due to incongruous use of antifungals and poor antifungal policy. There are limited studies related to antifungal susceptibility testing (AFST). So present study was undertaken to determine mycological, clinical profile and antifungal Susceptibility testing ofdermatophytosis. Material & Methods: A prospective study was conducted on patients with superficial fungal infections over a period of 11 months (October 2018 to August 2019). Various samples like skin scrapings, scales, hair and nail clippings were processed by standard fungal culture methods. AFST was performed by using E-test strips (HiMedia) of fluconazole, itraconazole and terbinafine on Sabourauds dextrose agar plates and interpreted according to CLSI (M38A). Results: A total of 25 (23.8%) dermatophytes were isolated from 105 (skin 57, Nail 41, scales 11, Hair 6) samples. Out of 25 culture positive patients, 18 presented as tineacorporis, 3 as tineacruris, 3 onchomycosis, 1 each as tineacapitis&tinea incognito. T. tonsurans was most common dermatophyte 40% (N10), followed by T. rubrum 36% (N9), T. mentagrophytes 12% (N3) and M. canis 8% (N2) and T. megninii 4% (N1). AFST of all 25 isolates revealed that 21 isolates were sensitive to itraconazole (0.023 to 0.75 mcg/ml) wheras a single isolate of T. rubrum and T. tonsurans each were resistant. Two isolates of T.tonsurans showed lower MICs for itraconazole (0.023mcg/ml). For terbinafine (0.002-0.008mcg/ml), 14 isolates (56%) showed resistance with MICs >32 mcg/ml. For fluconazole (range 0.5-4 mcg/ml) only 3 isolates showed MIC in range while22 were resistant MICs >256mcg/ml. The results were communicated with dermatologists and appropriate changes were made in patient therapy. Conclusion: The emergence of resistant dermatophytesemphasises the need of antifungal drug susceptibility tests, antifungal stewardship and strong antifungal policy to enable the clinician to start suitable antifungals to avoid antifungal resistance and treatment failure.