(Also Called 'Flat Warts')
What are warts?
Warts are an infection of the skin caused by the human papillomavirus (HPV). The virus enters the body through a break in the skin, such as a cut. It then forms a rough bump on the surface of the skin. Warts are benign (non-cancerous) growths.
Anyone can get warts, but they are more common among children because of their frequent scrapes and cuts. People with a weakened immune system, such as the elderly and people taking medicines that suppress the immune system, are also more likely to get warts.
Warts are very contagious. They are easily spread from one person to another through direct contact with a wart, or with something – such as a locker room floor or a towel – that has been in contact with a wart. They can spread to different parts of the body by nail biting or shaving. There are different types of warts. Common warts frequently occur on the hands. Warts that occur on the sole of the foot (plantar surface) are called plantar warts. They are most common on the parts of the sole that receive pressure when standing or walking.
Because of this pressure, plantar warts are often flat or grow inward. Plantar warts can appear alone or in a cluster (mosaic warts). They tend to grow slowly and can eventually sink deep enough into the skin to cause discomfort or pain. Flat warts are smaller and smoother than other types of warts and can occur anywhere.
What are the symptoms of warts?
Plantar warts are the most common type to cause symptoms because of their location. People who get plantar warts may feel as if they have a stone in their shoe. Because of their flat appearance and location on the bottom of the foot, plantar warts are frequently mistaken for calluses. Like calluses, plantar warts have tough, thick skin. However, unlike calluses, a plantar wart is painful when squeezed. A plantar wart may also have black dots on its surface. These dots are from the dilated (enlarged) blood vessels in the wart.
How are warts diagnosed?
The doctor will diagnose a wart by examining the skin and the wart and noting any symptoms you may have.
How are warts treated?
Warts may go away on their own after a certain amount of time as the immune system fights off the virus that causes them. However, since warts can be embarrassing, and can become irritated or painful (especially when located on the foot), you may want to have them treated.
In order to successfully treat a wart and reduce the chances of it coming back, it must be removed completely. This requires daily home treatment, either alone or in combination with treatments by a doctor.
Home wart treatment
Over-the-counter treatments: Salicylic acid is an over-the-counter product used to treat warts. It comes in a gel or liquid, or as a patch. Formulations with a higher percentage of salicylic acid are more effective. These treatments work better if the thick skin of the wart is pared down before application.
To treat a wart, soak the affected area in warm water for 15-20 minutes to soften the skin. After soaking, use a disposable emery board to file down the wart, break off the used section, and throw it away. After filing, apply the wart treatment and cover with duct tape. Repeat this treatment every night until the wart is gone. Salicylic acid treatment does not cause pain.
Duration of treatment: To treat a wart successfully, you have to apply the topical (on the skin) medicines every day, often for months.
It is important that you not try to physically remove the wart yourself. Doing so can lead to infection or injury to the area.
There are several approaches the doctor may choose from to treat a wart. Treatment is done on an outpatient basis, meaning the patient goes home the day of the treatment.
Medical treatment options include:
Cryotherapy: This treatment destroys the wart by freezing it with liquid nitrogen. Cryotherapy causes a blister to form; when the blister peels off, all or part of the wart peels off. This treatment is usually not used in very young children because it can be painful. Cryotherapy may require several sessions in order to be effective, and works better if you follow it with a salicylic acid treatment after the area heals.
Topical treatment: Topical medicines work by stripping away layers of the wart. However, when the doctor chooses a topical treatment, he or she will prescribe a more powerful concentration of medication, such as salicylic acid or a combination of medications, for you to apply at home.
Other: Other options to treat plantar warts include laser therapy, surgery, and immunotherapy, an approach in which the doctor uses the patient's immune system to destroy a plantar wart that is not responding to other treatments. However, because these treatments are expensive, can be painful and cause scarring and other side effects, they are used less often.
Can warts be prevented?
There is no foolproof way to prevent warts. However, there are steps you can take to reduce your risk of getting them. HPV thrives in warm and humid areas. In order to reduce the risk of getting warts:
Wear flip flops or sandals when you use a public locker room, public pool area, or public showers.
Do not touch or come in contact with another person's wart.
Do not scratch or pick at a wart.
Do not shave over a wart.
Keep items such as clothing and towels that may come into contact with the wart away from others in the house.
Can warts come back after being treated?
There is no definitive way to keep any type of wart from occurring again. A wart may reappear near the location of the one that was treated, may show up on another part of the skin, or may never occur again.
A note about HPV
HPV is also the cause of cancer of the cervix (part of the uterus or womb), and can cause cancer of the penis and anus. HPV is now the major cause of mouth and throat cancer. Most genital warts and cancers caused by HPV can be prevented by the use of condoms and by the HPV vaccines (Gardasil® and Cervarix®).
American Academy of Dermatology.
American Osteopathic College of Dermatology.
Bolognia, J., Jorizzo, J. L., & Schaffer, J. V. (2012). Dermatology. Philadelphia: Elsevier Saunders.
Centers for Disease Control and Prevention.
What is HPV?
Centers for Disease Control and Prevention.
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 4/14/2016…#15045