Treatment of onychomycosis using a 1064-nm diode laser with or without topical antifungal therapy: a single-center, retrospective analysis in 56 patients

S2k guideline: Laser therapy of the skin

This guideline aims to improve the efficiency and safety of lasers and optical radiation sources with similar effects (especially IPL). Laser therapy of skin lesions with an increased amount of melanocytes should be performed with caution. Laser treatment of pigmented melanocytic nevi is not recommended. The guideline contains recommendations regarding the treatment of lentigines and café-au-lait spots, non-pigmented dermal nevi, Becker nevus, nevus of Ota/Hori/Ito and melasma. Further recommendations focus on the treatment of skin lesions without an increased amount of melanocytes (ephelides, postinflammatory hyperpigmentation including berloque dermatitis, seborrheic keratoses, traumatic/decorative tattoos and metallic deposits), hypopigmentation (vitiligo), benign non-pigmented neoplasms (fibrous papule of the nose, nevus sebaceus, epidermal nevus, neurofibroma, sebaceous gland hyperplasia, syringoma, xanthelasma palpebrarum), inflammatory dermatoses (acne papulopustulosa/conglobata, acne inversa, granuloma faciale, lichen sclerosus, lupus erythematosus, psoriasis vulgaris, rosacea, rhinophyma), wrinkles/dermatochalasis/striae, hypertrichosis, scars (atrophic, hypertrophic; keloids, burn/scald scars), laser-assisted skin healing, onychomycosis, precancerous lesions and malignant tumors (actinic keratoses/field cancerization, cheilitis actinica, basal cell carcinoma), vascular skin lesions (angiokeratoma, angioma, hemangioma, malformation, spider veins, granuloma telangiectaticum (pyogenic granuloma), rubeosis (erythrosis interfollicularis colli, ulerythema ophryogenes), nevus flammeus, telangiectasias and Osler's disease (hereditary hemorrhagic telangiectasia) and viral skin lesions (condylomata acuminata, mollusca contagiosa, verrucae planae juveniles/vulgares/ verrucae palmares et plantares).

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 nondermatophyte molds and Candida species. Onychomycosis treatment includes oral and topical antifungals, the efficacy of which is evaluated through randomized, double-blind, controlled trials for US Food and Drug Administration approval. The primary efficacy measure is complete cure (complete mycologic and clinical cure). The secondary measures are clinical cure (usually ≤10% involvement of target nail) and mycologic cure (negative microscopy and culture). Some lasers are US Food and Drug Administration 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 of 2020 to evaluate the efficacy rates demonstrated by randomized controlled trials of laser monotherapy for dermatophyte onychomycosis of the great toenail.

RESULTS

Randomized controlled trials assessing the efficacy of laser monotherapy for dermatophyte toenail onychomycosis are limited. Many studies measured cure rates by means of nails instead of patients, and performed only microscopy or culture, not both. Only one included study reported mycologic 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 (mycologic cure [negative microscopy and culture] and ≤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, mycologic, 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.

Utilization of the 1064 nm Wavelength in Photobiomodulation: A Systematic Review and Meta-Analysis

Introduction: Photobiomodulation or low-level laser therapy (LLLT;<0.5 W) has been used as a non-invasive treatment for various medical indications. Short (visible; 635-650 nm) and longer (invisible; 810-850 nm and 915-980 nm) near-infrared wavelengths have been commonly used, but power setting deficiencies or incorrect wavelength settings can cause negative outcomes. The 1064 nm wavelength as the longest wavelength is a relative newcomer in high-powered (>0.5 W) laser photobiomodulation therapy (HPL-PBMT) with unique biophysical characteristics. Methods: A comprehensive search of 2016-2021 PubMed, Google Scholar, and Cochrane databases for "photobiomodulation" restricted to clinical trials for patients with a medical diagnosis was done. "1064 nm" content was identified and restricted to high-powered lasers (>0.5 watt). Cohen's d was calculated for the effect size and the difference was determined as a measure of relative 1064 nm HPL-PBMT efficacy. Results: The 22 independent studies meeting inclusion criteria focused on knee arthropathies, spine, shoulder/elbow, wound, gynecological, or osteoporosis with evaluation of pain, function, quality of life, range of motion (ROM), and anatomy. Pain was reduced with statistical significance (P<0.05) in 90% of study assessments (n=20) and 100% of studies focused on the knee (n=6). Of 18 studies assessing functional outcome measures, 100% demonstrated statistically significant improvements. Follow-up assessments up to 6 months in 5 knee arthritis studies revealed long-term pain reduction after cessation of treatment. Improvements in wound healing, bone mineral density, and knee cartilage thickness were demonstrated. The largest effect sizes observed were pain reduction in knee arthritis (average Cohen's d effect size=2.46). Conclusion: These studies have established that 1064 nm HPL-PBMT can effectively reduce pain, increase ROM, increase functional scores, and increase the quality of life for knee osteoarthritis and spinal disorders, with limitations. More studies are needed for clinical validation of single-trial data detecting changes in musculoskeletal conditions, cartilage thickness and bone density.

Combined laser and ozone therapy for onychomycosis in an in vitro and ex vivo model

In order to develop a fast combined method for onychomycosis treatment using an in vitro and an ex vivo models, a combination of two dual-diode lasers at 405 nm and 639 nm wavelengths, in a continuous manner, together with different ozone concentrations (until 80 ppm), was used for performing the experiments on fungal strains growing on PDA agar medium or on pig’s hooves samples. In the in vitro model experiments, with 30 min combined treatment, all species are inhibited at 40 ppm ozone concentration, except S. brevicaulis, which didn’t show an inhibition in comparison with only ozone treatment. In the ex vivo model experiments, with the same duration and ozone concentration, A. chrysogenum and E. floccosum showed total inhibition; T. mentagrophytes and T. rubrum showed a 75% growth inhibition; M. canis showed a delay in sporulation; and S. brevicaulis and A. terreus did not show growth inhibition. This combined laser and ozone treatment may be developed as a fast therapy for human onychomycosis, as a potential alternative to the use of antifungal drugs with potential side effects and long duration treatments.

Onychomycosis: An Updated Review

Background: Onychomycosis is a common fungal infection of the nail.

Objective: The study aimed to provide an update on the evaluation, diagnosis, and treatment of onychomycosis.

Methods: A PubMed search was completed in Clinical Queries using the key term “onychomycosis”. The search was conducted in May 2019. The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews published within the past 20 years. The search was restricted to English literature. Patents were searched using the key term “onychomycosis” in www.freepatentsonline.com.

Results: Onychomycosis is a fungal infection of the nail unit. Approximately 90% of toenail and 75% of fingernail onychomycosis are caused by dermatophytes, notably Trichophyton mentagrophytes and Trichophyton rubrum. Clinical manifestations include discoloration of the nail, subungual hyperkeratosis, onycholysis, and onychauxis. The diagnosis can be confirmed by direct microscopic examination with a potassium hydroxide wet-mount preparation, histopathologic examination of the trimmed affected nail plate with a periodic-acid-Schiff stain, fungal culture, or polymerase chain reaction assays. Laboratory confirmation of onychomycosis before beginning a treatment regimen should be considered. Currently, oral terbinafine is the treatment of choice, followed by oral itraconazole. In general, topical monotherapy can be considered for mild to moderate onychomycosis and is a therapeutic option when oral antifungal agents are contraindicated or cannot be tolerated. Recent patents related to the management of onychomycosis are also discussed.

Conclusion: Oral antifungal therapies are effective, but significant adverse effects limit their use.Although topical antifungal therapies have minimal adverse events, they are less effective than oral antifungal therapies, due to poor nail penetration. Therefore, there is a need for exploring more effective and/or alternative treatment modalities for the treatment of onychomycosis which are safer and more effective.

Comparative Study of Traditional Ablative CO2 Laser-Assisted Topical Antifungal with only Topical Antifungal for Treating Onychomycosis: A Multicenter Study

BACKGROUND

The predominance of onychomycosis has been increasing recently. New medications and treatment modalities are being researched for better saturation of the antifungal agents through the nail plate topically because of the low resilience of some patients for the oral antifungal agents. Treatment of onychomycosis, mainly moderate to severe, can be very challenging, expensive, and time consuming.

OBJECTIVE

The objective of this clinical trial is to compare the efficacy and safety of a manually operated ablative CO₂ laser combined with a topical antifungal agent in patients with onychomycosis.

STUDY DESIGN

We conducted an open-label controlled prospective study of 160 eligible patients randomized into control and treatment groups with a 1:1 allocation in the department of dermatology in five different hospitals in Shanghai. It was a 6-month study where both groups were treated with a topical antifungal agent, with the treatment group also receiving ablation by the traditional CO₂ laser once a month for the first 3 months.

RESULTS

The clinical efficacy and mycological cure rate were significantly higher (p < 0.001) for the treatment group. Three (3.75%) patients from the control group and 18 (25%) patients from the treatment group achieved complete nail clearance along with negative potassium hydroxide and negative culture (primary endpoint) results at 24 weeks. Mycological clearance with at least moderate nail clearance (secondary endpoint) for the treatment group was also significantly higher (p < 0.001) for the laser treatment group. The laser treatment was mildly painful but tolerable by the patients. No drug interactions for both groups were encountered.

CONCLUSIONS

The ablative CO₂ laser is a primitive yet effective modality to be considered for the delivery of topical antifungal agents for the management of mild-to-severe onychomycosis. The laser has good tolerance in patients and is a common equipment found in most dermatology units even those without the latest medical technology.

Clinical retrospective analysis of long-pulsed 1064-nm Nd:YAG laser in the treatment of onychomycosis and its effect on the ultrastructure of fungus pathogen

The objective of this study was to analyze retrospectively the clinical efficacy and fungal clearance of long-pulsed 1064-nm Nd:YAG laser for treating onychomycosis and explore the inhibitory effects of laser on the fungus pathogen-induced onychomycosis in vitro. We performed a systematic retrospective analysis of clinical patients (162 effected nails) of onychomycosis treatment applying laser with or without topical ketoconazole ointment and followed up 3 months after treatment. Trichophyton rubrum- and Trichophyton mentagrophytes-induced onychomycosis was irradiated with laser superimposed for different cumulative energy, respectively; then, the areas of fungus colonies and growth curve in different days were showed, and changes in ultrastructures were observed under SEM and TEM. The clinical effective rate and fungal clearance rate in the combined group were higher than those in the laser group; however, there was no significant difference between the two groups. In vitro, the areas of T. rubrum colonies were significantly reduced at days 1, 3, and 5 after irradiation with cumulative laser energy ≥ 6400 J/cm². When irradiated with cumulative laser energy ≥ 25600 J/cm², significant difference in the areas of T. mentagrophytes colonies was found at day 5. And ultrastructure of the two strains before and after laser irradiation was damaged at different degrees. This study confirmed that long-pulsed 1064-nm Nd:YAG laser is effective for treating onychomycosis, and the laser irradiation can inhibit the colony growth of T. rubrum and T. mentagrophytes and change their cellular ultrastructures. The mechanism of laser treatment of onychomycosis may be related to direct damage of fungus pathogen.