Emerging Zoonotic Dermatophytosis: A 10-Year Case Series from a Dermatology Clinic in Japan

We retrospectively analyzed 99 cases of zoonotic dermatophytosis diagnosed by culture over a 10-year period at a dermatological clinic. Microsporum canis was the most frequently isolated species (89 cases), followed by Trichophyton verrucosum (4 cases), T. mentagrophytes (4 cases), T. benhamiae (1 case), and T. erinacei (1 case). Patients < 15 years of age accounted for 31.3% of the cases. Tinea corporis was the predominant clinical form, with frequent facial and upper-extremity involvement. Topical corticosteroid misuse was noted in 37 patients, and multiple family members were affected in 20 cases. M. canis infections were mostly linked to cats, including stray cats and adopted shelter cats. Infections caused by T. benhamiae and T. erinacei were traced to guinea pigs and hedgehogs, respectively. These findings highlight diagnostic challenges and emerging animal reservoirs. The One Health approach requires active surveillance and education across human and animal health.