Keratinophilic fungal infections in dermatology outpatients from a tertiary care hospital in Southern Rajasthan

Materials & Methods

This cross-sectional, observational study was carried out over one year (July 2020-June 2021) in department of Microbiology, Geetanjali Medical College & Hospital, Udaipur, Rajasthan, India, a tertiary care hospital from southern Rajasthan. Ethical approval for the study was obtained from the Institutional Human Research Ethics Committee. Written informed consent was taken from all the participants prior to enrolment. Patient confidentiality and data privacy were maintained in accordance with ICMR guidelines and the Declaration of Helsinki.

Results

Out of 70 total samples, 65 (92.3%) were positive for dermatophytes (either on culture or KOH), while 5 (7.7%) samples were negative. Samples from male comprised 58.6 per cent, while females accounted for 41.4 per cent, showing a statistically significant male predominance [P=0.043; 95% confidence interval (CI): 47.2-69.5% for males]. The highest number of cases occurred in the 21-30 yr age group (21.6%), followed by the 31-40 yr group (19.6%). The maximum number of samples collected were skin scrapings (52, 73.8%), with a positivity rate of 98.07 per cent, followed by nail clippings (13, 18.5%) with 84.6 per cent positivity, and epilated hair (5, 7.7%) with 60 per cent positivity. On the basis of anatomical sites affected, the most common clinical manifestation was Tinea corporis (64.6%), followed by Tinea cruris (14.5%) (Table). Among the 65 isolates of dermatophytes, 62 (95.4%) belonged to the Trichophyton species, with Trichophyton rubrum (46.2%) being the predominant species (Fig. 1).

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Fig. 1.

Distribution of fungal isolates among the dermatophyte group (n=70).

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The incidence of dermatophytosis was highest among the low-income group (n=42, 60%), followed by the middle-income group (n=22, 30.6%) and the high-income group (n=6, 9.4%). The majority of cases were reported during the summer season (50%), followed by the monsoon season (28.7%). Occupation-wise distribution showed that labourers (n=24, 34.3%) and farmers (n=18, 25.7%) had the highest infection rates. Distribution of dermatophytosis cases in relation to personal history revealed contributing factors such as sharing of fomites, wearing ill-fitting garments, and infrequent bathing (Fig. 2).

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Fig. 2.

Distribution of laboratory confirmed dermatophytosis in relation to personal history.

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Discussion

In the present study, out of 70 samples from suspected cases of dermatophytosis, 65 (92.3%) were positive – 85.8 per cent by culture and 89 per cent by KOH mount. These findings are comparable to studies conducted by Penmetcha et al⁶ (88.8% KOH, 75.2% culture), Almayehu et al⁴ (93.8% KOH, 76% culture) in 2016, and Mandava et al¹⁰ (71.6% KOH, 60.5% culture) in 2019. These results support the increasing trend in dermatophytic infections and suggest that KOH mount is a reliable screening tool for dermatophyte detection.

Male predominance noted in the present study is similar to that reported earlier^11-13. This can be attributed to occupational exposure, increased outdoor activity, and higher levels of sweating in hot and humid conditions. The majority of dermatophytosis cases were observed in the 21-30 yr age group (21.6%), consistent with earlier studies^14,15. This age group is often engaged in outdoor work, which, along with increased perspiration, creates an ideal environment for dermatophyte growth. Tinea corporis was the predominant clinical presentation in the current study (64.6%), followed by Tinea cruris (14.5%), which is similar to findings by Ramaraj et al⁷ (63.2%), Mandava et al¹⁰ (46.1%) and Santosh et al¹⁶ (40.9%). These clinical forms are typically symptomatic, prompting patients to seek early medical attention.

Trichophyton rubrum emerged as the most common isolate in our study, which is in agreement with reports by Ramaraj et al⁷, Penmetcha et al⁶, and Veena et al¹⁷ who documented T. rubrum as the predominant species with frequencies of 58.1 per cent, 48.9 per cent, 37.6 per cent, and 33.8 per cent, respectively. The predominance of T. rubrum may be attributed to its persistent infection patterns and its ability to adapt to human skin. In contrast, Gupta et al¹⁵ reported T. verrucosum (35.5%) as the most common isolate, likely due to geographic and climatic variation.

Previous studies have also reported that majority of dermatophytic infections occurred in the low-income group, similar to our result^7,16,18. The higher incidence in lower socioeconomic populations may be attributed to poor hygiene, overcrowded living conditions, shared fomites, barefoot walking, contact with infected animals or soil, inadequate nutrition, limited disease awareness, exposure to extreme environmental conditions, and lack of education regarding sanitation.

This study has a few limitations. The sample size was relatively small, which may not be representative of the broader population. Molecular diagnostic techniques such as PCR were not employed to confirm species-level identification, potentially limiting diagnostic accuracy. Antifungal susceptibility testing was not performed, which restricts insights into resistance patterns among dermatophytes.

Public health interventions, including awareness campaigns focused on personal hygiene, early diagnosis, and education about risk factors – especially in rural and underserved populations – should be prioritised. Strengthening diagnostic capacity at the primary care level and ensuring accessibility to antifungal therapies can further support effective disease management and control.