Efficacy of lasers for the management of dermatophyte toenail onychomycosis

Background: Onychomycosis is a chronic fungal nail infection caused predominantly by dermatophytes, and less commonly by non-dermatophyte molds (NDMs) and Candida species. Onychomycosis treatment includes oral and topical antifungals, the efficacy of which is evaluated through randomized, double-blinded, controlled trials (RCTs) for USA FDA approval. The primary efficacy measure is complete cure (complete mycological and clinical cure). The secondary measures are clinical cure (usually {less than or equal to}10 % involvement of target nail) and mycological cure (negative microscopy and culture). Some lasers are FDA-approved for the mild temporary increase in clear nail; however, some practitioners attempt to use lasers to treat and cure onychomycosis. Methods: A systematic review of the literature was performed in July 2020 to evaluate the efficacy rates demonstrated by RCTs of laser monotherapy for dermatophyte onychomycosis of the great toenail. Results: RCTs assessing the efficacy of laser monotherapy for dermatophyte toenail onychomycosis are limited. Many studies measured cure rates via nails instead of patients, and performed only microscopy or culture, not both. Only one included study reported mycological cure rate in patients as negative light microscopy and culture (0%). The combined clinical cure rates in short- and long-pulsed laser studies were (13.0-16.7% and 25.9%, respectively). There was no study that reported the complete cure rate, however, one did report treatment success (mycological cure (negative microscopy and culture) and {less than or equal to}10% clinical involvement) in nails as 16.7%. Conclusions: The effectiveness of lasers as a therapeutic intervention for dermatophyte toenail onychomycosis is limited based on complete, mycological, and clinical cure rates. However, it may be possible to use different treatment parameters or lasers with a different wavelength to increase the efficacy. Lasers could be a potential management option for older patients and onychomycosis patients with coexisting conditions such as diabetes, liver and/or kidney diseases for whom systemic antifungal agents are contraindicated or have failed.

Corresponding Author; email: AGupta@mediproberesearch.com