Encyclopedia / W / Warts


What Are Warts?

Warts are common, benign skin growths caused by a viral infection. They usually appearing on the hands, elbows, face, and soles of the feet, but may also be located on the genitals. Nongenital warts are harmless and only mildly contagious.

There are a number of different types of warts, named for their location on the body and their appearance: common warts (verrucae vulgaris) are most often seen on the hands and fingers; plantar warts are located on the soles of the feet; periungual warts are located around the nails of fingers and toes; digitate warts are small fingerlike projections that appear on the scalp or face; filiform warts are thin, threadlike projections commonly found around the face and neck; flat warts may occasionally occur in groups of up to several hundred at a time.

Ordinary nongenital warts are only mildly contagious; they spread most commonly from one location to another—for example, from finger to finger—on an infected person, rather than from person to person. (Genital warts, on the other hand, are highly contagious and may contribute to the development of penile and cervical cancers.)

Many warts disappear spontaneously within one or two years, or removal may be attempted with a variety of treatments. Because the virus may be present in neighboring tissues, recurrence is common. As people grow older, however, most develop an immunity to warts.

Who Gets Warts?

Warts are common, affecting 7% to 10% of the population. They are seen on people of all ages, but most commonly appear in children and young adults. The majority of people seeking treatment for warts each year are under 40 years of age.


  • A benign small growth on the skin, typically on the hands.
  • Warts may be pale or dark, rough or smooth, raised or flat; appearance depends on the location of the wart and the human papillomavirus type. Common warts appear as rough growths.
  • Clusters of multiple warts.
  • Thin hornlike projections.
  • Bleeding or itching (in some cases).
  • Warts can be painful depending on the size and location.

Causes/Risk Factors

  • Warts are caused by the human papillomavirus (HPV), of which there are more than 60 types. The virus enters the skin through tiny breaks and can be transmitted by direct physical contact with another person. Several strains of HPV associated with genital warts have been implicated as causing cervical cancer.
  • People with weakened immune systems—such as those infected with HIV or undergoing treatment with immunosuppressant medications—have a higher risk for developing widespread, persistent warts.
  • Contrary to popular belief, you cannot get warts from handling frogs or toads.

What If You Do Nothing?

Nongenital warts are harmless, and up to 80% of them disappear by themselves in one or two years (typically two years, at least in children). Genital warts, on the other hand, must be treated. And because plantar warts can make walking uncomfortable, they, too, may need medical attention.

Be aware that warts that have gone away on their own and also return just as mysteriously.


  • Diagnosis can be made by observation of the characteristic appearance and does not usually require a doctor.


  • In healthy people most warts (including genital warts) will heal without treatment in six months to three years, when the body develops an immune response.
  • Wart removal preparations containing salicylic or lactic acid are available over the counter. Do not use these wart removal preparations to remove facial or genital warts; such preparations are too harsh for sensitive facial and genital skin.
  • Warts may be removed by freezing them off (cryosurgery), by laser surgery, or by electrocautery (burning warts off with an electric current). These treatments can be painful, may leave scars, and are not first-line therapies for young children.
  • Imiquimod cream (Aldara) is approved as a prescription for enhancing the immune response to warts, thus helping the body fight the human papilloma virus.
  • Topical retinoids tretinoin (Retin-A) or tazaratene, which are vitamin A derivatives, may be prescribed to treat flat warts.
  • Your doctor may apply caustic chemical solutions such as cantharidin or trichloroacetic acid to destroy the warts.
  • Squaric acid may be used to elicit an immune response in a treatment plan called immunotherapy.


  • You can use an electric razor or depilatory in lieu of a conventional razor to prevent nicks that may promote the spread of warts on the face or legs.
  • Do not scratch existing warts.

When To Call Your Doctor

  • Make an appointment with a doctor or dermatologist if you want warts removed; anticipate more than one visit as warts are often resistant to treatment.
  • See a doctor if you are over age 45 and develop warts or are unsure of the diagnosis of warts.
  • New or unusual skin growths should be evaluated to rule out skin cancer.
  • See a doctor if you or your sexual partner develops genital warts.

**Reviewed by Kevin Berman, M.D., Ph.D., Atlanta Center for Dermatologic Disease, Atlanta, GA. Review provided by VeriMed Healthcare Network. **