Tinea capitis favosa misdiagnosed as tinea amiantacea

Favus of the scalp or tinea capitis favosa is a chronic dermatophyte infection of the scalp. In almost cases, favus is caused by Trichophyton schoenleinii, anthropophilic dermatophyte. It is characterized by the presence of scutula and severe alopecia. Besides the classic clinical type of tinea capitis favosa, there are many variant of clinical form which may persist undiagnosed for many years. In this work, we report an atypical form of favus to Trichophyton schoenleinii which was misdiagnosed as tinea amiantacea.

An 11-year old girl came to the outpatient department of dermatology (day 0) with history of tinea amiantacea treated unsuccessfully with keratolytic shampoo (day - 730). She presented a diffuse scaling of the scalp with thick scaly patches and without scutula or alopecia. A diagnosis of tinea favosa by T. schoenleinii was made by mycological examination. She was treated with griseofulvin and ketoconazole in the form of foaming gel for twelve weeks. Despite treatment, clinical evolution was marked by appearance of permanent alopecia patches. The follow-up mycological examination was negative.

Because of ultimate evolution of favus into alopecia, we emphasize the importance of mycological examination in case of diffuse scaling.