When a wart is found on the bottom of the foot, it is known as a plantar wart. These warts are caused by the human papillomavirus (HPV). There are hundreds of types of HPV, but the most common type is verruca vulgaris, which causes what is called the common wart. Depending on the type you have, warts can appear on your hands, fingers, or feet. Warts on your feet are caused by an infection of the outer skin layer (epidermis) caused by HPV. Plantar warts are noncancerous and are mildly contagious, meaning they can spread from person to person or from one area to another on the same person. They are usually found on the soles of your feet, under pressure points, such as on the balls of your feet or on your heels. Warts seldom need urgent medical attention, but they can become painful and annoying. Some plantar warts tend to be stubborn, and they do not respond well to treatment. If this is the case, a podiatrist will remove them for you. Plantar warts can occur at any age, but are most commonly seen in children and young adults under the age of 30.
There are two types of plantar warts: solitary and mosaic. Solitary warts are single warts that may increase in size, eventually multiplying and forming satellite warts. Mosaic warts are clusters of small warts that grow close to one another. Mosaic warts are more difficult to treat than solitary warts.
Plantar Wart Symptoms
There are a few different symptoms of a plantar wart. They include:
- Possible pain when walking or standing
- Thick skin in the area where the wart is developing, resembling a callus
- Appearing very small at first, but growing larger
- Tiny black dots appear on the surface of the wart
- Clusters of warts form around a “mother wart”
If you see the tiny black dots, do not panic. They are simply dried blood that is trapped in the capillaries (tiny blood vessels). Warts tend to have rough surfaces and clearly defined borders. They are typically the same color as your skin, but they sometimes appear darker. Although some people feel pain from plantar warts, in most cases they are painless and do not itch.
What Causes Plantar Warts?
Plantar warts are caused by direct contact with the human papillomavirus, or HPV. The virus enters your system through tiny cuts or breaks in your skin. HPV is usually found in warm, moist places such as locker rooms, public showers, or swimming areas. Walking barefoot in any public place is another way to make direct contact with the virus. Like other infectious diseases, plantar warts can be spread from person to person or from one spot to another on the same person. If the wart itches and you scratch it and then shake someone’s hand or even flush a toilet, you are potentially passing the virus on to another person.
Diagnosing Plantar Warts
Diagnosing plantar warts is not always as simple as examining the foot. Most plantar warts can be distinguished by their tiny black dots and thick, scaly skin. But if your doctor wants to examine the warts further, he or she will debride (cut away) the overlying skin to look for certain characteristics seen with warts. Additionally, he or she may take a biopsy of the wart and send it to a laboratory for testing. Your doctor will also look for other physical signs that are characteristic of warts.
Plantar Wart Treatment
Because the skin surrounding the wart is thick, most over-the-counter medications do not work effectively, as they cannot adequately penetrate the skin. Most people do not necessarily need treatment for the warts themselves, but seek treatment to prevent the spread of the virus or to minimize the pain. Warts that are left untreated may take several years to disappear. At-home treatment methods may include salicylic acid to burn the wart, over-the-counter medication, or duct tape. If these methods do not work, your doctor may suggest one of the following treatment options:
Cryotherapy: This is the art of freezing the wart off with liquid nitrogen. This method is usually effective and not painful. The liquid nitrogen will cause a blister around the wart until the dead tissue falls off within a week or so.
Laser Surgery: Your podiatrist may use a laser to burn the wart off. Generally, only large mosaic plantar warts are removed with a laser beam. Laser removal increases the risk of infection, so this method may not be used unless the circumstances call for it.
Minor Surgery: This is the most popular way to remove warts—the podiatrist performs simple surgery to remove them. The healing process is mildly uncomfortable, but normal activities can resume within weeks.
Topical Acids: There are advantages to using topical acids, which do not prevent the person from continuing their normal activities. Nor is the healing process painful. Unfortunately, this method takes much longer to treat moderate to severe cases, so other methods may be suggested.
Plantar warts should not prevent you from participating in your normal activities. During treatment, however, you should try avoid spreading the virus to others by avoiding swimming in public pools or walking barefoot in locker rooms. There is no single specific wart treatment that works for everybody, which is another reason why it is so important to speak with a doctor about the problem. Some warts go away on their own, while others need to be removed surgically. Most non-prescription drugs for the treatment of warts take several weeks to work, while prescription medication may get rid of the problem in half the time. Treating warts takes patience and dedication, especially if you have to apply a cream or ointment. If you buy an over-the-counter product, be sure to follow all instructions.
When to See Your Doctor
Call your doctor immediately if:
- Self-treatment of warts has been unsuccessful
- After treatment, skin becomes hot, red, and painful
- The warts appear on the genitals or face
- Warts do not disappear after treatment
- New warts appear after treatment, possibly on the other foot or on other parts of the body
- You are over the age of 45, especially if you have never had a wart before
- Your warts are painful and bleed
Self treatment for warts is very common. There are many products available in your local drug and grocery stores, including plantar pads made by Compound W, ointments made by Boiron, and Freeze Away wart removers made by Dr. Scholl’s and Wartner. Prices for these products range from a couple of dollars to a few hundred dollars. If you are unsure about which product would work best, you may be better off seeking medical attention and advice from a podiatrist. Furthermore, if you are not certain that the lesion is a wart, you should have it checked by a podiatrist before attempting any self-treatment. Self-treatment should not be attempted if you have any medical problems, particularly diabetes, poor circulation, or neuropathy. Self-treatment of warts can lead to infection — or even amputation — in persons with these medical conditions.
Preventing Plantar Warts
Unfortunately, there is no true way to prevent warts. However, there are several things you can do to reduce your chances of contracting the virus. Preventive measures should include:
- Wearing flip-flops or sandals in wet or damp public areas (showers, pools, gyms, locker rooms)
- Avoiding sharing towels and shoe gear with others, even family and friends
- Not scratching an itchy wart
- Taking care of small cuts or openings on your skin by washing the area, applying antibiotic medication such as Neosporin, and using a Band-Aid or bandage.
- Watching for any signs of recurrence after treatment
Complications of Plantar Warts
Unlike other types of warts that may appear on your hands or fingers, plantar warts typically show up on the sole of the foot, out of view of others. Still, many people feel embarrassment about their plantar warts. Common complications include:
- Spreading to other parts of the body
- Recurrence after treatment
- Scars may be left if warts are surgically removed
- Constant itchy feeling on bottom of foot
- Need to limit activities you enjoy such as swimming
Questions to Ask Your Podiatrist
Here are some questions you may want to ask your doctor about plantar warts:
- What materials should my flip-flops or sandals be made of?
- What should I do if I see or feel a wart developing?
- Once warts develop, how long should I wait to see you?
- What are the best over-the-counter products to control my warts?
- What should I do if my plantar warts spread to other parts of my body?
- What other treatment methods would I benefit from?
- What home remedies would work best for me?