Prospective Efficacy and Safety Evaluation of Laser Treatments With Real-Time Temperature Feedback for Fungal Onychomycosis

November 2013 | Volume 12 | Issue 11 | Original Article | 1237 | Copyright © November 2013


Jill Waibel MD, Adam Jared Wulkan MD, and Ashley Rudnick

Miami Dermatology and Laser Institute, Miami, FL

Abstract
BACKGROUND and OBJECTIVES: Onychomycosis affects five percent of the worldwide population. Onychomycosis is a therapeutic challenge. Current therapies on the market are either ineffective or require patient monitoring. Laser and light technologies are being investigated as a possible treatment option for onychomycosis. The proposed mechanism of action is unknown. All infectious agents may be killed by heat (except prions). One possible theory is the photothermal effect from water absorbing lasers creates bulk heating in the nail plate to kill fungal hyphae. Laser technology may be a promising new treatment option for onychomycosis. This is a prospective trial with real-time temperature feedback to evaluate efficacy and safety of laser therapy for onychomycosis.
METHODS: Twenty-one patients with PAS or culture proven fungal onychomycosis were prospectively treated with laser until target temperature of 46 - 48 degrees Celsius was achieved using real-time infrared temperature feedback. The laser and light therapies used were 1319nm, 1064nm and BroadBand Light. Exclusion criteria included mixed infection and no other prior therapeutic interventions. Subjects received four treatment sessions one week apart. Assessments included PAS & cultures at one, three and six months post treatment. Patients also were asked a pain score from 1-10 during treatment.
RESULTS: Patients tolerated the procedures well with high satisfaction. Average treatment time was 10 minutes. No adverse events were noted. Patients reported mild-moderate transient discomfort during treatment. Six-month culture results revealed 20/21 negative for fungal organisms.
CONCLUSION: Laser therapy offers a safe and effective new option for onychomycosis. This may be the optimal therapy for a large market that needs alternative or adjunct to current therapies. Laser is quick, painless therapy that does not require any oral medications or blood test for monitoring. Additional larger scientific studies are needed to confirm our pilot study results.

J Drugs Dermatol. 2013;12(11):1237-1242.

INTRODUCTION

Onychomycosis refers to a fungal infection affecting the nail plate or the nail bed of the toenails or fingernails.1 It is generally caused by dermatophytes and less frequently by non-dermatophyte molds and yeasts.2 The term dermatophyte refers specifically to fungi related to the genera Trichophyton, Epidermophyton, and Microsporidium, which cause an infection of the skin, hair and nails due to their ability to obtain nutrients from keratinized material.3 They are usually restricted to the non-living cornified layer of the epidermis because of their inability to penetrate viable immunocompetent tissue. However, any component of the nail may be involved, including the nail matrix, nail bed or nail plate.
Onychomycosis is a medical condition with aesthetic side effects for many patients.4 While it is not a life threatening condition, it may lead to serious morbidity, including secondary bacterial infections.2,5 Furthermore, onychomycosis can cause pain, discomfort and may produce serious physical and occupational limitations. The psychosocial and emotional effects are widespread and may have an impact on quality of life.
Approximately 34% of diabetics have onychomycosis.2 Diabetics are at increased risk to develop complications secondary to onychomycosis.5,6,7 Dermatophyte infected nails can form thick, jagged edges that can injure the surrounding skin creating foot ulcers.5,6,8 In diabetics with associated sensory neuropathy ulcerations can go undetected precipitating secondary bacterial complications that can be life threatening (sepsis) or require amputation of the lower extremities. Onychomycosis results in a three-fold increase in relative risk for developing gangrene in diabetic patients,5 creating a treatment imperative.
There are numerous risk factors associated with onychomycosis, including age, family history, male gender, and diabetes (Table 1). Adults are most commonly affected by onychomycosis secondary to slower nail growth. Some individuals are genetically predisposed to onychomycosis.5 The toenails are affected more often than the fingernails, likely due to slower nail growth, increased exposure to organisms and an increased prevalence of injury.5 Additionally, athlete’s foot often precedes toenail infection. The most common fungal infections of the nail