A Clinical-Mycological Study of Dermatophytosis in Western India with Focus on Antifungal Drug Resistance as a Factor in Recalcitrance

Indian J Dermatol. 2023 Mar-Apr;68(2):234. doi: 10.4103/ijd.ijd_999_22.

Abstract

Background: Dermatophytosis have assumed epidemic proportions in India. Antifungal drug resistance solely cannot explain disease magnitude and changing epidemiology.

Objectives: Aim of this study was to analyse clinical-mycological aspects of dermatophytosis, and estimate contribution of drug resistance in clinical recalcitrance.

Methods: This single-centre observational, cross-sectional, descriptive study was done in tertiary centre of western India after ethical approval, enrolling dermatophytosis patients of all ages and sex. After history and examination, KOH mount and culture in modified SDA medium was done. Culture positive isolates were subjected to E-strip antifungal susceptibility method to test MIC for Terbinafine, Itraconazole, Fluconazole and Griseofulvin.

Results: Total 300 patients were included, with mean age of 33.83±27.5 years and male-to-female ratio of 1.22:1; tinea corporis et cruris being commonest, 39.33% (n=118). Only 11.67% (n=35) were treatment naïve, having classical annular morphology. History of topical steroid abuse was found in 81.67% (n=245), with pseudoimbricate lesions in 70.61% (n=173). 86.67% (n=260) had KOH positivity while 83.33% (n=250) had culture positivity: Trichophyton mentagrophytes 45.6% (n=114), followed by Trichophyton rubrum in 34.4% (n=86). A total of 265 patients fit into definition of recalcitrance, from which 12.45%, i.e., 33 isolates showed in-vitro fluconazole resistance. 14.33% (n=43) cases were chronic, 37% (n=111) persistent, 46% (n=138) recurrent while 17% (n=51) had relapse in their disease course. Steroid abuse was the commonest denominator.

Conclusion: Role of antifungal resistance in recalcitrant dermatophytosis remains debatable. Stopping steroid abuse, which is often the commonest culprit, with adherence to standard antifungal therapy remains the paradigm in management.

Keywords: Antifungal resistance; E-test; T. mentagrophytes; dermatophytosis.