Trichophyton tonsurans infections in North Africa: A case series from Tunisia

Dermatophytoses are common superficial fungal infections, most frequently caused by Trichophyton species. Among them, Trichophyton tonsurans is increasingly recognized as an important cause of tinea capitis and other dermatophytic infections. We conducted a retrospective review spanning three- years and six months (January 2022 - June 2025) in the Parasitology-Mycology Laboratory of La Rabta University Hospital (Tunis, Tunisia). The study included patients with dermatophytosis confirmed to be caused by Trichophyton tonsurans. Clinical samples (skin, scalp, nails) were examined by direct microscopy, following potassium hydroxide clarification and cultured on Sabouraud agar with chloramphenicol and with or without actidione at 27 °C. Identification was based on colony morphology, microscopic examinations and confirmed by ITS2 sequencing. Eight cases of T. tonsurans infection were diagnosed during the study period. Patients ranged in age from 8 to 59 years. Seven presented with scaly alopecic patches on the scalp and one with generalized erythematous-squamous lesions associated with onychomycosis. Four patients (three children and one adult) reported similar infections among close contacts, suggesting possible intra-familial or community transmission. Direct microscopy was positive in six cases, revealing endothrix parasitism or septate hyphae. Cultures yielded powdery white to beige colonies with a yellowbrown reverse within 8-14 days. Molecular analysis confirmed the isolates as T. tonsurans. This case series documents the occurrence of T. tonsurans infections identified over a recent three-year period in Tunisia. Accurate laboratory diagnosis and molecular confirmation remain essential for clinical management and for monitoring evolving dermatophyte epidemiology in the region.