What Is It?
Human papilloma virus (HPV) causes common warts, the small, white, beige or brown skin growths that can appear almost anywhere on the body and on the moist mucous membranes near the mouth, anus and genitals.
There are more than 70 different types of HPV, each with its own favorite skin surface to invade. Some cause the small, painless, rough-surfaced warts found on the fingers and face. Others cause the larger, more painful and flatter plantar warts that grow on the soles of the feet. More than 25 different types of HPV can infect the skin covering the sex organs and opening of the anus, causing genital warts.
Certain types of genital HPV infection or warts can increase a woman's risk of developing cervical cancer. At least five different viruses that cause genital warts have been linked to the development of cervical cancer and, less often, squamous cell cancer of the penis, vagina, anus and vulva, the external genital area in women. Certain types of HPV have been linked to mouth and throat cancers.
Human papilloma viruses usually are spread by direct skin contact, such as shaking the hand of someone who has a wart on their finger or having unprotected sexual intercourse with someone who has genital warts. Less often, the viruses are carried on surfaces touched by someone who has warts, especially inside shoes that have been worn by someone with plantar warts. Once a person has been infected with an HPV, symptoms usually take three to four months to develop. However, in some cases, warts have developed as long as two years after contact with an infected person or contaminated surface.
Health experts estimate that common warts can be found on the hands of about one-fourth of all people in the United States, especially children. For some unknown reason, plantar warts are most common among teenagers and young adults.
It is possible to have an HPV skin or genital infection without having symptoms. When an HPV infection does cause a wart, the appearance varies slightly depending on its location:
Common skin warts - These most often affect the hands, face, skin or scalp, and are especially common on sites of previous skin injury. They are small (about 6 millimeters or one-fourth of an inch), firm, painless, rounded growths that are whitish, pink, beige or brown. The wart surface may be smooth and pearly or rough like a cauliflower.
Flat warts - These are flat, white, beige or brown growths that sometimes itch. They typically occur on the face, neck, chest, forearms, wrists or hands.
Plantar warts - These are thick, painful overgrowths of skin on the soles of the feet. They are often mistaken for simple calluses.
Genital warts - These usually appear as one to 10 pink, painless growths with a rough, cauliflower-like surface. In men, genital warts most commonly affect the tip of the penis, the opening of the urethra and the skin around the anus (especially in men who practice anal sex). In women, genital warts usually appear first at the posterior opening of the vagina and on the labia (the liplike folds of skin around the vagina).