Onychomycosis or toenail fungus is an infection of the nails/toenails that is caused by a group of microscopic organisms called Dermatophytes (Derm=skin and nails Phytes=attracted to or grow within ). These include the most common fungi that cause both athletes foot and nail fungus, and less common yeasts and molds. The fungus has enzymes that break down the nail plate and allow the strands (hyphae) of the organism to penetrate the nail.
Where did toenail fungus come from?
It is theorized that sometime in the late eighteen hundreds, these fungi were transported to the United States from Asia and Africa. The increase in the occurrence of fungal nails is related to our lifestyle, certain diseases that decrease our immune system’s ability to fight infection, and our ever increasing aging populous.
Who gets toenail fungus?
Anyone can get toenail fungus. Today 36 million Americans suffer from this condition.
However, there are several things that can increase your risk.
- The most common cause is chronic exposure through use of closed tight shoes along with cotton socks that retain moisture. Fungus loves warm, moist, dark areas.
- Trauma to the nail—either direct (eg. stubbing injury) or repetitive microtrauma (eg. running in a tight shoe)—can cause damage to the nail plate allowing fungus to get in.
- Lack of clean protective footwear in areas of exposure to other feet, such as at athletic clubs.
- Aging – as people age they are more likely to have trauma to the nail and more opportunity for exposure to fungus.
- Diabetes, HIV, and medications which decrease the strength of the immune system increases the risk of developing a fungal toenail infection.
Are all ugly toenails, fungal nails?
No. Many times ugly, discolored, or misshapen toenails are not caused by fungus. Although nail trauma, aging, illness, and tight shoes often result in nail fungus, sometimes it does not. Dystrophic, distorted nails can sometimes be visually assessed as fungus by a podiatrist, but doctors will often send out toenail clippings to a lab to be analyzed to ensure that nails aren't treated for fungus unnecessarily.
What does it look like and how is it diagnosed?
The most typical presentation is gradual invasion of the nail from the tip extending back, with thickening, brownish to yellowish discoloration, and detachment of the nail. The nail can also be infected from the cuticle outward which is less common and may appear more whitish. It can also appear as a chalky, white, patchy invasion of the whole nail plate. (Here are more photos of nails with toenail fungus.)
In most cases, the diagnosis can be made by your physician’s evaluation. When there’s a question about the clinical appearance, additional testing such as a nail biopsy can be ordered.
There are other disorders that can cause nail changes that mimic fungus. Pitting of the toenails can be seen in patient with psoriasis, seasonal allergies or eczema. Severe trauma or microtrauma can also cause a nail to become thickened permanently, with or without fungus.
How is it treated?
The following treatments have been used to treat toenail fungus with varying levels of success.
- Topicals – Medications that are applied to the surface of the nail may slow the growth of fungus, but are mostly ineffective in eliminating fungus when used alone. These include prescription lacquers, over-the-counter creams, and natural substances such as tea tree oil.
- Oral Medications – Lamisil and Sporanox are two medications that are currently prescribed. They have shown to be 75% effective. Although there has been concern about liver side effects, these effects are rare. When this medication is prescribed, patients need to receive monitoring to ensure that their liver is not affected.
- Laser Treatment – A few years ago the FDA approved the use of certain lasers to treat toenail fungus. Laser treatment is painless, has no long term side effects, and studies have shown a success rate as high as 70%. New clear nail growth can be seen in as little as three months. Nails can be re-treated at three month intervals as needed, without systemic side effects that might be experienced with an oral medication.
One of the keys to success with laser treatment is finding a podiatrist that includes a fungal toenail prevention program. This involves education about how to prevent re-infection, including hygiene tips, products for sterilizing shoes, use of anti-fungal creams, and other solutions which can increase the efficacy of laser treatment.
Learn more about our Laser Treatment Program.
Why treat toenail fungus?
There are many reasons for treating onychomycosis.
- The nails are ugly, thick and hard to trim
- The disease is contagious
- The fungus causes the nail to lift at the end, making them subject to secondary trauma from catching on socks and tearing
- Thick nails can become painful, and require special and frequent care to thin them
- Thick nails often become ingrown, infected, and may require surgery
- In the diabetic or otherwise immunosuppressed patient, there is an increased risk of ulcerations and infections underneath the nail. According to one study, diabetic patients with nail fungus have a three times greater rate of developing ulcers than those without toenail fungus. These can become limb threatening.
Fungus is everywhere. Here are some steps you can take to avoid getting a nail fungus infection.
- Exercise proper hygiene and regularly inspect your feet and toes.
- Keep your feet clean and dry.
- Wear shower shoes in public facilities whenever possible.
- Clip nails straight across so that the nail does not extend beyond the tip of the toe.
- Use a quality foot powder (talcum, not cornstarch) in conjunction with shoes that fit well and are made of materials that breathe.
- Avoid wearing excessively tight hosiery, which promotes moisture. Socks made of synthetic fiber tend to "wick" away moisture faster than cotton or wool socks, especially for those with more active lifestyles.
- Disinfect home pedicure tools and don't apply polish to nails suspected of infection.
Whether a cosmetic problem, a potentially infective or a painful one, developing a safe and effective program for onychomycosis is the specialty and responsibility of your podiatrist.