Plantar warts are small, noncancerous growths on the sole of the foot that occur due to a particular strain of human papillomavirus (HPV).
Some athletes, including dancers, gymnasts, and swimmers, may be more likely to get plantar warts due to being barefoot in communal areas. People with a weakened immune system are also at higher risk.
In this article, learn more about the causes and symptoms of plantar warts, as well as the treatment options.
A skin growth on the foot may be a plantar wart if it:
- is raised or flat
- feels hard
- has a rough surface
- has small black dots in it
A plantar wart may sometimes be painful when a person walks or presses on it.
This type of wart can either be solitary, meaning that just one appears, or mosaic. Mosaic warts are collections of warts that cluster together in the same area of skin.
When skin cells become infected with HPV, the virus tends to make them grow quicker than the cells in surrounding areas, causing a wart to form.
The HPV virus that causes plantar warts is contagious, which means that it can spread between people, particularly in warm, wet environments.
People may be more likely to get plantar warts if they:
- have a weakened immune system, which makes it harder for the body to fight off the HPV virus
- walk barefoot in a swimming pool, locker room, or communal shower area
- have skin-to-skin contact with someone who has a plantar wart
- share shoes or unwashed socks that come into contact with both people's bare feet
Plantar warts can look similar to corns and calluses on the feet, which are layers of skin that develop to protect areas of the skin from friction and pressure. A doctor can do a physical examination to see whether the growth is a plantar wart.
In some cases, the doctor may take a skin sample of the wart and send it to a laboratory for testing. This procedure is called a biopsy.
Warts often go away without treatment. About 65–78% of warts shrink or disappear within 2 years.
If they do not go away after this time, or a person wants to remove them more quickly, there are several treatment options, including:
A doctor may prescribe salicylic acid for plantar warts. This compound is usually the first treatment option for removing warts.
People can apply salicylic acid topically to the wart each day over a few months.
Cryotherapy uses liquid nitrogen to freeze off the wart. Researchers have found this method to be less effective than salicylic acid in some situations. Most dermatologists will use both treatments in combination to maximize the likelihood of removing the wart.
To get the best results from cryotherapy, people may need to return every 3 weeks for repeat treatment. Some people require several treatments with cryotherapy to resolve the wart. Cryotherapy tends to be painful and, therefore, may not be suitable for young children.
If warts do not respond to other treatments, immunotherapy can stimulate the immune system to fight off the HPV virus that is responsible for their development.
Fluorouracil (5-FU) is a chemotherapy drug that people can use off label and apply as a cream to the wart. The medical community does not recommend it for use in women who are pregnant or planning to become pregnant.
People can also take oral medication, such as cimetidine, off label in an attempt to boost the immune response, although there is a lack of evidence to recommend its use in all populations. Some researchers have suggested that oral zinc supplementation may be beneficial, but the evidence is similarly inconclusive.
Intralesional candida injection is another type of treatment that studies have proven to be quite successful as an off label treatment for warts. It essentially involves the injection of the antigen from the yeast Candida into one or two warts in the affected area.
This antigen ramps up the immune system, which helps resolve the injected wart, as well as other warts in the area. In people who respond to this treatment, multiple injections are sometimes necessary to make a noticeable difference.
Laser treatment involves the use of a beam of high intensity light to destroy the wart. This treatment can be effective, but it can sometimes cause scarring.
According to the American Osteopathic College of Dermatology, the pulsed dye laser method is 60–75% effective in removing warts that are difficult to treat. However, multiple treatments may be necessary.
Only a doctor or certified dermatologist should deliver this treatment.
People should avoid having surgical removal of the wart because residual wart can remain, and the whole wart may grow back.
People with the following conditions should check with their doctor before treating the wart themselves:
- circulatory problems
- any cardiovascular condition
- vascular disease
Home remedies for plantar warts include:
- Salicylic acid: People can apply an over-the-counter (OTC) salicylic acid medicine, such as those available for purchase here, to the plantar wart. This method can take up to 12 weeks or even longer to remove the wart.
- Pumice stone: People can first soak the foot in warm water for 10–15 minutes to soften the wart, then rub it with a pumice stone or emery board. Pumice stones are available to purchase in drug stores and online.
- Duct tape: An anecdotal but unproven method for treating plantar warts is to cover the wart with duct tape. Experts believe that this decreases the oxygen supply to the virus that is causing the wart. There is mixed evidence on whether this method is effective, but it is safe to try.
- Freezing creams: People can use OTC creams that will freeze the plantar wart off. These may include dimethyl ether and propane creams, which may be less effective than salicylic acid. As these treatments are unlikely to work well, doctors generally discourage their use. Anyone interested in this type of therapy should make an appointment with a dermatologist to have cryotherapy using liquid nitrogen instead.
People who use a pumice stone or emery board on their wart should take care not to use it on any other part of their body or share it with others, as this can spread the infection. They should also replace it every so often to avoid reinfecting their foot.
People may also find that wearing flat, comfortable shoes helps them walk without irritation or pain.
People may be able to avoid getting plantar warts by:
- wearing shoes or sandals in locker rooms, swimming pool areas, and communal showers
- keeping the feet clean and dry
- avoiding contact with warts on other people
- avoiding using a pumice stone or emery board that has been in contact with a wart
- wearing clean, dry socks when wearing shoes
- avoiding going barefoot in communal areas
Plantar warts often go away without treatment within 2 years. However, if a person wants to remove the plantar wart, they can see their doctor for prescription medicine or have a medical procedure to reduce its appearance.
People may also be able to treat the wart at home with OTC products, such as salicylic acid.
Some warts can look similar to other skin growths, so people should also see a doctor if they are unsure what the growth is or notice any unusual symptoms, such as:
- bleeding or oozing
- shape or color changes
- changes in size
People with diabetes, a weakened immune system, or a circulatory health issue that affects the feet should seek the advice of a doctor before trying any treatment that may damage the skin.