The study aims to investigate the effectiveness of a single application of Er:YAG laser to the nail plate in increasing the efficacy of the amorolfine lacquer used in the treatment of onychomycosis (fungal infection of nails) cause by dermatophyte molds. This clinical trial respective involve 30 subjects with hands or feet distal-lateral subungual onychomycosis (a kind of onychomycosis that does not affect the ungual matrix). The patients will receive treatment for 6 months meanwhile they will be followed up to access efficacy of the treatment by means of the clearance of nail plate infection.