Light Treatments to Cure Nail Infections
Pathophysiology – Onychomycosis
Fungal infections are common on both fingernails and toenails. This condition
is caused by a group of fungus called dermatophytes.
The dermatophytes are a common short-hand label for a group of three genera
of fungi that commonly cause skin disease of people and animals. These are
the genera Epidermophyton, Trichophyton, and Microsporum.
Trichophyton, Microsporum, and Epidermophyton are the causative agents of
dermatophytosis and infect the hair, skin, and nails. Similar to the other two
genera, Trichophyton is a keratinophilic filamentous fungus. Ability to invade
keratinized tissues and the possession of several enzymes, such as acid
proteinases, elastase, keratinases, and other proteinases are the major
virulence factors of these fungi. Trichophyton rubrum is the commonest
causative agent of dermatophytoses worldwide, and it is able to cause invasive
infections in immunocompromised hosts.
Onychomycosis (OM) refers to a fungal infection that affects the toenails or the
fingernails. It may involve any component of the nail unit, including the nail
matrix, nail bed, or nail plate. Onychomycosis is not life threatening, but it can
cause pain, discomfort, and disfigurement, and may produce serious physical
Symptoms of toenail fungus are quite obvious. The affected nail will get yellow
or brown in color and usually thickens. Foul-smelling debris may get
accumulated under the nail. The nail may crumble and eventually fall off.
Onychomycosis affects people of all races. It affects males more commonly
than females. However, candidal infections are more common in women than
in men. Studies indicate that adults are 30 times more likely to have
onychomycosis than children.
Onychomycosis has been reported to occur in 2.6% of children younger than
18 years but as many as 90% of elderly people.
Onychomycosis is caused by 3 main classes of fungi: dermatophytes, yeasts,
and nondermatophyte molds. Dermatophytes are by far the most common
cause of onychomycosis. Two major pathogens are responsible for
approximately 90% of all onychomycosis cases. T. rubrum accounts for 70%
and Trichophyton mentagrophytes accounts for 20% of all cases.
Risk factors for onychomycosis include family history, increasing age, poor
health, prior trauma, warm climate, participation in fitness activities,
immunosuppression (eg, HIV, drug induced) and occlusive footwear.
Treatment of onychomycosis depends on the clinical type of the
onychomycosis, the number of affected nails, and the severity of nail
involvement . A combination of systemic and topical treatment increases the
cure rate. Because the rate of recurrence remains high, even with newer
agents, the decision to treat should be made with a clear understanding of the
cost and risks involved, as well as the risk of recurrence.
• Topical antifungals
Topical treatments alone are generally unable to cure
onychomycosis because of insufficient nail plate penetration.
Ciclopirox and amorolfine solutions have been reported to
penetrate through all nail layers but have low efficacy when used
• Oral therapy
The newer generation of oral antifungal agents (itraconazole and
terbinafine) has replaced older therapies in the treatment of
onychomycosis. They offer shorter treatment regimens, higher
cure rates, and fewer adverse effects.
To decrease the adverse effects and duration of oral therapy,
topical treatments and nail avulsion may be combined with oral
A common means of treating onychomycosis is to remove the nail completely
and topically apply medication to the underlying nail bed. However, not only is
such treatment cosmetically unsightly, but the fungus which invades the nail
often remains in the matrix of the finger or toe (where the nail is formed) and
the disease reoccurs immediately upon, or during ingrowth of the new nail.
Moreover, because of the aggressive nature of this treatment, the regrown
nails are often deformed in shape.
Although recent progresses in oral antifungal agents have been made,
systematic drug therapy through oral administration has proven to be
relatively unsuccessful because of drug intolerances, the expense of the
medications and low patient compliance. Typically, systemic oral treatment
with antifungal agents requires long term treatment with a potential for toxic
side effects. These drugs can have considerable adverse liver or kidney effects
and medication interactions in special populations such as children, the elderly,
and patients with underlying systemic diseases.
The usefulness of antifungal drugs in treating onychomycosis has been limited
as a consequence of resistance to penetration of the nail or because of limited
access to the nail bed through the nail.
Fungicidal and bactericidal effects of light
The germicidal and fungicidal effects of certain types of light have been
recognized for many years. Treatment for skin diseases using light irradiation
have been researched since the late 1800's, and over the years, a large body
of knowledge concerning germicidal radiation has been developed.
U.S Pat. No. 6090788 shows destruction of fungal infections of the nails using
energies between 5-15 j/cm2 and 500-700 nm wavelengths. The amount of
energy supplied combined with the given wavelength destroy the organism.
U.S Pat. No. 7306620 B2 Shows a method of prevention and treatment of
microbial infections using electromagnetic radiation to inactivate the microbes
thus rendering them harmless.
Light based technologies represent a new way to treat nail infections by
selectively irradiating fungi while leaving the nail and surrounding tissue intact.
The treatment consists of irradiating the affected area long enough and using
enough energies in order to inactivate or kill the fungi. The method utilizes a
germicidal range of light to penetrate the skin and nails sufficiently to
successfully treat infections. Electromagnetic radiation damages the organisms
that cause skin and nail infections and disables their ability to replicate. The
infection is thereby prevented if it has not yet begun and cured if it already
exists. These kind of treatments follow the same principles as other known
techniques to treat fungal and bacterial diseases. Light therapy is applied
externally , killing fungus residing under and around the nail and restoring
normal nail growth. Accordingly, it is said that after the treatment, the ones
who have undergone it experienced relief and generate positive feedbacks.
• Previous researches have demonstrated the effectiveness of blue light at
approximately 470 nm or within a range of 400-500 nm wavelength, in
causing retarded growth and cell death .
• Clinical application of helium neon (632 nm) plus infrared diode laser
GaAIAs (830 nm) and CO 2laser in treatment of onychomycotic nails was
also investigated, and good results were obtained.
• In vitro results have shown good efficacy in onychomycosis treatment
using 530nm wavelength.
Available light based treatments today
• Pin Pointe Laser Technology
The laser operates in a very tight spectrum of the near infra red light. They
claim clinical studies began in November 2007, demonstrating over an 88%
success rate. No articles or clinical/technological information has been
• Noveon – Nomir Medical Technologies
They claim clinical studies demonstrate about a 76% success rate. They use a
dual wavelength of 870 nm + 930 nm, utilizing energy densities of 539 j/cm2,
over 6 minutes. Experimental temperatures did not exceed 40.5 0C (in vitro)
and 380C (in vivo) .
Pateret Clinic uses equipment form a manufacturer that has improved the existing technologies, using a 530 nm
wavelength (F-SR applicator), delivering very high, focused energies, that
exterminate the fungus, without damaging the surrounding tissue.
Before After (after one treatment)
Before After (after three treatments)
5. United States Patent Application Publication, provisional
application, Sep. 2006.
9. United States Patent application publication, Pub. No.
US.2008/0058905 A1. Pub. Date: Mar. 6, 2008.
10. United States Patent application publication, Pub. No. 7306620 B2
Pub. Date: Dec. 11, 2007.