Consensus recommendations for Trichophyton indotineae: A modified Delphi study

Trichophyton indotineae (T. mentagrophytes genotype VIII) is spreading globally and is often terbinafine resistant. Guidance for diagnosis and treatment remains inconsistent.

We performed a four-round modified Delphi study. A steering group developed a literature-informed, 42-item questionnaire on diagnosis and management. Consensus was predefined as ≥70% agreement.

Thirty-four experts were invited; 20 completed rounds 1 and 2 and 19 completed rounds 3 and 4. Consensus was achieved for 34/42 items (80.95%). The panel advised suspecting T. indotineae infection in patients with extensive or terbinafine-recalcitrant dermatophytosis, particularly those with a history of travel to or residence in endemic regions. For diagnosis, the panel recommended KOH direct microscopy and fungal culture for suspected dermatophyte infection, and PCR (polymerase chain reaction) with species-level discrimination or ITS sequencing for confirmation of T. indotineae. For resistance assessment, SQLE sequencing and antifungal susceptibility testing were preferred where available, particularly after treatment failure. For treating superficial fungal infections caused by T. indotineae, experts recommended oral itraconazole therapy (100-200 mg/day for 6-8 weeks, or longer as clinically indicated), with luliconazole 1% cream as the preferred adjunctive topical option. Oral posaconazole (300 mg/day for 4-12 weeks) can be considered as the salvage therapy following itraconazole failure, keeping in mind antifungal stewardship.

These consensus statements provide practical interim recommendations. Randomized controlled trials are needed to validate outcomes and optimize regimens.