The fungus, the same organism that causes athlete's foot, thrives in damp environments such as pool areas and locker rooms, but it also lurks in hotel rooms and can even hitch a ride on your pet. "You'd be surprised at all the places you can pick it up," says Asra Ali, assistant professor of dermatology at the University of Texas Medical School at Houston. The fungus rarely infects fingernails because they are exposed to air and light. You're more likely to get it if your parents had toenail fungus, you smoke, have a weakened immune system, or have cuts and cracks in your nails or cuticles.
If you spot a white, scaly-looking mark on a toenail, see your family doctor, podiatrist, or dermatologist. A scraping can be tested to confirm the diagnosis. If the infection is mild, the most common therapy is to trim the affected part of the nail and apply a topical lacquer. Many over-the-counter varieties are on store shelves. Penlac by Dermik Laboratories (AVE
), which requires a prescription, is approved by the U.S. Food & Drug Administration. It costs around $250 for the recommended 48-week course. You paint it on like nail polish every day. Once a week, you use alcohol to remove the accumulated layers and start over. Its efficacy is improved if you file the top of your nail to improve penetration.
A more serious infection may require an oral antifungal like Lamisil, made by Novartis (NVS
), or Sporanox, from Janssen Pharmaceutica Products. They can cost more than $900 for a standard three-month course. Insurance often won't cover the cost because toenail fungus is considered a cosmetic problem even though it can be painful or dangerous if you get a secondary bacterial infection. The drugs can have serious side effects such as liver damage, so you'll need blood tests while you're on them. Home remedies that may work over a six-month period include daily applications of tea tree oil or Vicks VapoRub, or soaking your toes in a 1:2 vinegar and water solution.
The best treatment, of course, is prevention. Use an antifungal foot powder if your feet sweat a lot. Clip your toenails short and so they match the contour of your toes. Wear flip-flops in public showers and slippers in hotel rooms. Go to licensed nail salons and take your own tools. And, as your mother already told you, change your socks every day. By Kate Murphy