Efficacy of laser treatment for onychomycotic nails: a systematic review and meta-analysis of prospective clinical trials

[Dermatomycoses: topical and systemic antifungal treatment]

Topical antifungals with activity against dermatophytes include amorolfine, allylamines, azoles, ciclopiroxolamine, and tolnaftate. Polyene antimycotics, such as amphotericin B and nystatin, alternatively, miconazole are suitable for yeast infections of the skin and mucous membranes. For severe yeast infections of the skin and mucous membranes, oral triazole antimycotics, such as fluconazole and itraconazole, are used. Pityriasis versicolor is treated topically with antimycotics, and in severe forms also orally with itraconazole, alternatively fluconazole. Terbinafine, itraconazole and fluconazole are currently available for the systemic treatment of severe dermatophytoses, tinea capitis and onychomycosis. In addition to proven therapeutic regimens, unapproved (off-label use) intermittent low-dose therapies are increasingly being used, particularly in onychomycosis. Oral antimycotics for the treatment of tinea capitis and onychomycosis in children and adolescents can only be used off-label in Germany. In general, any oral antifungal treatment should always be combined with topical antifungal therapy. In tinea corporis and tinea cruris caused by Trichophyton (T.) mentagrophytes ITS (internal transcribed spacer) genotype VIII (T. indotineae), there is usually terbinafine resistance. Identification of the species and genotype of the dermatophyte and resistance testing are required. The drug of choice for T. mentagrophytes ITS genotype VIII dermatophytoses is itraconazole. In individual cases, treatment-refractory onychomycosis may be due to terbinafine resistance of T. rubrum. Here too, resistance testing and alternative treatment with itraconazole should be considered. Therapy monitoring should be carried out culturally and, if possible, using molecular methods (polymerase chain reaction). Alternative treatment options include laser application, and photodynamic therapy (PDT).

Efficacy of Laser Therapy in Comparison With Other Methods for the Treatment of Onychomycosis: A Systematic Review and Meta-Analysis

Onychomycosis, a fungal infection of the nails, presents a significant challenge in clinical management due to its chronic nature and resistance to conventional therapies. This study aims to evaluate the efficacy of laser therapy in treating onychomycosis compared to traditional methods such as terbinafine. A systematic review and meta-analysis were conducted to analyze existing literature on the subject. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) diagram illustrates the selection process of studies. Findings suggest that laser therapy demonstrates promising results in the treatment of onychomycosis, with comparable efficacy to terbinafine and fewer adverse effects. Further large-scale randomized controlled trials are warranted to validate these findings and establish laser therapy as a standard treatment option for onychomycosis.

A focused review on laser- and energy-assisted drug delivery for nail disorders

The purpose of this review is to consolidate and summarize laser-assisted drug delivery (LADD) for nail diseases, particularly onychomycosis and psoriasis. A PubMed search was conducted in June 2023 using search terms (1) "laser assisted drug delivery" AND "nail," (2) "laser" AND "nail," and (3) "nail disorder" AND "laser treatment." References of papers were also reviewed, yielding 15 papers for this review. Fractional ablative CO2 laser (FACL) and Er:YAG laser can be used for LADD of topical medications such as amorolfine, terbinafine, and tioconazole to treat onychomycosis. A fungal culture should be performed to determine the type of dermatophyte, which will help determine which topical will be most effective. Laser settings varied between studies, but overall LADD tended to be more effective than topical treatments alone. Laser-assisted photodynamic therapy (PDT) was also found to be effective in treating onychomycosis. For psoriatic nails, LADD was used to deliver calcipotriol-betamethasone dipropionate foam, tazarotene, triamcinolone, or methotrexate into the nail. Again, LADD was found to be significantly more effective than topical treatment alone. FACL was the only laser noted for use for LADD in both diseases. Laser-assisted drug delivery for nail disease is a newer approach for onychomycosis and nail psoriasis with several benefits and drawbacks. Dermatologists should discuss the option of LADD with their patients who have recalcitrant onychomycosis or nail psoriasis.

Efficacy of laser therapy combined with topical antifungal agents for onychomycosis: a systematic review and meta-analysis of randomised controlled trials

INTRODUCTION

Onychomycosis is a common fungal infection of the nail. Laser and topical antifungal agent combination therapy is an emerging treatment for onychomycosis. The objective of this study was to systematically evaluate the efficacy and safety of laser and topical antifungal agent combination therapy for onychomycosis.

METHODS

The PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, Wanfang and VIP databases were searched from inception to November 2021. Randomised controlled trials (RCTs) on laser therapy combined with topical antifungal agents for onychomycosis were included. The Cochrane Collaboration tool was used to assess the risk of bias, and Revman 5.3 software was used in the meta-analysis.

RESULTS

Twelve studies involving 869 patients were included in this meta-analysis. The results showed that compared with topical antifungal agents alone, laser and topical antifungal agent combination therapy was superior in terms of the complete cure rate (RR 6.04,95% CI (2.17, 16.85), P = 0.0006), mycological cure rate (RR 1.27, 95% CI (1.10, 1.48), P = 0.001), clinical effective rate (RR 1.38, 95% CI (1.20, 1.57), P < 0.00001) and patient satisfaction rate (RR 1.47,95% CI (1.17, 1.84), P = 0.0009).The subgroup analysis of outcome indicators, including mycological cure rate and clinical effective rate, demonstrated that both carbon dioxide (CO₂) laser therapy combined with topical antifungal therapy and 1064-nm neodymium-doped:yttrium aluminium garnet (Nd:YAG) laser therapy combined with topical antifungal therapy showed better results than topical antifungal therapy alone. No adverse events were identified except for three studies reporting transient burning sensation without treatment and mild to moderate pain, both of which were well tolerated.

CONCLUSION

The present study indicated that laser and topical antifungal agent combination therapy is effective for onychomycosis. However, more large-scale and well-designed RCTs are warranted.

Fractional CO2 laser ablation leads to enhanced permeation of a fluorescent dye in healthy and mycotic nails-An imaging investigation of laser-tissue effects and their impact on ungual drug delivery

Purpose

Conventional oral antifungal therapies for onychomycosis (OM) often do not achieve complete cure and may be associated with adverse effects, medical interactions, and compliance issues restricting their use in a large group of patients. Topical treatment can bypass the systemic side effects but is limited by the physical barrier of the nail plate. Ablative fractional laser (AFL) treatment can be used to improve the penetration of topical drugs into the nail. This study visualized the effects of laser ablation of nail tissue and assessed their impact on the biodistribution of a fluorescent dye in healthy and fungal nail tissue.

Methods

For the qualitative assessment of CO₂ AFL effects on healthy nail tissue, scanning electron microscopy (SEM), coherent anti‐Stokes Raman scattering microscopy (CARS‐M), and widefield fluorescence microscopy (WFM) were used. To quantitate the effect of laser‐pretreatment on the delivery of a fluorescent dye, ATTO‐647N, into healthy and fungal nail tissue, ablation depth, nail plate thickness, and ATTO‐647N fluorescence intensity in three nail plate layers were measured using WFM. A total of 30 nail clippings (healthy n = 18, fungal n = 12) were collected. An aqueous ATTO‐647N solution was directly applied to the dorsal surface of 24 nail samples (healthy n = 12, fungal n = 12) and incubated for 4 hours, of which half (healthy n = 6, fungal n = 6) had been pretreated with AFL (30 mJ/mb, 15% density, 300 Hz, pulse duration <1 ms).

Results

Imaging revealed a three‐layered nail structure, an AFL‐induced porous ablation crater, and changes in autofluorescence. While intact fungal samples showed a 106% higher ATTO‐647N signal intensity than healthy controls, microporation led to a significantly increased fluorophore permeation in all samples (p < 0.0001). AFL processing of nail tissue enhanced topical delivery of ATTO‐647N in all layers, (average increase: healthy +108%, fungal +33%), most pronounced in the top nail layer (healthy +122%, fungal +68%). While proportionally deeper ablation craters correlated moderately with higher fluorescence intensities in healthy nail tissue, fungal samples showed no significant relationship.

Conclusion

Fractional CO₂ laser microporation is a simple way of enhancing the passive delivery of topically applied ATTO‐647N. Although the impaired nail plate barrier in OM leads to greater diffusion of the aqueous solution, AFL can increase the permeability of both structurally deficient and intact nails.

Noninvasive Assessment of Mycotic Nail Tissue Using an Ultraviolet Fluorescence Excitation Imaging System

BACKGROUND AND OBJECTIVES

Mycological diagnosis of onychomycosis is based on direct microscopy using external fluorophores to visualize fungal tissue in nail samples and agar culture. Ultraviolet fluorescence excitation imaging (u-FEI) has shown potential in monitoring biological processes by exploiting variations in autofluorescence. This study aimed at assessing the potential of a handheld u-FEI system as a practical screening tool for fungal nail infections.

STUDY DESIGN/MATERIALS AND METHODS

Ninety samples from 29 patients with microscopy-confirmed fungal infection and 10 control samples from healthy participants were collected (n = 100). Using a prototype u-FEI system (single bandpass 25 mm filter with a central pass wavelength of 340 nm and a bandwidth of 12 nm, 295 nm excitation flash, resolution of 640 × 480), images of all samples were acquired under standardized conditions. Average and maximum fluorescence intensity image values in arbitrary units (AU) of manually delineated regions of interests were quantitated and statistically assessed for significant differences between healthy and mycotic samples.

RESULTS

UV-images clearly depicted all 100 nail samples, with a visibly stronger signal in infected samples. Statistically significant differences (P < 0.05) in signal intensity between mycotic samples and healthy controls were observed for maximum and average fluorescence values. Mean fluorescence values of onychomycotic samples showed 23.9% higher maximum (mycotic: 34.9 AU [standard deviation [SD] 4.7]; healthy: 28.2 AU [SD 1.9]) and 10.2% higher average (mycotic: 27.6 AU [SD 2.0]; healthy: 25.0 AU [SD 0.7]) signal intensity values. Receiver operating characteristic curves demonstrated excellent discriminatory ability (area under the curve > 0.9). Analysis of fluorescence measurements of the reference standard demonstrated very low variation (coefficient of variation = 0.62%) CONCLUSION: Quantitation of u-FEI intensities enables differentiation between healthy and mycotic nail samples, constituting a potential point-of-care tool for cost-effective screening for onychomycosis at a primary care level. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.