HPV infection causes warts. More than 100 varieties of human papillomavirus (HPV) exist.
Different types of HPV infection can cause warts on different parts of your body. For example, some types of HPV infection cause plantar warts on the feet, while other varieties of HPV infection are responsible for the warts that most commonly occur on the face or neck. More than 40 different strains of HPV affect the genital area.
Most HPV infections don’t lead to cancer. But some types of genital HPV can cause cancer of the cervix — the passage between the vagina and the uterus. Vaccines can help protect against the strains of genital HPV most likely to cause genital warts or cervical cancer.
HPV infection occurs when the virus enters your body through a cut, abrasion or small tear in the outer layer of your skin. The virus is transferred primarily by skin-to-skin contact.
Genital HPV infections are contracted through sexual intercourse, anal sex and other skin-to-skin contact in the genital region. Some HPV infections that result in oral or upper respiratory lesions are contracted through oral sex.
It’s possible for a mother with an HPV infection to transmit the virus to her infant during delivery. This exposure may cause HPV infection in the baby’s genitals or upper respiratory system.
In most cases, your body’s immune system defeats an HPV infection before it has a chance to create any warts. When warts do appear, they may vary in appearance depending on which variety of HPV is involved:
- Genital warts. Genital warts may appear as flat lesions, small cauliflower-like bumps or tiny stem-like protrusions. In women, genital warts appear most commonly on the vulva but may also occur near the anus, on the cervix or in the vagina.
In men, genital warts may appear on the penis and scrotum or around the anus. Genital warts rarely cause discomfort or pain, though they may itch.
- Common warts. Common warts appear as rough, raised bumps that usually occur on the hands, fingers or elbows. In most cases, common warts are simply a nuisance because of their appearance, but they may also be painful or susceptible to injury or bleeding.
- Plantar warts. Plantar warts are hard, grainy growths that usually appear on the heels or balls of your feet, areas that feel the most pressure. These warts may cause discomfort or pain.
- Flat warts. Flat warts are flat-topped, slightly raised lesions darker than your regular skin color. They usually appear on your face, neck or on areas that have been scratched. HPV infections that cause flat warts usually affect children, adolescents and young adults.
Most cases of cervical cancer are caused by two specific varieties of genital HPV. These two HPV strains usually don’t cause warts, so women often don’t realize they’ve been infected. Early stages of cervical cancer typically cause no signs or symptoms.
That’s why it’s important for women to have regular Pap tests, which can detect precancerous changes in the cervix that may lead to cancer. The current guidelines recommend that women ages 21 to 29 have a Pap test every three years. Women ages 30 to 65 are advised to continue having a Pap test every three years, or every five years if they also get the HPV DNA test at the same time. Women over 65 can stop testing if they’ve had three normal Pap tests in a row, or two HPV DNA and Pap tests with no abnormal results.
When to see a doctor
If you or your child has warts of any kind that cause embarrassment, discomfort or pain, seek advice from your doctor.