New treatment options for onychomycosis.

Onychomycosis is the most common nail disorder. The causative pathogens are not only dermatophytes in the majority of cases (Trichophyton rubrum and T. mentagrophytes), but also yeasts of the genus Candida and molds. A wide variety of topical antifungal agents are proposed for first-line treatment of superficial onychomycosis, when the matrix is not involved. New treatment options using light were recently introduced, such as thermal lasers, non-thermal lasers, and photodynamic therapy. For thermal lasers, a temperature increase in the nail of around 50 °C seems to be a prerequisite for success. For non-thermal lasers, the clinical data are very debatable and their mechanism of action still remains mysterious. For photodynamic therapy, 5-aminolevulinic acid is used. The therapy consists of exciting protoporphyrin IX with red light that penetrates relatively deeply. Further clinical studies of larger series of patients and with longer follow-up are still needed to reach a definitive conclusion on the value of these devices.