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Diseases and Conditions
Special to CNN.com
Common warts are noncancerous skin growths caused by a virus called the human papillomavirus (HPV). This virus causes a rapid growth of cells on the outer layer of your skin.
There are 60 or more types of HPV. Some types tend to cause warts on your skin. Common warts usually occur on your hands, fingers or near your fingernails. Other types of HPV tend to cause warts in other places, such as on the soles of the feet, the genitals or the face and legs.
Common warts are different from moles, and they aren't cancerous. In fact, they're usually harmless and often disappear on their own. But you may find common warts bothersome or embarrassing, and you may want treatment to remove them.
Treatment helps prevent common warts from spreading to other parts of your body or to other people. But common warts may recur after treatment, and they may be a persistent problem.
Signs and symptoms
Common warts are:
- Small, fleshy, grainy bumps
- Flesh-colored, white, pink or tan
- Rough to the touch
Warts may occur singly or in multiples. They often contain one or more tiny black dots, which are sometimes called wart seeds but are actually small, clotted blood vessels. Common warts are usually painless. Young adults and children appear to be affected most often.
Other locations for warts
Other types of HPV tend to cause warts in other places:
- Plantar warts. These occur on the soles of your feet. They usually look like flesh-colored or light brown lumps with tiny black dots in them. These dots are small, clotted blood vessels.
- Genital warts. These are among the most common types of sexually transmitted diseases. They can appear on your genitals, in your pubic area or in your anal canal. In women, genital warts can also grow inside the vagina.
- Flat warts. These warts are smaller and smoother than other warts. They generally occur on your face or legs. They're more common in children and teens than in adults.
You get common warts through direct contact with the human papillomavirus (HPV). Like other infectious diseases, wart viruses pass from person to person. You can also get the wart virus by touching a towel or object used by someone who has the virus. Each person's immune system responds to warts differently, meaning not everyone who comes in contact with HPV develops warts. Some types of warts — such as genital warts — are quite contagious, but the chance of catching common warts from another person is small.
If you have warts, you can spread the virus to other places on your own body. Warts usually spread through breaks in your skin, such as a hangnail or scrape. Biting your nails can also cause warts to spread on your fingertips and around your nails.
When to seek medical advice
Most common warts don't require medical treatment, but some people choose to have their warts treated because they are bothersome, spreading or a cosmetic concern. Most warts disappear on their own or with home care. Prompt treatment by a doctor or dermatologist, however, may decrease the chance that the warts will spread to other areas of your body or to other people.
See your doctor if your warts or your child's warts persist, despite home treatment. Also see your doctor if your warts are bothersome, painful or rapidly multiplying.
Because warts shed HPV, new warts can appear as quickly as old ones go away. They can also spread to other people.
Warts don't require treatment, but you may want to treat them for cosmetic purposes and to prevent their spread. Home treatment is often effective in curing warts. Salicylic acid, an over-the-counter medication, or even duct tape and patience may be enough to resolve warts.
If you have stubborn warts and home treatment isn't helping, your doctor may suggest one of the following approaches, based on the location of your wart, the degree of your symptoms and your preferences. Doctors generally start with the least painful, least destructive methods, especially in young children.
- Freezing (cryotherapy or liquid nitrogen therapy). Your doctor may use liquid nitrogen to destroy your wart by freezing it. This treatment isn't too painful, and is often effective, although you may need repeated treatments. Freezing works by causing a blister to form around your wart. Then, the dead tissue sloughs off within a week or so.
- Cantharidin. Your doctor may use cantharidin — a substance extracted from the blister beetle — on your warts. Typically, the extract is mixed with other chemicals, painted onto the skin and covered with a bandage. The application is painless, but the resulting skin blister can be uncomfortable. However, the blister has an important purpose. It lifts the wart off your skin, so your doctor can remove the dead part of the wart.
- Minor surgery. This involves cutting away the wart tissue or destroying it by using an electric needle in a process called electrodessication and curettage. However, the injection of anesthetic given before this surgery can be painful, and the surgery may leave a scar. For these reasons, surgery is usually reserved for warts that haven't responded to other therapies.
- Laser surgery. Laser surgery can be expensive, and it may leave a scar. It's usually reserved for tough-to-treat warts.
If you have a bad case of warts that hasn't responded to standard treatments, your doctor may refer you to a dermatologist for further treatment including:
- Imiquimod (Aldara). This immunotherapy medication is marketed for the treatment of genital warts, but it's also successful in treating common warts. Immunotherapy attempts to harness your body's natural rejection system to fight off warts. This prescription cream appears to increase the skin's immune response to the wart, resulting in the death of the wart.
- Bleomycin (Blenoxane). Your doctor may inject a wart with a medication called bleomycin, which kills the virus. Bleomycin is used infrequently for warts, but in higher doses, is used to treat some kinds of cancer.
Common warts can be tough to get rid of completely or permanently, especially when they appear around and under your nails. And, if you are susceptible to the wart virus, you probably always will be. New warts may crop up even after successful treatment. More than one treatment or more than one approach to treatment may be necessary to manage the problem. Warts are viral and antibiotics are not effective for viral illnesses.
To reduce the risk that you or your child will get or spread warts:
- Don't brush, clip, comb or shave areas with warts in order to avoid spreading the virus.
- Don't use the same file or nail clipper on warts as you use on healthy nails.
- Don't bite your fingernails if you have warts near your fingernails.
- Don't pick at warts. Picking may spread the virus. Consider covering your child's warts with an adhesive bandage to discourage picking.
- Keep your hands as dry as possible, because warts are more difficult to control in a moist environment.
- Wash your hands carefully after touching your warts.
Unless you have an impaired immune system or diabetes, try a self-care approach to treating common warts:
- Salicylic acid. Wart medications and patches are available at drugstores. You can use them to treat warts at home. For common warts, look for a solution or patch containing 17 percent salicylic acid (Compound W, Occlusal-HP), which peels off the infected skin. These products require daily use, often for a few weeks. For best results, soak your wart in warm water for 15 to 20 minutes before applying a solution or patch, and file away any dead skin with a nail file or pumice stone between treatments. Just be careful. The acid in these products can irritate or damage healthy skin around the wart. If you're pregnant, talk with your doctor before using an acid solution. Stronger salicylic acid preparations are available with a prescription. Your doctor may instruct you to use salicylic acid after freezing or other therapies.
- Duct tape. A study in 2002 reported findings that showed that duct tape wiped out more warts than cryotherapy did. Study participants who used "duct tape therapy" covered their warts with duct tape for six days. After removing the tape, they soaked their warts in water and then gently rubbed the 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 the wart and surrounding skin, prompting the body's immune system to attack. In any case, duct tape is a promising, inexpensive, convenient treatment that may be especially good for children who find cryotherapy to be painful and frightening. If your warts are resilient, your doctor may even recommend using duct tape and salicylic acid.