Trichophyton Mentagrophytes Mimicking Scarring Alopecia

The document described a case of a 4-year-old girl with scarring alopecia caused by Trichophyton mentagrophytes, a fungus not typically known to invade hair in vivo. Initially, the diagnosis was challenging due to negative KOH smears and biopsy results, which showed folliculitis and dermal inflammation without fungal presence. Despite this, griseofulvin treatment was initiated based on the potential for tinea, and a fungal culture later confirmed T. mentagrophytes. The treatment led to the resolution of inflammation and hair regrowth over 9 months with minimal scarring. This case highlighted the importance of considering tinea in differential diagnoses for scalp conditions in young children and reinforced the role of fungal culture in diagnosing tinea capitis, even when initial tests are negative.