NAILS played 20 questions with seven top nail experts to get the answers to your most frequently asked questions about fungal infections of the nails.
Fuad Abuabara, M.D., principal investigator for trials in dermatology at Camino Medical Group in Northern California.
C. Ralph Daniel III, M.D., clinical professor of dermatology at the University of Mississippi Medical Center, Jacksonville.
Boni Elewski, M.D., professor of dermatology at the University of Alabama at Birmingham
Michael Gold, M.D., Dermatology and Dermatologic Surgery at Gold Skin Care Center, Nashville, TN
Charles Lynde, M.D., senior dermatologist at the Lynde Center for Dermatology and associate professor with the Department of Dermatology at the Toronto Hospital in Canada.
Phoebe Rich, M.D., clinical associate professor of dermatology, Oregon Health Sciences University, Portland
Richard Scher, M.D., professor of clinical dermatology for the College of Physicians and Surgeons, Columbia University, New York.
Almost 30 million Americans—approximately 13% of the population—has a fungal infection of the nails (also known as onychomycosis.)
As a percentage of salon clients, though, Richard Scher, M.D., estimates the percentage drops to less than 5%. Even so, questions on onychomycosis have topped nail techs' lists of questions on nail health for NAILS' medical experts over the past decade.
Your questions prompted us to assemble the ultimate nail tech's guide to onychomycosis.
We compiled your most frequently asked questions, added a few of our own, and posed them to seven dermatologists around the country who research, teach, and treat onychomycosis every day. When there was a difference of opinion or additional information, we provided responses from two or more doctors.
If you have more questions about onychomycosis after reading this, send them on. Our experts are standing by.
What are the classic signs and symptoms of onychomycosis?
Dr. Abuabara: The most common changes are a yellow or whitish discoloration of the nail (a longstanding infection may turn the nail brown or black), thickening of the nail, separation of the nail plate from the nail bed, brittle nails, less commonly, redness around the infected nail and loss of the nail.
Dr. Gold: A whitish discoloration usually signifies a yeast infection, while a yellow or brown discoloration usually indicates a dermatophyte infection. Both yeast and dermatophytes are types of fungi. [See "Fungus Unplugged" for a more detailed discussion of these fungi.] However, other organisms, including several bacterial agents, can affect the nails. For example, green indicates a pseudomonas (bacterial) infection, while a black discoloration signifies a proteus infection. If you see what appears to be a superficial white discoloration or yellow/brown discoloration underneath the nail, refuse the service and refer your client to a medical professional knowledgeable about nail diseases, such as a dermatologist.
How and where are most fungal infections of the skin and nails contracted—is the old saw about wearing shoes in public showers really true?
Dr. Lynde: Fungal spores are all around us in the environment. Fungi especially thrive in moist places, so the old saw about gyms and public showers is probably true. But you're equally at risk if someone in your home has a fungal infection because the fungi are in the shower, the carpet, etc.
Dr. Daniel: Developing onychomycosis is usually a long-lasting process where the person has athlete's foot for years then traumatizes the nail, etc. I have, however, had patients who suggested they had gotten other types of infections in a salon.
How—and why—do fungi infect the nails?
Dr. Lynde: Some types of fungi feed on keratin, the dead skin cells that comprise nails. But fungi can't infect healthy nails that have a good vascular supply because fungi also need a warm, moist environment to survive. Some type of trauma usually precedes fungal infections of the nails, whether a person stubs her toe or wears poor-fitting shoes. It often takes four to five months for onychomycosis to become apparent, though, and many people have forgotten the original injury by then.
Why is onychomycosis on the increase in the United States?
Dr. Daniel: People are living longer and are more mobile. Onychomycosis is more common in older individuals: Studies show that less than 1% of pre-teens have onychomycosis. Between 5% and 10% of individuals up to age 30 have onychomycosis, and only 20% of people ages 30-60. In people over age 60, the number jumps to 40%-50%.
People are not only living longer, they're exercising more. Exercise can traumatize the nail and break the seal between the nail plate and nail bed. Studies show that almost 100% of the time the fungal infection starts on the bottom of the feet, moving into the nail unit when that seal is broken.
Who is at risk for onychomycosis?
Dr. Abuabara: The risk factors include diabetes, debilitating disease, or a compromised immune system such as that found in people with AIDS. Other risk factors include poor circulation such as caused by peripheral vascular disease. Also, trauma creates a portal for the fungi to invade the undersurface of the nail. Finally, poor nutrition and hygiene and repeated exposure to infected persons, animals, or surfaces (such as the floor at the local gym) all play a role.
Why are fungal infections found so much more commonly on the toenails than fingernails?
Dr. Rich: True fungal infections of the fingernails are about one-tenth as common as on the toenails. The toenails are exposed to much more trauma and abuse than the fingernails. The feet also are more susceptible to fungal infections of the skin because they spend so much time encased in socks and shoes, which foster the dark, moist environment fungi thrive in.
Can nail techs safely service clients with a fungal infection?
Dr. Lynde: As long as you sterilize or dispose of your implements between clients, you can safely service those with fungal infections without putting others at risk.
As for the infected nail, you can safely file it down, carefully clip it back, and apply polish. Do not apply artificial nails.
Trimming back the nail removes some of the subungual debris—the whitish-yellowish, crumbly material. It also helps prevent clients from catching the separated edge of the nail, which not only hurts, but also can help the fungi spread. Don't, however, dig under the nail to get at this debris. Digging can cause the nail plate to separate from the bed and allow the fungi to move further back under the nail.
Nail polish enhances the living conditions for fungi, but I tell my patients that it takes months for the medicine to work, so it's OK to conceal the condition in the meantime.
Why are fungal infections so difficult to treat successfully?
Dr. Abuabara: Nails grow very slowly, and the medicines available to treat fungal infections primarily arrest the growth of the fungi. Thus, you have to wait for the affected nail to grow out to get rid of the infection. This can take three to six months for the fingernails and up to a year for the toenails.
Dr. Elewski: They're not as hard to treat as they used to be. In the past, the available oral treatments had to be taken every day until the nail completely grew out, and they had low cure rates. The newest oral drugs don't have to be taken as long and they cure 80% of infections. The remaining 20% of infected nails might require a longer course of oral medication or a combination of oral and topical treatments, but 100% of infections can be cured today.
What happens if onychomycosis is left untreated?
Dr. Elewski: It will continue to worsen. It may start on one nail, then spread to a second nail, then to a third, fourth, and fifth. Then it might move to the other foot or to the fingernails. Studies show that about half of people with onychomycosis on their toenails experience pain as the nails thicken.
Dr. Lynde: For the most part onychomycosis is a cosmetic nuisance, but it can spread and you can get secondary infections. Untreated, it can permanently damage affected nails.
Briefly discuss the treatments currently available, along with their advantages and disadvantages.
Dr. Elewski: The medications used to treat onychomycosis are safe and effective. They've been on the market for a long time, and well over 100 million people worldwide have taken them. Some of them are not good for certain people. You should discuss the best choice for your particular needs with your doctor.
Griseofulvin is one of the older drugs used to treat onychomycosis. It's a safe drug that's a standard treatment for fungal infections on the scalp, but its cure rate for onychomycosis is less than 20%.
Today, we have Lamisil and Sporanox as highly effective treatments of onychomycosis. Lamisil is taken just once a day, with or without food, for three months (six weeks for onychomycosis of the fingernails). Sporanox should be taken with food and has some significant drug interactions, but it also is a safe, effective treatment when used correctly.
Diflucan is another oral treatment. The FDA has not approved Diflucan for the treatment of onychomycosis, but it has been approved for that use in other countries and is very safe to use. I find it particularly effective in treating yeast infections of the nails.
With most of these medications you have to monitor the patient's liver function, but that's not necessarily a reason to fear them. Tylenol, in too high of a dosage, also can cause liver damage.
Explain how Penlac works, and whom it's best suited for.
Dr. Elewski: A topical treatment, Penlac applies like a nail lacquer. You apply a fresh coat daily, then once a week remove all seven layers of polish with rubbing alcohol and trim your nails. Repeat the daily and weekly routines for as long as your doctor recommends.
Penlac is not as effective as the oral treatments—its cure rate is less than 12%. However, it's an appropriate choice when you can't or don't want to use an oral treatment, such as with children with fungus. It's also appropriate to use for people with a mild infection, in conjunction with an oral drug, or as a preventive.
Are there other, new antifungal treatments in the works?
Dr. Elewski: There are other topical lacquers we're studying here at University of Alabama, Birmingham, and Schering Plough has a topical gel it's looking at. I think treatments like these will have better cure rates than the ones currently available, but they all are at least a year or two from coming to market. Nor do I think they'll be as effective as the newer oral treatments such as Lamisil.
Some people swear by over-the-counter treatments such as Fung-Off and home remedies like diluted bleach or vinegar. Are there certain types of onychomycosis they do work on?
Dr. Gold: There are a variety of over-the-counter treatments and home remedies that have been around for years. Most dermatologists believe these agents provide little relief from nail diseases, and that prescription medicines offer the best hope for effective treatment at this time.
Dr. Abuabara: They occasionally can be effective, particularly if the infection is mild (which means less than 25% of the nail is affected) and is primarily on the central aspect of the nail. The individual has to use the medicine consistently until the infection completely grows out, which takes several months.
What are some of the conditions onychomycosis is confused with, and what are the dangers in labeling something a fungal infection without a definitive diagnosis?
Dr. Daniel: Psoriasis, dishydrotic eczema, and contact dermatitis are the conditions most commonly confused with onychomycosis. Another is a thickened nail caused by trauma to the nails from shoes that are too narrow or too short.
Although rare, some forms of skin cancer can show up as a tumor under the nail. If mislabeled as a fungal infection of the nail, time wasted treating the condition could allow the cancer to spread. The Food and Drug Administration (FDA) recently issued a mandate urging physicians to confirm their diagnosis through a lab test before prescribing an oral antifungal.
Is there any connection between fungal infections of the skin and nails?
Dr. Abuabara: Most individuals tend to have chronic infections of the skin that subsequently infect the nails. Less commonly, a blunt trauma loosens the nail plate and allows fungi entry to the nail bed. It appears from research that the most important factor in getting a fungal infection is an individual's susceptibility to the fungi coupled with the capability of her immune system to fight it off.
Are some people more susceptible to onychomycosis than others?
Dr. Daniel: Without a doubt. We think it's one of two things that makes certain people more susceptible: It's either a problem with the T-cell (a component of the blood that helps protect the body from infection) that prevents it from recognizing fungi as abnormal to the skin and nails, or there's something different about the keratin that makes up these people's nails.
How likely is someone to experience additional fungal infections of the nail, and how is that risk best minimized?
Dr. Daniel: For those who are genetically susceptible, the risk of reoccurrence is quite high because even after the original infection is cleared from their nails, the person is repeatedly exposed to fungi in her shoes, her shower, her carpet, etc.
To minimize your risks of onychomycosis returning, make sure no one else with whom you come in close contact has it. You also want to make sure you wear properly fitted shoes to minimize trauma to your toenails that could break the protective seal between the nail plate and nail bed. Always wear shoes or sandals in public places.
I also recommend to my susceptible patients that they continue to use a topical antifungal skin cream (such as Loprox) and Penlac as preventive measures.
How contagious is onychomycosis?
Dr. Gold: Fungi easily can be spread by nail technicians who use unsterile instruments, and they flourish when artificial nails are placed over an already infected natural nail.
Can artificial nails cause onychomycosis?
Dr. Scher: Yeast infections and pseudomonas bacterial infections are closely associated with artificial nails, but artificial nails don't cause fungal infections. If someone is wearing artificial nails and gets a fungal infection, there is a connection, but the artificial nail is not the direct cause.
The fungi kingdom is comprised of several fungi families, including yeasts, dermatophytes, and mpld. To understand fungal infections of the nails, also called onychomycosis, you need only be concerned with two broader classes of fungi -- yeasts and dermatophytes. These two classes of fungi differ only in the nutrients they need to survive.
Dermatophytes are a highly specialized group of fungi that break down keratin -- the protein the makes up hair and nails -- and absorb its nutrients. One dermatophyte in particular -- trichophyton rubrum -- reportedly is responsible for than 80% of onychomycosis (tinea unguium), 96% of athlete's foot infections (tinea pedis), 90% of jock itch infectios (tinea cruris), and more than 50% of ringworm infections of the body (tinea corporis).
In contrast, yeast, another specialized segment of fungi, thrive on sugar. Candida albicans, the most common yeast organism to infect humans, is found naturally no mucous membranes in the vagina, mouth, and gastrointestinal tracts. When the natural balance of yeast is upset, a yeast infection can result. Yeast infections also can develop under the proximal nail fold, under a nail plate that has separated from the nail bed, and between the nail plate and lifted artificial nail product.
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