What is it?
- Common warts are 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.
- 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.
- Common warts usually grow on your hands or fingers. 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.
Common warts are:
- Small, fleshy, grainy bumps
- Flesh-colored, white, pink or tan
- Rough to the touch
Common warts usually occur on your hands. They may occur singly or in multiples. Warts may bleed if picked or cut and often contain one or more tiny black dots, which are sometimes called wart "seeds" but are actually small, clotted blood vessels.
Other locations for warts
Other types of HPV tend to cause warts in other places:
- Plantar warts. These occur on the plantar surfaces, or 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. A sexually transmitted infection, genital warts 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 smaller warts generally occur on your face or legs. They're usually smoother than other types of warts.
Warts are caused by a virus known as the human papillomavirus (HPV). There are 100 or more types of HPV. Some types of HPV cause relatively harmless conditions, such as common warts, while others may cause serious disease, such as cancer of the cervix. And, different types of HPV cause different types of warts.
How warts spread
Like other infectious diseases, wart viruses pass from person to person. You can also get the wart virus indirectly by touching a towel or object used by someone who has the virus. It can take a wart as long as two to six months to develop after exposure to the virus.
Each person's immune system responds to the HPV virus differently, meaning not everyone who comes in contact with HPV develops warts. 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 also can cause warts to spread on your fingertips and around your nails.
Some people are more likely to develop warts after exposure to the HPV virus, including:
Children and young adultsPeople with compromised immune systems, such as those with HIV/AIDS or people who've had organ transplants
Because warts shed HPV, new warts can appear as quickly as old ones go away. They can also spread to other people.
Your doctor can usually diagnose a wart just by looking at it. Sometimes, your doctor may scrape off the top layer of the wart to look for the clotted blood vessels that are common with warts. If the diagnosis is still in doubt, your doctor may take a small sample of the growth to be analyzed in order to rule out other causes of your skin growth.
Treatments and drugs
Many common warts don't require treatment. They usually disappear within two years, though new ones may develop nearby. You may want to treat them for cosmetic purposes, if they're causing discomfort or to prevent their spread. Home treatment is often effective in curing common warts. Salicylic acid, an over-the-counter medication, or even duct tape and patience may be enough to resolve common 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 is usually only mildly painful and is often effective, although you may need repeated treatments. Freezing works by causing a blister to form under and around your wart. Then, the dead tissue sloughs off within a week or so. Local anesthesia may be necessary for large warts, and risks of freezing include permanent damage to your nail bed and nerves in the treated area.
- 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 and may cause swelling. 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.
Other treatments and medications
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:
- Immunotherapy. This type of treatment attempts to harness your body's natural rejection system to fight off warts. Topical immunotherapy medications that may be prescribed for stubborn warts include squaric acid dibutylester and a gel called imiquimod (Aldara). Imiquimod is marketed for the treatment of genital warts but has also proved effective for treating common warts. However, warts may return when these therapies are stopped.
- Bleomycin (Blenoxane). Your doctor may inject a wart with a medication called bleomycin, which kills the virus. Bleomycin is used with caution for warts, but in higher doses, is used to treat some kinds of cancer. Risks of this therapy include nail loss and damage to the skin and nerves.
- Retinoids. Derived from vitamin A, these medications disrupt your wart's skin cell growth. Your doctor may prescribe a retinoid cream or an oral medication. These medications make your skin extra sensitive to the sun, so be sure to protect your skin from the sun while taking them.
Common warts can be tough to get rid of completely or permanently, especially when they appear around and under your nails. And, if you're 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.
Lifestyle and home remedies
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), 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 10 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. Stronger salicylic acid preparations are available with a prescription. Your doctor may instruct you to use salicylic acid after freezing or other therapies. Irritation is a common side effect of this treatment, and usually means that the treatment is working. If you're pregnant, talk with your doctor before using an acid solution.
- Duct tape. An initial study found that duct tape wiped out more warts than cryotherapy did. The "duct tape therapy" used in this study included covering warts with duct tape for six days, then soaking the warts in warm water and rubbing them with an emery board or pumice stone. The process was repeated for as long as two months. Although researchers hypothesized that this unconventional therapy worked by irritating the wart and triggering the body's immune system to attack, more recent research has disputed these findings and found that duct tape wasn't effective for treating warts. Still, the low cost and convenience of this treatment may make it worth trying, especially in children who find cryotherapy to be painful and frightening.
Although you may run across alternative treatments that promise to cure your warts, only two treatments have shown promise in small clinical trials: an oil-based garlic solution and topical vitamin D-3 patches. Though the treatments were effective, each therapy was only studied in a single trial, so the evidence isn't yet conclusive.
To reduce the risk that you or your child will get or spread warts:
- Don't brush, clip, comb or shave areas that have warts, in order to avoid spreading the virus.
- Don't use the same file or nail clipper on your warts as you use on your 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 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.
- Use footwear in public showers or locker rooms.