Clinico-mycological study of dermatophytic infections and their sensitivity to antifungal drugs in a tertiary care center.

BACKGROUND: Worldwide, dermatophytic infections are running a chronic course either due to ineffective treatment or emerging drug resistance. In the past three decades, there has been an increase in incidence and non-responsiveness to conventional antifungals, which suggests that there is a need of antifungal sensitivity testing.

AIMS: This study was aimed at identifying clinico-mycological pattern of dermatophytic infections in patients attending thedermatology outpatient department of a tertiary care hospital, and to obtain the sensitivity pattern of isolates against six commonly used oral antifungals (fluconazole, terbinafine, itraconazole, ketoconazole, griseofulvin and voriconazole).

METHODS: Patients with suspected dermatophytoses attending the outpatient department of Sir Sunderlal Hospital, Varanasi, were enrolled in the study. A detailed history, clinical examination and sample collection for mycological examinations was done. In vitro antifungal sensitivity testing was done on species isolated from culture as per the Clinical and Laboratory Standard Institute M38-A standards, with broth microdilution method.

RESULTS: There were 256 patients recruited in the study, with a male: female ratio of 3:1. The most commonly affected age group was 20-40 years (52.4%). Tinea corporis et cruris was the most common type observed (27.2%). Potassium hydroxide positivity was seen in 211 samples (79.6%) and culture positivity was found in 139 samples (52.4%). The most common species identified was Trichophyton mentagrophytes (75.9%). Sensitivity testing was done on fifty isolates of T. mentagrophytes. Minimum inhibitory concentrations of itraconazole, ketoconazole, terbinafine and voriconazole were comparable, while griseofulvin showed the highest minimum inhibitory concentration. Itraconazole was found to be the most effective drug, followed by ketoconazole, terbinafine and fluconazole. Griseofulvin was the least effective drug among the tested antifungals.

LIMITATIONS: This is a hospital-based study, and may not reflect the true pattern in the community. Sensitivity pattern of only one species T. mentagrophytes was carried out.

CONCLUSION: Inadequate and irregular use of antifungal drugs has led to the emergence of resistant strains, which cause poor treatment outcomes. Thus, it is very important to test for antifungal sensitivity to check for resistance to antifungals.