Signs and symptoms of plantar warts include:

• Small, fleshy, grainy bumps on the soles of your feet
• Hard, flat growths with a rough surface and well-defined boundaries
• Gray or brown lumps with one or more black pinpoints, which are actually small, clotted blood vessels, not "wart seeds"
• Bumps that interrupt the normal lines and ridges in the skin of your feet
• Pain or tenderness when walking

When to see a doctor
See your doctor if:

• The warts are painful or change in appearance or color.
• The warts persist, multiply or recur, despite home treatment.
• The warts interfere with your activities.
• You have diabetes or a circulatory disorder. Don't try to treat any plantar warts at home. See your doctor for advice.

In some cases, you may need to consult your doctor to ensure a correct diagnosis. It's possible for more serious lesions to crop up on your feet, including cancerous tumors called carcinomas and melanomas. If you can't confidently identify your lump, see your doctor.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

You acquire warts through direct contact with the human papillomavirus (HPV). There are more than 100 types of HPV. Some types of HPV tend to cause warts on your hands, fingers or near your fingernails. Others tend to cause warts on your feet.

The virus that causes plantar warts isn't highly contagious, but it thrives in warm, moist environments, such as shower floors, locker rooms and public swimming areas. So you may contract the virus by walking barefoot in public places.

Like other infectious diseases, HPV may also pass from person to person. If you have a plantar wart, you can even spread the virus to other places on your own foot by touching or scratching. The virus can also spread by contact with skin shed from a wart or blood from a wart.

Each person's immune system responds to warts differently, so not everyone who comes in contact with HPV develops warts. Even people in the same family react to the virus differently. That's why parents and kids don't necessarily spread warts by sharing the same shower.

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Plantar warts are more likely to appear on the feet of people with:

• Damaged or cut skin
• Weakened immune systems

For reasons doctors don't understand, some people are more susceptible to the wart-causing virus, just as some people are more likely to catch a cold. Children and teenagers tend to be especially vulnerable to warts.

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Plantar warts can be persistent. They can shed the virus into the skin of your foot before they're treated, prompting new warts to grow as fast as the old ones disappear. The best defense is to treat new warts as quickly as possible so that they have little time to spread.

If untreated, warts can enlarge and spread, developing into clusters of warts called mosaic warts. They may also become extremely painful. If you have lots of plantar warts, the pain may make it difficult for you to walk or run.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

You're likely start by seeing your family doctor or primary care doctor. However, in some cases when you call to set up an appointment, you may be referred immediately to a specialist in skin diseases (dermatologist).

Because appointments can be brief and there's often a lot of ground to cover, it can help to be well prepared. Here are some tips to help you get ready for your appointment and what to expect from your doctor.

What you can do

• Write down any symptoms you're experiencing, and for how long you've experienced them.
• Make a list of all recent exposures to possible sources of infection. These may include trips to a local swimming pool or using a communal shower or locker room.
• Make a list of your key medical information, including other conditions you're being treated for and the names of any medications, vitamins or supplements that you're taking.
• Write down questions to ask your doctor. Don't be afraid to ask questions or to speak up when you don't understand something your doctor says.

For plantar warts, questions you may want to ask include:

• Are there any other possible causes for my symptoms?
• What are my treatment options and the pros and cons for each?
• If the first treatment doesn't work, what will we try next?
• How soon after I begin treatment can I expect improvement?
• Am I contagious? How can I reduce the risk of passing this infection to others?
• Can I wait to see if the condition goes away on its own?
• What skin-care routines do you recommend while the condition heals?
• What kind of follow-up, if any, should I expect?

What to expect from your doctor
Your doctor is likely to ask you a number of questions, such as:

• When did you first notice the warts?
• Are the warts painful?
• What at-home treatments have you used and how long have you used them?
• Have you noticed any changes in the appearance of the wart?

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In most cases, your doctor can diagnose plantar warts just by inspecting your feet. If there's any doubt, your doctor may need to pare down the lump with a scalpel. Plantar warts will show signs of pinpoint bleeding from their dark dots, which are really blood vessels.

If there's still doubt about the diagnosis, your doctor may remove a small section of the wart (shave biopsy) and send it to a laboratory for analysis.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Plantar warts don't require treatment, but you may want to treat them if they're painful or to prevent their spread. Home treatment is often effective in curing plantar warts. Salicylic acid, an over-the-counter medication, or even duct tape and patience may be enough to resolve plantar warts.

If you have stubborn plantar warts and home treatment isn't helping, your doctor may suggest one of the following approaches. Doctors generally start with the least painful, least destructive methods, especially in young children.

• Freezing (cryotherapy, or liquid nitrogen therapy). Your doctor can apply liquid nitrogen with a spray canister or cotton-tipped applicator to freeze and destroy your wart. This treatment isn't too painful and is often effective, although you may need repeated treatments. The chemical causes a blister to form around your wart, and the dead tissue sloughs off within a week or so. Freezing therapy may be painful so isn't typically done on young children.
• Cantharidin. Your doctor may use cantharidin — a substance extracted from the blister beetle — on your plantar warts. Typically, the extract is paired with salicylic acid, applied to the plantar wart and covered with a bandage. The application is painless, but the resulting skin blister can be uncomfortable. Your doctor clips away the dead part of the wart in about a week.
• Minor surgery. This involves cutting away the wart or destroying the wart by using an electric needle in a process called electrodesiccation and curettage. This treatment is effective, but may leave a scar if not done carefully. Your doctor will anesthetize your skin before this procedure.
• Laser surgery. Doctors can use several types of lasers to eliminate stubborn warts. Laser surgery is expensive and painful and may require multiple sessions to treat the warts.
• Immunotherapy. This therapy attempts to harness your body's natural rejection system to remove tough-to-treat warts. This can be accomplished in a couple of ways. Your doctor may inject your warts with interferon, a medication that boosts your immune system's instinct to reject warts. Or your doctor may inject your warts with a foreign substance (antigen) that stimulates your immune system. Doctors often use mump antigens, because many people are immunized against mumps. As a result, the antigen sets off an immune reaction that may fight off warts.
• Imiquimod (Aldara). This prescription cream is an immunotherapy medication that encourages your body to release immune system proteins (cytokines) to help ward off warts. You can apply this cream directly to your warts. Imiquimod is approved by the Food and Drug Administration for the treatment of genital and perianal warts, but it's also successful in treating common warts and plantar warts.
• Bleomycin (Blenoxane). In severe cases that haven't cleared with other therapies, your doctor may inject each wart with a medication called bleomycin, which kills the virus. This medication is given systemically in higher doses to treat some kinds of cancer. The injections for wart treatment can be painful. They're not used if you're pregnant or breast-feeding or if you have circulation problems.

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The following self-care approach can help you treat plantar warts. Do not treat plantar warts at home if you have an impaired immune system or diabetes.

• Salicylic acid. Nonprescription wart medications and patches are available at drugstores. To treat plantar warts, you'll need a 40 percent salicylic acid solution or patch (Curad Mediplast, Dr. Scholl's Clear Away Plantar, others), which peels off the infected skin a little bit at a time. Apply the solution once or twice each day, being careful to avoid healthy skin, which can become irritated from the acid. In between applications, pare away the dead skin and wart tissue using a pumice stone or emery board. You may need to repeat this process for several weeks to completely eliminate warts.
• Freezing (cryotherapy) products. Products that freeze plantar warts, such as Compound W Freeze Off or Dr. Scholl's Freeze Away Wart Remover, are available at drugstores without a prescription. Such products aren't as effective as cryotherapy done at the doctor's office, however, because they don't freeze tissue at as low of a temperature as liquid nitrogen therapy.
• Duct tape. In a well-publicized 2002 study, duct tape wiped out more warts than freezing (cryotherapy) did. Study participants who used "duct tape therapy" covered their warts in duct tape for six days, then soaked their warts in water, and gently rubbed warts with an emery board or pumice stone. They repeated this process for up to two months or until their warts went away. Researchers hypothesize that this unconventional therapy may work by irritating warts and the surrounding skin, prompting the body's immune system to attack. Today, duct tape is commonly used to treat warts, especially for children who may find freezing painful or scary. It's often combined with salicylic acid.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

To reduce your risk of plantar warts:

• Avoid direct contact with warts. This includes your own warts.
• Keep your feet clean and dry. Change your shoes and socks daily.
• Don't go barefoot in public areas. Wear shoes or sandals in public pools and locker rooms.
• Don't pick at warts. Picking may spread the virus.
• Don't use the same file, pumice stone or nail clipper on your warts as you use on your healthy skin and nails.
• Wash your hands carefully after touching your warts.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.