[Onychomycosis in children and adolescents-case report and overview of the literature].

Fungal nail infections in children and adolescents are on the rise worldwide. Diagnosis and, above all, treatment is a challenge. A 15-year-old girl had been suffering from onychomycosis of the toenails for more than 6 years, and later also of a fingernail on her right hand. Trichophyton (T.) rubrum had already been identified by culture and polymerase chain reaction (PCR) as the pathogen years ago. However, treatment attempts with topical antimycotics and fluconazole did not lead to a cure. Mycological diagnostics using PCR and sequencing of the ITS (Internal Transcribed Spacer) region of the rDNA of the dermatophyte confirmed the diagnosis of tinea unguium caused by T. rubrum. Ciclopiroxolamine-containing water-soluble nail varnish and oral terbinafine were used for treatment, both in off-label use and with the consent of the girl's parents. Terbinafine was given continuously once daily and subsequently intermittently once weekly. After 7 months of combined antifungal therapy, the nail mycosis of the fingernails and toenails healed completely. The endpoint of the therapy was clinical healing and negative PCR for T. rubrum. There have been no recurrences over the past more than 3 years-first under prophylaxis with the antifungal nail varnish.