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fungal nail infection occurs when a
fungus attacks a fingernail, a toenail, or the skin
under the nail, called the nail bed. Fungi (plural of
fungus) can attack your nails through small cuts in
the skin around your nail or through the opening between your nail and nail
If you are healthy, a fungal nail infection
probably won't cause serious problems. But it may look bad, hurt, or damage
your nail or nail bed.
A fungal nail infection could lead to more
serious problems if you have
diabetes or a weak
immune system. Talk to your doctor about the best way
to treat a nail infection if you have one of these problems.
molds, and different kinds of fungi can cause fungal nail infections. Most are
caused by the same type of fungus that causes
Fungi grow best in warm,
moist places, and 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.
A nail with a fungal
When you have a fungal nail infection, it can be
uncomfortable or even painful to wear shoes, walk, or stand for a long time.
The fungus could also spread to other nails or your skin. Over time, the
infection can cause permanent damage to your nail or nail bed.
doctor will diagnose a fungal nail infection by looking at the nail, asking
about your symptoms and past health, and possibly doing tests to look for
Whether to treat a fungal nail
infection is up to you. If it isn't treated, it won't go away. It might
If you decide to treat a fungal nail infection, you can try a nonprescription antifungal medicine that comes in a cream, lotion, or nail polish. Your doctor can also prescribe a stronger medicine. You may need to use this medicine for a
few weeks or for as long as a year. Even so, it may not get rid of the
Antifungal pills give the best chance of curing a
severe fungal nail infection. But they may cost a lot and have serious side
effects. You will need to see your doctor for regular testing if you take these
Fungal nail infections often come back after treatment. It is important
to take steps to prevent this.
Learning about fungal nail infection:
Living with a fungal nail infection:
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Fungal nail infections can be caused by
three different types of
fungus, alone or in combination.
You can get a fungal nail
infection when you come in contact with the fungus and it begins to grow on or
under your nail. Fungi grow best in warm, moist areas, such as the area around
the toes. But you can have fungi on your skin without getting a nail
infection. You have to be likely to get the infection (susceptible)
for it to develop. If you are susceptible to fungal infections, they tend to
return, even after successful treatment and especially if you don't take
It is not clear why some people are more
susceptible to fungal infections than other people.
A fungal nail infection usually isn't painful.
But without treatment, over time it can become uncomfortable or even painful to wear shoes, walk, or stand for a long time.
Your symptoms will depend
type of infection you have. The two most common infections are both caused by dermatophytes.
Distal subungual onychomycosis affects both the nail and the skin underneath the
nail (nail bed). Symptoms include:
White superficial onychomycosis is a
fungal infection of the nail surface. Symptoms include:
Not all nail infections are fungal infections. Conditions
with similar symptoms include eczema, psoriasis, and Reiter's syndrome.
Fungal infections are classified by where they begin and what they affect.
Most fungal nail infections affect the skin under the nail (nail bed) and the
nail itself (nail plate).
Fungal nail infections typically get worse, or progress, very slowly.
The rate at which a fungal infection progresses depends on:
You may first notice a fungal nail infection when a nail or
skin under the nail (nail bed) becomes discolored, damaged, thickened, or
broken. If not treated, a fungal infection is likely to get worse and spread to
other parts of the nail, the nail bed, and possibly the surrounding skin. Over
time, the whole nail may become infected and damaged and may eventually fall
Fungal nail infections can be treated successfully. But some
types are easier to treat than others. The most
common type, distal subungual onychomycosis, can be a lifelong infection and
hard to treat. Another type, white superficial onychomycosis, is easy to treat. Even after treatment, your nails may still look irregular in
shape and appearance. It can take a year or longer before they return to
Fungal nail infections often return. Of people
successfully treated with antifungal pills, 15% to 20% get another
infection in the next year.footnote 1
Bacterial infection can be a
complication of a fungal nail infection. A common bacterial infection, acute
paronychia, causes inflammation and swelling of the
skin and tissues near a fingernail or toenail.
You are more likely to get a nail infection if you:
Call your doctor for an
immediate appointment if a
fungal nail infection shows signs of bacterial
infection, such as:
Call your doctor for an appointment if your symptoms are
troubling you, such as when:
If you think you have a fungal nail infection, see your doctor. Your doctor can check your nail and recommend ways to treat it.
Watchful waiting is a wait-and-see approach. If you get better on your own, you won't need treatment. If you get worse, you and your doctor will decide what to do next.
If a nail is discolored or damaged but isn't painful, you
may decide not to treat the infection. Antifungal medicine doesn't guarantee a
cure, and antifungal pills (oral medicine) can be expensive and have
dangerous side effects. But treatment may stop the
infection from causing permanent damage to the nail and increase the chance of
Health professionals who can diagnose and treat a
fungal nail infection include:
To prepare for your appointment, see the topic Making the Most of Your Appointment.
To determine the cause of a nail
problem and diagnose a
fungal nail infection, your doctor:
Tests used to examine nail and debris samples
Almost all fungal toenail infections are caused by a type
of fungus called a dermatophyte. Because of this, if
the KOH test shows that there's a fungus present, your doctor may assume that the
infection is caused by a dermatophyte and prescribe treatment. But
because one medicine may work better than another medicine against
certain types of fungus, your doctor may want to do a fungal culture.
Your doctor may
remove a small piece of nail and look at it under a microscope (nail
biopsy) if the KOH preparation and fungal culture do not show the
presence of fungi but a fungal infection is still suspected.
Whether to treat a fungal nail
infection is up to you. For example, you may decide not to treat a fungal nail infection if your nail is discolored or damaged but not painful.
Treatment for a
fungal nail infection includes using medicines and possibly removing the
Treatment often starts with antifungal medicines. A cream, gel, or nail polish may be used. You can buy some of these medicines yourself, but you'll need a prescription for others.
Your doctor will prescribe a topical or oral
antibiotic if you get a bacterial
infection along with the fungal infection.
Some people are not sure whether they want to use antifungal pills because of the side effects.
If you have a
condition such as
diabetes that might complicate a minor foot injury or
infection, your doctor may suggest treating a fungal nail infection, even if it
doesn't bother you.
Combining nail removal with antifungal creams or pills
is likely to be more effective than using one of these treatments alone.
If you have a mild fungal
infection or are concerned about the risks of oral antifungal medicine,
consider using a topical treatment, such as Lamisil or Penlac.
Even after treatment, your nails may still look irregular in shape
and appearance. It can take a year or longer before they return to
Fungal nail infections often come back.
fungal nail infection has been successfully treated,
take steps to prevent the infection from coming back.
If you have diabetes, take special care of your feet to prevent nail infections. And if you smoke, try quitting.
If you have a mild
fungal nail infection or are concerned about the risks
of taking antifungal pills, try an
antifungal medicine you put directly on your skin
Some people find that
tea tree oil or cream works well for treating and
preventing athlete's foot and mild fungal nail infections.footnote 3 Some people have found a Vicks VapoRub to be useful for treating fungal nail infections.footnote 4
infection has cleared up, take steps to prevent it from coming back.
Antifungal medicine is standard treatment
fungal nail infection. The goals of treatment are to
have few or no side effects, provide a long-term cure, and reduce treatment
If you're thinking about using oral medicines, you may want to think about the type of infection you have, the cost of treatment, side effects, and how the pills can help or hurt you.
Surgical nail removal may be used to treat severe or recurring
fungal nail infections. After the diseased nail tissue
is removed, an antifungal cream can be applied directly to the infected area.
This is likely to work better than using one of these treatments alone.
Nail removal is rarely needed.
Nonsurgical nail removal may be used to treat severe or recurring
fungal nail infections. A urea ointment is applied to
the nail. The ointment softens and dissolves the nail so that it can be easily removed.
After the diseased nail tissue is removed, an antifungal cream can be applied
directly to the infected area. This is likely to work better than using
one of these treatments alone. Nail removal is rarely needed.
Laser treatments for fungal nail infections use a highly focused beam of light on the infected toenail. Some people may find it helpful. It may take several treatments and about 6 months for the infection to clear up. But there is no good proof yet that this treatment works.
Some people find that
tea tree oil or cream works well for treating and
athlete's foot and mild fungal nail infections.footnote 3
have found an over-the-counter menthol ointment (Vicks VapoRub) to be useful for treating fungal nail infections.footnote 4
Habif TP, et al. (2011). Tinea of the nails (Onychomycosis). In Skin Disease: Diagnosis and Treatment, 3rd ed., pp. 259–262. Edinburgh: Saunders.
Habif TP (2010). Fungal nail infections section of Nail diseases. In Clinical Dermatology: A Color Guide to Diagnosis and Therapy, 5th ed., pp. 956–961. Edinburgh: Mosby Elsevier.
Murray MT, Pizzorno JE Jr (2006). Melaleuca alternifolia (tea tree). In JE Pizzorno Jr, MT Murray, eds., Textbook of Natural Medicine, 3rd ed., vol. 1, pp. 1053–1056.
St. Louis: Churchill Livingstone Elsevier.
Derby R, et al. (2011). Novel treatment of onychomycosis using over-the-counter mentholated ointment: A clinical case series. Journal of the American Board of Family Medicine, 24(1): 69–74.
Other Works Consulted
Merritt B, Scher RK (2010). Diseases affecting the nail unit. In JC Hall, ed., Sauer's Manual of Skin Diseases, 10th ed., pp. 347–359. Philadelphia: Lippincott Williams and Wilkins.
Tosti A, Piraccini BM (2010). Tinea unguium. In MG Lebwohl et al., eds., Treatment of Skin Disease, 3rd ed., pp. 743–745. Edinburgh: Mosby Elsevier.
Wolff K, Johnson RA (2009). Fungal infections and onychomycosis section of Disorders of the nail apparatus. Fitzpatrick's Color Atlas and Synopsis of Clinical Dermatology, 6th ed., pp. 1014–1021. New York: McGraw-Hill.
ByHealthwise StaffPrimary Medical ReviewerPatrice Burgess, MD - Family MedicineSpecialist Medical ReviewerE. Gregory Thompson, MD - Internal Medicine
Current as ofFebruary 20, 2015
Current as of:
February 20, 2015
Patrice Burgess, MD - Family Medicine & E. Gregory Thompson, MD - Internal Medicine
How this information was developed to help you make better health decisions.
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