Human papillomavirus (HPV) is a group of more than 100 related viruses that can cause warts on the hands, feet, genitals, and other parts of the body.
Katy was embarrassed. The warts on her fingers had gotten worse, and she hated the thought of anyone seeing them. At dinner that night, her mother asked her what was wrong with her hands.
“Nothing,” Katy said. But at her mother's frown, she raised her right hand above the table. “They're gross,” she said, bursting into tears.
“They're warts,” her mother said. “That's no big deal. You've got a virus, that's all.”
“You mean, a virus like one that gives you a cold?”
“Exactly. Although we'll need to take you to the dermatologist to take care of them,” her mother said.
Katy sighed with relief. The warts weren't permanent, after all.
Human papillomavirus (HPV) is the name of a group of more than 100 related viruses * that can cause warts on the hands, feet, genitals * , and other parts of the body. Everyone comes in contact with HPV throughout daily life, for example, when touching doorknobs, sharing keyboards, and shaking hands. Certain forms of HPV are more likely to cause warts on the hands. Other forms are sexually transmitted and are more likely to cause genital warts. Some strains of HPV can cause both kinds of warts.
A wart is an irregular but harmless growth of skin triggered by HPV. There are several different kinds of warts. Common warts, like Katy's, usually appear on the hands. Plantar warts grow on the soles of the feet. Periungual warts grow near the nails and can affect nail growth. Filiform warts appear on the face, as can flat warts, which also appear on the arms and legs. Common warts and periungual warts are rough; flat warts are flat, and plantar warts look like calluses. Filiform warts have thin, threadlike growths sticking out.
Genital warts may take one of several shapes or may not be visible at all. Genital HPV is the most common sexually transmitted disease *
HPV thrives in warm, moist places, such as locker rooms, swimming pool areas, and showers. HPV is very contagious and can easily be spread from place to place on a person's body or between people. For example, sharing a razor can allow the virus to spread from one person to another. Or a person can spread the virus from one spot to another on his own body by scratching at a wart, picking up viruses, and then scratching another spot, which introduces the virus. Viruses enter the skin through a scratch, cut, or abrasion; swimmers often pick up the virus that causes plantar warts through a scrape caused by the concrete surfaces used around swimming pools. However, it may take two to nine months before the new wart grows.
Some people get HPV through genital contact, usually vaginal * or anal * sex. Because most people who have HPV do not realize they are infected, they can unknowingly pass the virus to their sex partners. According to the Centers for Disease Control and Prevention, about 79 million Americans have HPV and about 14 million people get the virus each year.
There are several methods of treating warts. One of them is to freeze the wart with liquid nitrogen (cryotherapy). Warts can also be removed surgically, with lasers, electricity, or cutting tools. Some people have success treating warts with home remedies, such as putting tape over the wart. Over-the-counter remedies containing salicylic acid are also useful.
No treatment is 100 percent effective. Most warts will go away on their own, although it may take years.
No treatment is available that can eliminate genital HPV. However, the body's natural defenses eliminate the infection; 70 percent of HPV infections are gone within a year, and after two years, 90 percent are eliminated. Nonetheless, some individuals with genital warts ask their doctor to remove them.
Warts may be treated with the application of medication. Salicylic acid, sold under several brand names, works by softening the layers of skin that make up the wart. Once softened, the layers can be rubbed off. Because salicylic acid is both safe and effective (although it make take months to work), it is generally considered the most desirable first treatment for warts.
Cimetidine is a medication that may be taken by mouth or as an injection. Most medications are either injected or applied topically.
If a wart does not respond to treatment with medication, the doctor may suggest surgery. Some patients opt for cryosurgery to remove their warts. For two weeks before the procedure, the patient applies a gel of salicylic acid. At the end of the two weeks, the wart will have turned white and taken on a cottony texture.
The doctor will then apply a small amount of liquid nitrogen, using a cotton swap, a spray, or a cryoprobe. The extreme cold destroys the root of the wart. Common warts are usually treated with an open spray applied for 10 seconds. The procedure may be repeated at four-week intervals.
The advantages of cryosurgery for removal of warts include a short (two-week) preparation time, minimal wound care, and a low risk of infection.
Warts may be removed with surgery. Usually, surgery involves both burning the wart with an electric current (called electrosurgery) and curettage, cutting the wart off with a scalpel. Because this treatment tends to leave scars, it is considered less desirable than cryosurgery.
Plantar warts are found on the soles of the feet. The pressure of standing and walking can cause a layer of thickened skin to form over the wart itself. Unlike other kinds of warts, plantar warts can be painful.
To treat a plantar wart, the doctor scrapes the upper layer with a knife, in a procedure called paring. Because the upper layers of a plantar wart are dead and have no blood vessels, there is little to no pain or bleeding. Paring may be used to distinguish a plantar wart from a callus; the doctor will look for evidence of blood vessels deep inside the structure, which indicate it is a plantar wart. Paring can also be used to remove skin layers and make the wart more accessible to other treatments, such as medication or cryosurgery.
Some people have reported success in removing warts by applying duct tape. They cover the wart with tape and leave it on for six days. Then they remove the tape, soak the wart, and use an emery board on the wart. They repeat the process until the wart is gone. Doctors think that this may work because the tape removes some wart tissue (called debriding) every time it is removed.
No matter how they are treated, warts often recur. Treatments kill the wart itself but not the HPV that causes them. However, given time, the body's immune system can eliminate the viruses that cause warts.
To reduce the risk of warts recurring, individuals need to avoid walking barefoot in locker rooms, swimming pool areas, and showers. They should not touch existing warts, whether their own or someone else's. They should not share personal items, such as razors or towels, with a person who has warts.
See also Genital Warts • Sexually Transmitted Infections (STIs): Overview • Warts
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Langwith, Jacqueline, ed. HPV (Perspectives on Diseases and Disorders). San Diego, CA: Greenhaven, 2013.
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American Academy of Dermatology. PO Box 4014, Schaumburg, IL 60168-4014. Toll-free: 866-503-SKIN. Website: https://www.aad.org (accessed June 13, 2016).
Mayo Clinic. 200 First St. SW, Rochester, MN 55905. Telephone: 507-284-2511. Website: http://www.mayoclinic.com (accessed July 17, 2015).
* viruses (VY-rus-sez) are tiny infectious agents that can cause infectious diseases. Viruses can reproduce only within the cells they infect.
* genital (JEH-nih-tul) refers to the external sexual organs.
* sexually transmitted disease is an infection, such as the human immunodeficiency virus (HIV) or herpes, that can be passed from person to person by sexual contact.
* vaginal (VA-jih-nul) refers to the canal in a woman that leads from the uterus to the outside of the body.
* anal refers to the anus, the opening at the end of the digestive system through which waste leaves the body.