Warts

Warts are small, hard growths on the skin or inner linings of the body that are caused by a type of virus.

What Are Warts?

Warts are small areas of hardened skin that can grow on almost any part of the body. They are caused by human papilloma (pah-pih-LO-mah) viruses, or HPV. There are more than 100 different kinds, or strains, of HPV. Warts are usually skin-colored and bumpy or rough, but sometimes they are dark and smooth. The way a wart looks depends on where it is growing, and different kinds of warts appear on different parts of the body.

Common warts usually grow on fingers and hands, especially around fingernails. These warts usually have a rough, bumpy surface with tiny black dots, which are the blood vessels that feed the wart and allow it to grow. Flat warts are much smaller than common warts and are very smooth. This type of wart typically grows in little bunches on the face and legs; as many as 100 flat warts may grow together in one place. Common warts and flat warts generally are not painful except under certain circumstances, such as when the pressure of a pencil pushes against a wart on the finger while writing. Plantar warts, which grow on the bottoms of the feet, can be quite painful as a person walks on them, flattening them and pushing them back into the skin. Like a common wart, a plantar wart is covered with black dots marking the place of blood vessels.

Genital warts are small and pink, and they can grow one at a time or in bunches that make them look a bit like cauliflower. This type of wart can grow on the genitals ^* , the skin around the genitals, the rectum ^* , the buttocks, or in the vagina ^* or cervix ^* . Although most warts do not cause major health problems, genital warts may itch or bleed, and the ones caused by some strains of HPV are known to increase a woman's chances of developing cancer of the cervix.

Who Has Warts and Why?

About 1 in 4 people have common, flat, or plantar warts at some time in their lives. Children tend to have warts more often than adults do, and people who bite their fingernails or pick at hangnails may be more

likely to have warts because tiny openings in the skin provide a way for HPV to enter the body. Someone with a weakened immune system, due to a chronic ^* illness or an infection, for example, also may be more likely to have warts. Warts are very contagious because HPV can pass easily from one person to another by contact. Genital warts spread through sexual intercourse. In fact, they are the most common viral sexually transmitted disease in the United States. In rare cases, a mother with genital warts can pass HPV to her baby during birth. The virus can cause growths on the baby's vocal cords or elsewhere in the infant's respiratory tract.

How Are Warts Diagnosed and Treated?

Health care providers can diagnose a wart by its appearance. It is important to have a professional examine the wart, because it is not always easy to know exactly what is growing on the skin or how to treat it. In the case of genital warts, a doctor also may screen a woman for cervical cancer by performing a pelvic exam ^* , including a Pap smear ^* . In some cases, warts eventually disappear on their own without any treatment. However, if a person has a lot of warts or if the warts are painful or seem to be spreading, there are several possible treatments.

Over-the-counter medicines containing salicylic (sah-lih-SIH-lik) acid often are used to remove common warts. The medicine can be painted on, or it may come in a patch that sticks to the wart. This type of treatment can take longer than others do, but it is painless. Cryotherapy, or freezing, is a typical treatment for common warts. A special chemical freezes the wart, and a scab develops as the skin heals. Cryotherapy may be used on plantar warts as well. These warts can be difficult to treat, because most of the wart is located beneath the surface of the skin. Electrosurgery can burn warts with a tool that uses an electric current; this type of treatment is used on both common and plantar warts. Chemical peels that contain acids are used to treat flat warts, which grow in such large bunches that the other types of treatments usually cannot be used efficiently. The chemicals are applied to the skin, and they eventually "peel" away the warts. Doctors also may use laser treatment to destroy any type of wart that proves difficult to remove. In some cases, doctors may give injections of interferon (in-ter-FEER-on), a substance that stimulates the body's immune system to attack the HPV causing the wart.

Genital warts require treatment from a doctor. To remove them, doctors may use cryotherapy, lasers, medicines that can be applied directly to the warts, or surgery. Once a woman has had genital warts, doctors may advise her to have Pap smears more often. In some cases, certain types of HPV infection can lead to cancer of the cervix, and a Pap smear will allow the doctor to find and treat the disease in its early stages.

Can Warts Be Prevented?

It can be very difficult for people to protect themselves from common, flat, and plantar warts, because they are so common and the virus spreads so easily. In addition, a person can come into contact with HPV many months or even a year before a wart grows big enough to see, so it is often impossible to know for sure where and how someone caught the virus. If a person has a wart, it is best for other people not to touch it. It is also advisable to avoid sharing towels and washcloths with someone who has a wart and to wear sandals at public showers or pools or in locker rooms, to avoid infection. It can be difficult to prevent genital warts, because skin-to-skin contact spreads them. Condoms may limit the spread of genital warts, but because some warts grow on the skin around the genitals and on the buttocks, a condom may not cover every one of them, making it still possible for the HPV to pass between sexual partners. Abstaining from sex with a person who has genital warts is the safest choice.