Fungus of the Toenail

Fungal nail infections can be caused by yeasts, molds and other kinds of fungi. Fungi grow best in warm, moist places. They can spread from person to person. You can get a fungal nail infection from walking barefoot in public showers or pools or by sharing personal items, such as towels and nail clippers. If you have athlete’s foot, the fungus can spread from your skin to your nails.

You can have fungi on your skin without getting a nail infection. If you are susceptible to fungal infections, they tend to return. They can come back even after successful treatment and especially if you don’t do something to prevent them.

Symptoms often develop slowly over time. A nail with a fungal infection may:

• Turn yellow, white or brown
• Get thicker
• Crumble, split or separate from the skin

A fungal nail infection usually isn’t painful. But over time, you may be uncomfortable or even have pain when you wear shoes, walk or stand for a long time. The fungus could also spread to other nails or your skin.

To diagnose a fungal nail infection, your doctor will: 

• Look at the skin and nails on your hands and feet
• Ask about your medical history, including any previous symptoms of nail damage or fungal nail infections

The doctor may take a sample of skin and nail fragments from under the infected nail or a sample of the nail itself. Tests to examine the samples include:

• Potassium hydroxide (KOH) preparation, to find out if the problem is caused by a fungus
• Lab tests, like a fungal culture, to find out what type of fungus you have
• A nail biopsy, if the tests don’t show fungi, but your doctor still thinks you have a fungal infection

It may take time to treat a fungal nail infection. You may need to try several treatments to find one that helps. Even when a treatment works, the nail can get infected again. If you have a severe nail infection or the infection keeps coming back, your doctor may remove the infected nail.

Treatment often starts with antifungal medicine. You can try an over-the-counter medicine that comes in a cream, lotion or nail polish. If needed, your doctor can also prescribe a stronger antifungal medicine that you apply to your nail. Antifungal pills give the best chance of curing a severe nail infection, but they typically cost more and can have serious side effects. You will need to see your doctor for regular testing if you take these pills.

If you have diabetes or a weak immune system, your doctor may suggest treating the infection, even if it doesn’t bother you.

In addition to your doctor’s recommended treatment, change socks often. To avoid spreading it to others, don’t go barefoot in public places, and try not to share personal items like towels and nail clippers. Keep your nails clean and dry to stop the infection from coming back.

There are things you can do to prevent a new or repeat fungal nail infection:

• Before bed, wash and dry your feet completely. Applying a topical antifungal medicine may help prevent repeat infections.
• Keep your feet and hands dry. Dry skin and nails are less likely to get infected. Put powder on your dry feet or hands after you take a shower or bath.
• Wear sandals or roomy shoes made of materials that allow moisture to escape. Let your shoes air out for at least 24 hours between each time you wear them.
• Wear socks. Change them if your feet get damp or sweaty.
• Wear shower sandals in wet public areas, such as locker rooms or showers. Let shower sandals dry between uses.
• Do not share nail files, clippers, socks, towels or other personal items.
• Try to avoid injuring your nail. Cutting nails too short is a common cause of nail injury.