Trichophyton indotineae in Virginia: diagnostic identification and case report.

BACKGROUND

Trichophyton indotineae is an emerging Trichophyton species associated with extensive dermatophytosis frequently demonstrating terbinafine resistance. While early cases were reported in South Asia, T. indotineae has since spread globally, with several cases reported in the United States since 2023. To our knowledge, we describe the first cases reported in Virginia.

CASE SUMMARY: Patients A and B each presented to the dermatology clinic with a diffuse, pruritic rash unresponsive to previous courses of topical and antifungal therapy. Both presentations raised concern for T. indotineae infection, which was confirmed with internal transcribed spacer (ITS) genome sequencing of isolates from the lesions. Both patients were initially prescribed an 8-week course of itraconazole 200 mg daily. Patient A required an additional month of treatment, but both patients had improved at follow-up.

CONCLUSION

The present cases highlight several key points regarding the epidemiology, diagnosis, and management of T. indotineae infections, including continued expansion within the US, the need for ITS sequencing to distinguish T. indotineae from Trichophyton mentagrophytes and Trichophyton interdigitale, and the growing role of oral itraconazole as first-line therapy.