IADVL consensus recommendations on Trichophyton indotineae infections: Using modified Delphi method

Trichophyton indotineae has emerged as a significant novel species causing tinea corporis/cruris/faciei, with established endemicity in a few regions and potential for expanding endemic zones in future.

We aimed to develop consensus on disease definitions, diagnosis and treatment of T. indotineae infection.

Relevant literature from 2017 onwards was analysed and presented to the panel of dermatology experts, followed by circulation of a structured Google questionnaire encompassing various aspects of systemic and topical treatment, including special scenarios. Repeat rounds with modified questions were conducted in domains where (75%) consensus was not achieved, till a maximum of three rounds. Disease definitions were arrived at by discussion among clinical experts. Mycological (diagnostic) guidelines were formulated by the expert mycology members through peer review of each other's drafts.

The panel comprised 14 dermatologists, 2 mycologists and 1 pharmacologist. Disease definitions for clinical and research use are presented. KOH smear testing is recommended in clinically doubtful cases, whereas culture, antifungal susceptibility testing and sequencing are recommended for monitoring trends of prevalent species and drug susceptibility in specialized mycology laboratories. A total of 87 therapeutic questions were put to the 14 dermatologists. Key therapeutic recommendations include the use of itraconazole (ITZ) as a first-line systemic agent and terbinafine (TRB) (higher dose) as a second line, switching systemic antifungal in case of inadequate response at 4 weeks, use of prolonged treatment (till cure) and treatment of relapses with the same regimen as used for initial treatment. Recommendations for treatment monitoring and treatment in special scenarios such as paediatric patients, pregnancy, lactation, renal or hepatic dysfunction, cardiac failure and patients on topical/systemic steroids or immunosuppressives are presented.

The panel has made recommendations on clinical and diagnostic aspects of T. indotineae infections, which would improve patient outcomes and foster academic communication and research.