Common Warts Overview

Extreme closeup of wart.
You'll want to avoid one of these eyesores at all costs. See more pictures of skin problems.
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You can relax: That old story about getting warts from kissing a frog might just be one of the oldest examples of an urban legend. Your kissing habits have nothing to do with wart formation. You can't get warts from handling a toad, either. Let's take a look at what common warts are, where they come from and why they're so hard to get rid of.

A common wart is a noncancerous growth. Common warts are typically found on the hand -- on the back of the hand, around fingernails and on the fingers. They can also be found on elbows and knees. These warts are hard, round bumps with surfaces that feel rough to the touch. Their size is usually between 0.08 and 0.39 inches (between 2 and 10 millimeters) [source: Merck]. They might be the same color as your skin, or they might be white, grayish-brown, pink or tan. You might see black dots when you look at a common wart. These seedlike black dots lend another name to common warts: seed warts [source: American Academy of Dermatology].


Common warts aren't dangerous. They'll go away if they're left untreated, but this can take anywhere from months to years. Moreover, warts left untreated on children are likelier to clear up than ones on adults [source: WebMD]. Some people want to get rid of their common warts because they don't want to look at them. Others want them gone because they're a nuisance -- perhaps the wart causes pain when a person swings a golf club or holds a pencil. Sometimes, common warts begin to multiply, and in that case, treatment is especially desirable.

Read on to find out why some people get warts easily and others never do.


Causes of Common Warts

Common warts, like other types of warts, are caused by the human papillomavirus (HPV). There are more than 100 different types of HPV, and a large number of them can cause skin warts.

A wart begins forming when HPV infects the top layer of skin. A break in the skin (such as a scrape or cut) makes it easier for the virus to enter the body. The infection causes skin cells to multiply rapidly. Despite this rapid growth of skin cells, the wart forms so gradually that it could take anywhere from several weeks to nine months before you can actually see the wart on the surface of your skin.


It's possible that immunity to warts increases with age. Young children are more susceptible to common warts than adults are, and girls are more likely to develop warts than boys. Experts say that about 10 percent of children will get common warts, and those who do get them are typically between the ages of 12 and 16 [source: Bacelieri]. Children who bite their fingernails or chew hangnails are more susceptible to acquiring warts. The skin abrasions caused by biting and chewing the fingers and nails create perfect entry points for the HPV virus.

You can take some precautions to avoid getting warts, but it's impossible to ensure you won't get them. Read on to learn about how common warts spread.


Spreading of Common Warts

Common warts spread easily -- kind of like the common cold. Why some people get them and others don't is a mystery. However, it's clear that if you have a weakened immune system, you are more susceptible to warts. An HPV infection triggers the creation of antibodies that fight the virus, and someone with a weakened immune system may not be as successful at creating these antibodies.

There are a variety of ways for common warts to spread. No matter the method of transmission, they're more likely to infect you if you've got breaks in your skin. One possible route to infection is through person-to-person physical contact. However, touching someone else's wart doesn't automatically guarantee that you'll get warts yourself -- the chances of this happening are actually fairly slim [source: Mayo Clinic].


Person-to-object transmission is a more common way for warts to spread. If you come into contact with items that someone who's infected with HPV has touched, you're at risk for developing common warts. Use caution when handling shared towels, bath mats and razors, as HPV can thrive in these damp objects.

You can get warts from other people or things, but you can also give them to yourself. If you already have common warts, you can spread them to other places on your own body, especially where there are breaks in the skin. Biting your nails or picking at hangnails might cause warts to break out around your nails or on your fingertips.

Unfortunately, there's no way to completely avoid exposure to HPV, and once you have it, you're at risk for developing common warts. Reduce your chances of getting common warts by making sure you know what precautions you can take, which you can learn about on the next page.


Preventing Common Warts

Once you have them, common warts can be notoriously difficult to get rid of. Therefore, it's important to reduce your chances of developing warts in the first place.

One easy way to reduce your chances of developing common warts is by cleaning cuts or scratches on your skin. Even a tiny break in your skin makes you more susceptible to warts.


Just as the athlete's foot fungus loves dampness, so do some types of HPV. Wearing flip-flops when you walk on wet surfaces, such as in a locker room or at a swimming pool, is an easy way to decrease your exposure to plantar and common warts.

Even though there's no guarantee that you'll get a wart by touching someone else's wart, it's wise to wash your hands with soap and water if contact occurs. In fact, regular hand-washing is a good precaution whether or not you've come into contact with someone who has warts. For one thing, someone who doesn't have any visible warts might still harbor the virus and pass it along to you.

You also need to protect yourself from, well, yourself. As we've learned, if you've got common warts, there's a risk that you'll spread warts from one part of your body to another. To prevent this from happening, you should never pick at, rub or scratch a wart. Don't bite your fingernails or chew hangnails. You should also designate a nail clipper and file to use on fingers that are infected with warts. Of course, even if you don't have warts, biting fingernails and picking at hangnails is still a bad idea -- these habits can lead to breaks in the skin, which leaves you susceptible to acquiring HPV.

Despite your best efforts to avoid warts, you still might find them cropping up. Common warts can go away on their own, but read on to find out options for speeding up the healing process.


Treating Common Warts

If you've ever had warts, there's a good likelihood that you've struggled to get rid of them. There is no foolproof method for removing them, and it's hard to know what method will work in a particular situation. Fortunately, you have a number of options.

Most people start a treatment regimen with over-the-counter products. A patch or solution with 17 percent salicylic acid works to gradually peel away infected skin. It usually takes weeks of daily use for these products to get rid of a wart. Increase your chances of success by first soaking your wart in warm water. You can also use a nail file or pumice stone to file away dead skin (but don't use the file or stone anywhere else!). Use caution with over-the-counter treatments because they can irritate the healthy skin surrounding common warts [source: Mayo Clinic]. Some people swear by the duct tape cure. If you're going this route, ensure that the duct tape covers the wart at all times. Once a week, remove the tape, soak the wart in warm water, and then rub it with an emery board or pumice stone before applying a new piece of duct tape.


If you aren't successful treating your common warts at home, it might be time to seek professional help. Your doctor may prescribe salicylic acid in a solution much stronger than the over-the-counter formula. If that fails, cryotherapy or liquid nitrogen treatment (freezing the warts) is the next option. These treatments are usually successful at removing the warts after three or four sessions. However, some people find them uncomfortable. Your doctor may opt to paint your skin with a blister-forming compound called Cantharidin and then cover it with a bandage. The resulting blister will lift the wart off the skin, but the blister can be painful [source: Mayo Clinic].

For stubborn warts, your doctor might try an alternative to the usual common wart treatments. Electrosurgery, or burning off warts with an electric needle, is one option. Warts can be removed with lasers, too, but this kind of procedure is expensive and may leave a scar. Bleomycin, an antibiotic used to treat cancer, can be injected into tough-to-cure warts. The medication kills the virus after a series of injections [source: Bacelieri]. Another treatment for very tough cases is an immunotherapy gel or cream called Imiquimod. When Imiquimod is applied to a wart, it uses the body's natural rejection mechanisms to fight off the virus. Retinoids, or vitamin A creams, are another last-resort solution for persistent warts. A retinoid can be prescribed as a cream or given orally.

For more information about getting, preventing and treating warts, refer to the resources on the next page.


Lots More Information

Related HowStuffWorks Articles


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  • American Academy of Family Physicians. "Warts: Removal by Freezing." 12/06. (Accessed 8/4/09)
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