Terbinafine Resistant Trichophyton Indotineae Isolated in Patients With Superficial Dermatophyte Infection in Canadian Patients

Abstract

Background: Trichophyton mentagrophytes type VIII (segregated as Trichophyton indotineae) is a new strain of antifungal resistant Trichophyton spp. that has been found in different countries around the world. This new strain has been found to be resistant to terbinafine.

Objectives: We present the clinical characteristics, diagnosis and treatment approach of Canadian patients with mycology and molecular confirmation of superficial mycosis caused by T. indotineae.

Methods: Mycology testing from cultures and PCR were used to confirm T. indotineae. We collected clinical information from patients with a confirmed diagnosis.

Results: We report eight Canadian patients mainly presenting with extensive superficial mycosis due to T. indotineae. Three patients presented lesions on the face in addition to lesions on their body. Four patients were initially started on itraconazole or fluconazole, one patient was started on topical therapy, and three patients were referred to infectious disease.

Conclusions: This new strain represents a dermatology and public health concern. Treatment guidelines are lacking. We include a practical approach and treatment recommendations for clinicians who will be encountering these emerging cases in Canada while waiting for evidence-based treatment guidelines.

Keywords: Trichophyton indotineae; Trichophyton mentagrophytes type VIII; dermatophyte infection; terbinafine-resistant tinea corporis.