Clinical and microbiological profile of dermatophytosis: a cross-sectional study comparing diagnostic methods at a tertiary care hospital in Jamnagar, India

Abstract Background: Dermatophytosis, a common superficial fungal infection, is seeing a surge in chronic and recurrent cases across India. Rapid and accurate diagnosis is critical for timely treatment. This study compares the conventional potassium hydroxide (KOH) wet mount with the modified KOH-dimethyl sulfoxide (DMSO) method for the direct microscopic diagnosis of Sabouraud Dextrose Agar (SDA) and dermatophyte test medium (DTM), as well as for culture isolation of dermatophytosis. Aim: To evaluate the prevalence of dermatophytosis and identify the predominant dermatophyte species in a tertiary care hospital in Jamnagar, Gujarat, while assessing the diagnostic accuracy of various techniques. Objectives: To determine the prevalence of dermatophytosis in a tertiary care hospital in Jamnagar. 1. To identify the predominant dermatophyte species responsible for dermatophytosis in the study population. 2. To compare the diagnostic effectiveness of different methods employed in identifying dermatophytes. Materials and Methods: This cross-sectional study was conducted at Shri M.P. Shah Government Medical College, Jamnagar, over 1 year (November 2020–October 2021). A total of 200 clinical samples were collected from patients with dermatophytosis at the Dermatology outpatient department. Inclusion criteria were patients of all ages and genders with clinical signs of dermatophytosis, excluding those on antifungal therapy or unable to complete follow-up. Demographic data, including age, gender, and clinical history, were recorded. Samples (skin, nails, hair) were collected using aseptic techniques and processed via direct microscopy and fungal culture methods for dermatophyte identification. Results: Of 200 suspected dermatophytosis cases, 85 (42.5%) were culture-positive. The highest number of cases and culture positivity occurred in the 21–40 age range, with 57 (28.5%) cases each in the 21–30 and 31–40 groups. Males comprised 128 (64%) of the cases, accounting for 51 (60%) of the culture-positive results. Summer had the highest culture positivity rate, with 68 (80%) positive cases. The most common occupations among culture-positive individuals were farmers (29, 34%) and outdoor laborers (26, 31%). Skin scrapings were the most frequent specimen type, accounting for 144 (72%) specimens and yielding 63 (74%) positive cultures. Tinea corporis was the most common diagnosis, observed in 87 (60%) cases, of which 44 (51%) were culture-positive. DMSO mount showed slightly higher detection rates than KOH (54% vs. 50%), and SDA was more effective than DTM (96% vs. 88%). Trichophyton rubrum was the most frequently isolated species, 40 (47%), followed by Trichophyton mentagrophytes , 30 (35.2%). Conclusion: The 10% KOH + DMSO mount improves clarity and detection rates compared to the conventional KOH mount, offering a rapid and effective screening tool. Culture remains the gold standard for species identification; SDA yields better results than DTM media. Early, accurate diagnosis helps prevent chronic, resistant cases.