A Case of Caused by var. from a Degu and Evolution of the Pathogen's Taxonomy.

Background: , an anthropophilic dermatophyte, can cause dermatophytosis in humans and animals with rising zoonotic infections through pets, primarily in Europe. Dermatophytosis from is often misdiagnosed due to its inflammatory symptoms. We report a case of from var. in a Japanese woman, contracted from pet Czech degus.

Case: The 40-year-old patient developed neck papules resembling acne. Initial treatment with topical antibiotics and steroids exacerbated the rash. Fungal elements were not detected by direct potassium hydroxide examination. Skin biopsy confirmed fungal elements in the and hair follicles, and was diagnosed. Oral terbinafine 125 mg was initiated without topical agents. Erythematous papules appeared on her limbs, determined as a trichophytid reaction. After two months, her skin improved significantly. Fungal culture identified var. colonies with a yellowish hue. Mating tests classified the strain as Americano-European race (-) with genotype. This was diagnosed as from var. , likely transmitted from pet Czech degus.

Conclusions: The incidence rate of pet-transmitted cutaneous fungal infections may increase in Japan with the trend to keep exotic pets. Dermatologists must recognize dermatophytosis clinical features from anthropophilic dermatophytes to prevent misdiagnosis and understand evolving nomenclature and pathogenesis.