Cutaneous Infections Caused by Trichophyton indotineae: Case Series and Systematic Review

Background/Objectives: Dermatophytosis due to Trichophyton (T.) indotineae has spread worldwide, and the acquisition of new drug resistances is making this threat challenging to face. We report four cases of dermatophytosis caused by T. indotineae and perform a systematic review of case reports to explore the most relevant clinical and demographic features and the treatment patterns of this infection. Methods: A literature search, using the PubMed database and following PRISMA guidelines, was performed up to the 6th of December 2024. Articles were included if written in English and presented in the form of case reports/series involving human subjects, with detailed information and T. indotineae infection confirmed by internal transcribed spacer sequencing. Results: Initially, 255 records were identified, and 30 articles were finally selected, including 64 patients, mainly from the Asian continent. Most patients were healthy and/or immunocompetent (65.52%), and the mean disease duration suggested long-lasting lesions. At least two different body sites were generally involved, with a predilection for lower body areas (groins included), as also observed in our patients (all from South Asia). Review results indicated itraconazole as the most commonly prescribed final medication. Treatment with itraconazole led to complete remission in three of our patients (one patient was lost to follow-up). Conclusions: T. indotineae infection should be suspected in case of extensive and/or recalcitrant dermatophytosis, especially in patients with a travel history to Asian countries. Further research is needed to develop rapid, inexpensive, and accurate techniques for the identification of T. indotineae and drug-resistant strains and to define the optimal preventive and treatment strategies.