Failure to respond to standard therapy for onychomycosis could be related to the presence of dormant chlamydospores and arthroconidia within the diseased nail plate which are not resistant to laser irradiation. After series of treatments healthy nail push diseased portion of nail out where it can be cut or scraped as the nail grows out. The laser light works through the nail selectively photo-inactivate fungal pathogens to a depth below the nail tissue surface leaving the surrounding tissue intact.