Methodological considerations in keratinophilic fungal infections study

Sir,

I read with considerable interest the article by Vyas et al¹ on keratinophilic fungal infections published in the August 2025 issue of the Indian Journal of Medical Research. The authors deserve credit for addressing a relevant and clinically significant topic. There are, however, several key methodological oversights that limit the generalisability of the findings.

Firstly, although the study defines the sampling period, it does not account for potential seasonal variations in species distribution. The prevalence of keratinophilic fungal infections is widely recognised as being influenced by humidity and temperature, particularly in semi-arid regions such as Rajasthan.² Without consideration of temporal factors, the study does not address how seasonal trends may also influence the reported prevalence and species distribution.

Another important limitation, as acknowledged by the authors, is the reliance solely on morphological identification without molecular confirmation of species. Given the well-recognised morphological overlap among Trichophyton species, the absence of molecular validation (e.g., Internal Transcribed Spacer (ITS) sequencing) may lead to misidentification.³ Although the study opted for morphological identification, it did not address this limitation by reporting on inter-observer reproducibility or fungal identification validation. Incorporating measures of diagnostic accuracy or cross-verification could further strengthen the reliability of the reported species distribution when molecular diagnostic techniques are unavailable.⁴

Furthermore, no data were provided regarding comorbidities such as diabetes, immunosuppression, or atopy- factors shown to predispose individuals to chronic or recurrent dermatophyte infections.⁵ Their omission limits clinical interpretation and the ability to further contextualize the high-risk subgroups identified in this study.

In conclusion, while the article provides valuable baseline data on keratinophilic fungal infections in southern Rajasthan, these unacknowledged methodological and contextual limitations restrict its interpretive and clinical value. Adopting multi-centre, seasonally stratified designs, incorporating molecular diagnostics or species identification validation, and comorbidity data would enhance the reliability, generalizability, and practical applicability of such research.