Laser Care For Onychomycosis: Can It Be Effective?
- Volume 23 - Issue 5 - May 2010
- 55496 reads
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Candida species have emerged as second-line pathogens. Onychomycosis due to Candida (candidal onychomycosis) occurs increasingly in individuals who have defective immunity.9 Such immunity can be consequential to aging, diabetes, vascular diseases, HIV infection and drug therapies such as immunosuppressive therapy and broad-spectrum antibiotics. Non-dermatophyte mold infections are becoming more prevalent with the Aspergillus and Fusarium species commonly isolated.10
What Are The Current Treatment Options?
Onychomycosis is a difficult condition to treat. There are multiple therapeutic modalities including surgical removal of the nail as well as chemical, topical and oral methods. Dermatophyte infection of the nails is very difficult to eradicate due to the hard, protective nature of the nail plate. Once infection has established itself in the underlying surface of the nail above the nail bed, treatment becomes very difficult.
Advances in oral therapy have contributed to improved treatment outcomes for patients. Generally, oral therapy demonstrates better outcomes. However, patients often prefer topical treatment over oral medication once one informs them of the potential side effects and complications associated with oral antifungal therapy. While the risk of liver failure following the use of oral therapy is likely far less prevalent than the fear generated from the use of the medication, patients often reject the treatment as they consider the risk associated with the complication far worse than the condition itself.
Ciclopirox nail lacquer (Penlac, Sanofi Aventis) is the only FDA approved topical medication in the treatment of onychomycosis. Topical antifungal nail lacquers can deliver the antifungal agent directly to the nail unit.
A recent study evaluated patients with distal and lateral subungual toenail onychomycosis who used ciclopirox nail lacquer once daily for nine months.11 Every week, patients removed the nail lacquer using acetone. The investigator recorded clinical nail status, KOH examination and mycological cultures at baseline, three, six and nine months. Trichophyton rubrum was the most common pathogen.
At the end of the study, good improvement to complete cure occurred in 13 of 36 patients (36 percent), 12 patients showed only mild to moderate improvement and 11 patients (31 percent) had no clinical improvement. Researchers noted no adverse effects throughout the treatment period.
Researchers have also investigated photodynamic therapy (PDT) as a treatment modality for onychomycosis. This treatment uses a drug called a photosensitizer or photosensitizing agent and a particular type of light.12 When photosensitizers are exposed to a specific wavelength of light, they produce a form of oxygen that kills nearby cells.13
In vitro studies have demonstrated that Trichophyton rubrum is able to metabolize 5-aminolevulinic acid (ALA) to protoporphyrin IX and that photodynamic therapy leads to significant reduction in its growth.14
Researchers demonstrated that ALA-PDT provided a cure rate of 43.3 percent 12 months after treatment. This cure rate reduced to 36.6 percent 18 months after treatment.15
Combination therapy consisting of periodic nail debridement and the application of topical medication along with the use of an oral antifungal agent would provide the greatest rate of eradication of the infection.16-18
What The Literature Reveals About Laser Treatment
A search of the literature fails to provide evidence-based support for the use of laser treatment in the management of onychomycosis. While physicians and patients alike would welcome the prospect of a non-invasive treatment for the eradication of onychomycosis, there exists little research to substantiate the claims of the companies developing the technology and those in the medical community who have embraced this technology. This is not to say that research has not been completed. There are studies underway to determine if this is an effective treatment modality.