Acclaim Dermatology

Nail fungus

Overview: Nail fungus

It’s easy to get a fungal nail infection. If you have a fungal infection on your foot, the fungus can spread to one or more of your nails. This is quite common.

You can also catch a fungal nail infection in a warm, moist place like a pool deck or locker room. If someone else has a fungal infection and walked barefoot there, all you have to do is walk barefoot in the same area.

Having wet nails for a long time can also lead to nail fungus. Some people develop it when they wear the same pair of sweaty shoes or boots every day. Fingernails that are wet for hours at a time due to a job or hobby are also susceptible.

What you see on infected nails will vary with the type of fungus causing the infection.

Most people see some nail discoloration. The nail may have a white spot. Some nails turn yellow, brown, or green. As the infection worsens, infected nails can thicken, lift up from the finger or toe, or crumble. Some nails become thinner.

Treatment is important. It can prevent the infection from causing more damage to your nails.

If you have diabetes or a weakened immune system, treatment is especially important. After getting a fungal nail infection, people who have diabetes have an increased risk of developing sores that do not heal. Sores that do not heal can lead to a serious health problem. It’s important to see a dermatologist (or other doctor) at the first sign of a nail problem. A dermatologist can tell you whether you have a nail infection or something else.

Early diagnosis and treatment are recommended for everyone who has nail fungus. Caught early and treated, a fungal nail infection is likely to clear and you’ll regrow a healthy nail.

Treatment can also prevent the fungus from spreading to other parts of your body and to other people.

You cannot get rid of a nail infection by covering it with nail polish or artificial nails.

Nail fungus: Signs and symptoms

If you get nail fungus, you’re likely to see one or more of the following changes to your nails:

  • Part of a nail turns white, yellow, brown, or another color. At first, you may just see a spot of discoloration at the tip of your nail. Without treatment, this discoloration may spread, covering more of the nail.
  • Debris builds up under the nail
  • A nail begins to lift up, so it’s no longer firmly attached to the finger or toe.
  • A nail turns white, and the surface of the nail may feel soft, dry, and powdery. The nail also thins, so you may be able to scrape off the nail.
  • Nails thicken and turn yellow or brown, often this affects all of the fingernails.
  • A nail splits or crumbles

Having nail fungus is usually painless. At least, it’s painless in the beginning. If you put off getting treatment, however, the fungus can grow. When the fungus worsens on toenails, wearing shoes can become painful.

If you see any changes to a nail, you should see a dermatologist. When caught early, nail fungus may clear with treatment applied to the nail. As the fungus grows, it becomes more difficult to clear the infection.

Who gets nail fungus?

Nail fungus is common, and anyone can get it. Some people, however, have a higher risk of developing a fungal nail infection. Your age, health, and even your lifestyle can increase your risk.

Age: The risk of developing a fungal nail infection increases with age. It’s most common in old age and least common in children.

Before the age of 6, it’s rare to develop a fungal nail infection.

Climate: Living in a hot, humid climate increases the risk of developing a fungal nail infection.

If you get frequent nail infections, you may have untreated athlete’s foot.

Health: You have an increased risk of developing a fungal nail infection if you have one or more of the following:

  • Athlete’s foot (or another skin infection caused by fungus)
  • Cancer and are receiving chemotherapy
  • Diabetes
  • Had a nail infection
  • Injured a nail or recently had nail surgery
  • People in your family frequently get nail infections
  • Poor circulation
  • Psoriasis
  • Received an organ transplant
  • Weakened immune system due to a disease like human immunodeficiency syndrome (HIV)

Lifestyle: Your risk of getting a fungal nail infection increases if you:

  • Have wet feet or hands frequently throughout the day
  • Smoke
  • Spend a lot of time in water
  • Walk barefoot in a hot, humid place like a pool, public shower, or locker room
  • Wear tight-fitting, closed-toe shoes, especially if you have sweaty feet
  • Wear plastic gloves for hours every day

What causes nail fungus?

Tiny, microscopic organisms called fungi (the plural of fungus) cause a fungal nail infection.

Many people pick up the fungi when they have skin-to-skin contact with someone who has a fungal infection like athlete’s foot or ringworm on their hands.

Another common way to get a fungal nail infection is by walking barefoot in a warm, moist area like a pool deck or locker room. These fungi thrive in warm, moist areas.

You can also get a fungal nail infection by sharing an infected nail clipper or towel.  

But you don’t have to catch it from someone. You can get it if your nails are frequently moist or you often wear sweaty socks and shoes.

The fungi usually infect a nail by getting into a:

  • Small cut in the skin surrounding your nail
  • Crack in your nail
  • Separation between the nail and finger (or toe)

The area under a nail gives fungi a warm, moist place to grow. The infection can then spread to other nails and even your skin.

Nail fungus: Diagnosis, treatment, and outcome

How do dermatologists diagnose nail fungus?

To find out if a patient has nail fungus, a dermatologist examines your nails and nearby skin. It’s important to check the skin because the fungus can spread. You may already have a skin infection caused by fungus like athlete’s foot.

To get rid of the infection, you will need to treat all infected areas.

Before giving you the diagnosis, your dermatologist may also take some samples. Collecting a bit of debris from beneath a nail, trimming off part your nail, or scraping off a bit of skin can be very helpful. In a lab, these samples can be examined under a microscope to find out what’s causing the problem.

How do dermatologists treat a fungal nail infection?

Treatment usually begins with your dermatologist trimming your infected nail(s) — cutting back each infected nail to the place where it attaches to your finger or toe. Your dermatologist may also scrape away debris under the nail. This helps get rid of some fungus.To completely get rid of the infection, most people also need one or more of the following treatments:

Medicine you apply to the nail: If you have a mild infection, a medicine that you apply to your nails may get rid of the infection. This treatment helps keep new fungus out while the nails grow. Fingernails typically grow out in 4 to 6 months. Toenails take longer, usually takes 12 to 18 months.

Probably the most difficult part of this treatment is remembering to use it as often as prescribed. Some treatments must be applied every day. Others you apply once a week. To get the best results, it’s essential that you apply these medicines exactly as directed.

The U.S. Food and Drug Administration (FDA) has approved the following medicines that you apply to the nail to treat nail fungus:

  • Amorolfine (ae-moe-roll-fean)
  • Ciclopirox (sic-low-pie-rocks)
  • Efinaconazole (eh-fine-ah-con-ah-zole)
  • Tavaborole (ta-va-bore-ul)

Side effects from these medicines are generally mild. Possible side effects include redness and swelling, an ingrown toenail, and stinging or burning when you apply the medicine. In clinical trials, none of these side effects caused patients to stop using the treatment.

Medicine you take: If you need more-aggressive treatment, your dermatologist may prescribe antifungal pills. These have a higher cure rate than medicine you apply to your nails.

Antifungal pills also work more quickly than medicine applied to the nails. Taking antifungal pills for 2 months can cure an infection under the fingernails. Usually 3 months of treatment cures a toenail fungal infection.

Antifungal pills, however, can cause side effects. Your dermatologist will watch you closely. You’ll also need to have blood tests every month to check for problems.

The FDA has approved the following systemic (works throughout the body) medicines to treat nail fungus:

  • Fluconazole (flu-con-ah-zole)
  • Griseofulvin (griz-e-oh-full-vin).
  • Itraconazole (it-rah-con-ah-zole)
  • Terbinafine (ter-bin-ah-fine)

Combination therapy: Sometimes, nail fungus is hard to clear. Studies show that taking antifungal pills and applying medicine to your nails can be more effective than using either treatment alone.

Nail removal: If you have a severe infection or other treatments just don’t work, your dermatologist may recommend removing the nail(s) to get rid of the infection. Your dermatologist will use one of the following techniques to remove the nail:

  • Nonsurgical nail removal (a chemical is applied to the nail)
  • Surgical nail removal

Your dermatologist can perform both types of nail removal in a medical office or a clinic.

With either procedure, the nail can grow back. If the infection fails to clear, however, your dermatologist can treat the nail so that it cannot grow back.

Researchers continue to look for safe, effective treatments: While there are many treatment options, none is ideal. Medicine applied to the nails has a low cure rate. Antifungal pills can cause side effects. Nail removal requires wound care.

To improve treatment, researchers are looking for new and better ways to treat nail fungus. One treatment showing promise is the use of lasers and light treatments to clear nail fungus. While promising, more research is needed to know whether this treatment can provide safe and effective treatment for most people.

Researchers are also looking at other potential treatments, including patches, nail lacquers, and gels.

What is the outcome for someone who has nail fungus?

With treatment, many people can get rid of nail fungus. Even when the fungus clears, your nail(s) may look unhealthy until the infected nail grows out. A fingernail grows out in 4 to 6 months and a toenail in 12 to 18 months.

To clear the fungus, it’s important to:

  • Use the treatment exactly as prescribed
  • Apply (or take) the medicine for as long as prescribed
  • Keep all follow-up appointments with your dermatologist

Nail fungus can be stubborn. If you had a severe infection, it’s possible to clear the infection. A healthy looking nail, however, may be unrealistic, but you can expect the nail to look better and feel more comfortable.

Even with clearing, nail fungus can return. You’ll find steps to reduce your risk in Tips: 12 ways to prevent another nail infection.

Nail fungus: Tips

12 ways to prevent another nail infection

Fungal infections are contagious, so you can get another one. Taking the following precautions can reduce your risk.

1.    Wear flip flops or shower sandals when walking in warm, moist areas like gyms, locker rooms, spas, public showers, and pools. This can prevent you from catching nail fungus and athlete’s foot.

2.    If you just finished treating nail fungus, throw away shoes, boots, skates, and other footwear that you wore before you started treatment. Fungus can live in footwear, giving you another infection.

If your footwear is expensive or new, you can disinfect them using an ultraviolet (UV) shoe sanitizer or ozone cabinet. You can buy these online.

3.    Put on a clear pair of socks every day and whenever your socks get sweaty. This helps prevent fungi from growing. Wearing moisture-wicking socks can also reduce the need to change your socks.

4.    Wear shoes that:

  • Fit well (not tight)
  • Are made of leather, canvas, or mesh
  • Keep your feet dry and prevent overheating

This helps prevent fungi from growing in your shoes.

5.    Alternate shoes. Fungi thrive in moist places like damp shoes. You can reduce this growth by giving shoes 24 hours to dry out before wearing them again.

6.    Sprinkle antifungal powder in your shoes. These products cannot treat a fungal nail infection, but they can help prevent fungus from growing in your shoes.

7.    Keep your nails short. When trimming your toenails, you want to cut them straight across and keep your toenails shorter than the end of your toes. Fingernails should also be kept short. This helps prevent fungi and other germs from getting under your nails.

8.    Sanitize your nail clipper before using it. To sanitize your nail clipper, wash it with soap and water and then wipe it with rubbing alcohol.

If you go to a salon for nail care, ask how often they disinfect nail clippers, emery boards, and other equipment. They should sanitize these after every client. If not, the equipment can spread a fungal infection from one client to another.

9.    Never share nail clippers, shoes, skates, towels, and other personal items. You can easily pick up a fungal infection by sharing a personal item. People also get athlete’s foot and ringworm (a fungal infection on the skin) by sharing personal items.

10.    Keep your feet clean and dry. Carefully wash your feet with soap and water every day, taking care to wash between your toes. Dry your feet well after washing them.

You also want to avoid having damp or sweaty feet for too long. A damp, warm area provides the perfect area for fungi to thrive.

11.    Moisturize dry skin. Fungi can get in through small cracks in your skin. To ease dry skin, moisturize within 5 minutes of bathing and after washing your hands.

12.    If you get athlete’s foot, treat it right away. Fungi also cause athlete’s foot. This fungal infection can spread to your nails.

Check your nails to find early signs of infection

Following these precautions will reduce your risk of getting another infection. Fungal infection, however, are very common. You can get another one. Early treatment delivers the best outcome.

You can find signs of an early fungal infection by checking your nails and the skin around them at least once a month. You want to look for:

  • Changes in nail color, such as a white spot or brown or yellow streak
  • Changes to the texture of your nails
  • Soreness or swelling around a nail
  • Dry, itchy skin

If you notice any signs of infection, make an appointment to see your dermatologist.


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Bhatta AK, Keyal U, et al. “Fractional carbon-dioxide (CO2) laser-assisted topical therapy for the treatment of onychomycosis.” J Am Acad Dermatol. 2016;74:916-23.

Gold LFS and Rosen T. “Onychomycosis: Diagnosis, treatment, and prevention strategies.” Dermatology News (A CME/CE certified supplement). March 2016:2-15.

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Verma S and Heffernan MP. “Onychomycosis.” In: Wolff K, Goldsmith LA, et al. Fitzpatrick’s Dermatology in General Medicine (seventh edition). McGraw Hill Medical, New York, 2008: 1817-20.

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Gold LFS and Rosen T. “Onychomycosis: Diagnosis, treatment, and prevention strategies.” Dermatology News (A CME/CE certified supplement). March 2016:2-15.

Verma S and Heffernan MP. “Onychomycosis.” In: Wolff K, Goldsmith LA, et al. Fitzpatrick’s Dermatology in General Medicine (seventh edition). McGraw Hill Medical, New York, 2008: 1817-20.

Gold LFS and Rosen T. “Onychomycosis: Diagnosis, treatment, and prevention strategies.” Dermatology News (A CME/CE certified supplement). March 2016:2-15.

Gold LFS and Rosen T. “Onychomycosis: Diagnosis, treatment, and prevention strategies.” Dermatology News (A CME/CE certified supplement). March 2016:2-15.

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