Warts are small growths on the skin or inner linings of the body that are caused by a type of virus.
Warts are small areas of hardened skin that can grow on almost any part of the body. Human papillomaviruses (pap-ill-LO-mah VY-rus-es) (HPV) cause warts. More than 100 different kinds, or strains, of HPV exist. 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 soles 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 without causing a wart.
About one in four people have common, flat, or plantar warts at some time in their lives. Children tend to have warts more often than adults, 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 cause of 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.
Healthcare providers can diagnose a wart by its appearance. If individuals have a wart, they should see a professional who can examine the wart, determine exactly what is growing on the skin, and recommend the best treatment. In the case of genital warts, a doctor may also screen a woman for cervical cancer by performing a pelvic exam * , including a Pap smear * . In most cases, warts eventually disappear without any treatment. But, if a person has several warts or if the warts are painful or seem to be spreading, several possible treatments exist.
Over-the-counter medicines containing salicylic (sah-lih-SIH-lik) acid can remove common warts. Depending on the particular brand of medicine, the person may be able to paint it on or may be able to use a stick-on patch that attaches directly to the wart. These over-the-counter medicines can take longer than other treatments do, but they are painless. People who have diabetes * or other conditions that affect the circulatory system should first consult with a doctor before using these over-the-counter medicines.
Another typical treatment for common warts and also for plantar warts is cryotherapy, or freezing. In cryotherapy, a medical professional freezes the wart with a special chemical. Afterward, a scab develops as the skin heals. Plantar warts can be difficult to treat because most of the wart is located beneath the surface of the skin. Medical professionals may use electrosurgery to burn plantar warts—and also sometimes common warts—with a tool that uses an electric current. Sometimes, a doctor will recommend an acid-containing chemical peel to treat flat warts, which grow in such large bunches that the other types of treatments usually are not efficient. These chemicals, which are applied to the skin, eventually peel away the warts. Doctors also may use laser treatment to destroy large warts that prove difficult to remove. In some cases, doctors may use a cream called imiquimod, which is applied to the site of the wart and stimulates the body's immune system to fight the HPV.
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. If 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 allows the doctor to find and treat the disease in its early stages.
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, individuals 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 they got the virus. If people have 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. The prevention of genital warts can be difficult because skinto-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.
See also Cervical Cancer • Genital Warts • Human Papillomavirus (HPV) • Sexually Transmitted Infections (STIs): Overview • Skin and Soft Tissue Infections • Vaccines and Immunization
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American Academy of Dermatology. PO Box 4014, Schaumburg, IL 60168. Toll-free: 866-503-7546. Website: https://www.aad.org (accessed March 1, 2016).
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* genitals (JEH-nih-tuls) are the external sexual organs.
* rectum is the final portion of the large intestine, connecting the colon to the outside opening of the anus.
* vagina (vah-JY-nah) is the canal, or passageway, in a woman that leads from the uterus to the outside of the body.
* cervix (SIR-viks) is the lower, narrow end of the uterus that opens into the vagina.
* immune system (im-YOON SIStem) is the system of the body composed of specialized cells and the substances they produce that helps protect the body against disease-causing germs.
* chronic (KRAH-nik) means lasting a long time or recurring frequently.
* pelvic exam is an internal examination of a woman's reproductive organs.
* Pap smear is a common diagnostic test used to look for cancerous cells in the tissue of the cervix.
* diabetes (dye-uh-BEE-teez) is a condition in which the body's pancreas does not produce enough insulin or the body cannot use the insulin it makes effectively, resulting in increased levels of sugar in the blood. This can lead to increased urination, dehydration, weight loss, weakness, and a number of other symptoms and complications related to chemical imbalances within the body.
* HIV, or human immunodeficiency virus (HYOO-mun ih-myoono-dih-FIH-shen-see), the virus that causes AIDS (acquired immunodeficiency syndrome), is an infection that severely weakens the immune system.