Extensive tinea corporis and tinea cruris et corporis due to trichophyton interdigitale

Abstract

Background: India is facing a gruesome epidemic-like scenario of chronic, extensive and recalcitrant dermatophytosis for the past 5-6 years. Dermatophytosis, also commonly known as tinea, used to be considered as trivial infection and was easy to treat. Unethical and irrational mixing of antibacterial and topical corticosteroid with antifungal agents has been instrumental for this extremely challenging situation. Applying such topical preparations for the treatment of dermatophytosis, without any oral antifungal agents can result in extensive lesions and also, fungal resistance. Objective: To find out the cause and dermatophyte species associated with the extensive lesions of tinea corporis. Patients and methods: A study was carried out in the tertiary care centre by the Department of Dermatology and Microbiology during the period starting from October 2016 to April 2017. A total of 158 patients were consented. Any patient with clinical findings of Tinea corporis and KOH and/or culture positive was enrolled in the study. A detailed history was taken. Samples were collected after cleaning the part with 70% alcohol and all KOH positive or negative samples were inoculated on Sabouraud’s dextrose agar supplemented with chloramphenicol and cycloheximide. The culture plates were incubated at 25°C and were observed for four weeks. Lacto Phenol Cotton Blue (LPCB) mounts were prepared to study the microscopic structures in detail. Other tests like urease and in vitro hair perforation tests were also set up to differentiate Trichophyton interdigitale from Trichophyton rubrum. Results: A total of 149(94.30%) were KOH and 158 (100%) were culture positive. We isolated only Trichophyton interdigitale from 158 patients. None of the patients was HIV positive, 6patients (4%) had diabetes. About 70% of the patients gave history of using various combinations of antifungal, antibiotic and topical steroid creams and nearly 10% used pure steroid creams. Rest did not know the name of the cream they applied. Limitations: Molecular characterization was not done to see genetic relatedness. Conclusion: Topical steroid lowers the local immunity and contribute to the extensive and atypical lesions. Dermatophytosis has acquired epidemic proportions in this region of western UP. Misuse of unregulated combinations of steroid is rampant in this region.