Toenail fungus has many remedies, but is hard to cure

Q: I have a toenail fungus that just won't go away. What can I do?

A: Fungal toenail infections occur when a fungus infects the area under the surface of a toenail. Fungi love warm, damp environments, and the space inside our shoes provides the perfect habitat.

As the infection takes hold, it creates a strong, unpleasant odor. The toenail thickens and turns yellowish-brown. Eventually the nail may separate from the nail bed.

Fungal infections are notoriously difficult to get rid of, but there are things you can do to stop their spread and improve your toenail's appearance.

First, visit a doctor to make sure your infection is, in fact, a fungal infection. A number of conditions, including age and psoriasis, can masquerade as fungal infections.

If you are dealing with a fungal infection, you'll have many treatments from which to choose:

Over-the-counter products. There are many over-the-counter antifungal preparations available in pharmacies. Unfortunately, there is no evidence that they work for toenail fungus (though they work for “athlete's foot,” another fungal infection of the skin between the toes).

Prescription topical treatments. The FDA recently approved two new prescription antifungal products: efinaconazole (Jublia) and tavaborole (Kerydin). Both are applied daily, much like nail polish. It can take up to a year to see improvement.

Oral medications. Newer medications, itraconazole (Sporanox) and terbinafine (Lamisil), are taken by mouth. They work well. But they can harm the liver, so your doctor will need to perform blood tests periodically to check your liver function. Itraconazole also interacts with many other drugs, including statins. So if your doctor prescribes this, ask if any of the medicines you might be taking could interact with it. (While doctors should check this in prescribing a new medicine, the fact is, because of the pressures of time, we sometimes don't.)

Debridement. In some cases, a doctor can scrape off the infected part of the nail.

Laser treatment. One or two laser treatments will kill the fungus. But the infection often reappears.

Surgery. Surgical removal of the nail will completely eliminate the infection. But your nail will not grow back afterward.

Home remedies. A study published in the Journal of the American Board of Family Medicine found that applying Vicks VapoRub every day for 12 weeks eliminated the fungus in five of 18 people and reduced it in 10 others. I don't know what prompted the doctors to do that study, but I'll bet they got the idea from patients who had tried it and found it successful.

Finally, whether you're trying to clear up a fungal infection or hoping to avoid getting one, the following can help:

• Wash and dry your feet thoroughly every day.

• Wear socks that wick away perspiration. (Acrylic is better than cotton.)

• Use antifungal foot powder daily.

• Avoid shoes that keep your feet from breathing.

• Wear sandals or flip-flops in shower rooms at gyms or pools.

• Dr. Anthony Komaroff is a physician and professor at Harvard Medical School. To send questions, go to AskDoctorK.com, or write: Ask Doctor K, 10 Shattuck St., Second Floor, Boston, MA 02115.