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Fact Sheet: Warts are lumpy growths in the skin caused by infection with human papilloma viruses
Warts are lumpy growths in the skin caused by infection with human papilloma viruses (HPV), of which there are more than 100 known types. Most wart infections are harmless and disappear within two years, often without needing treatment.
Human papilloma viruses are common worldwide. Animal papilloma viruses cannot infect people. Different types of papilloma virus infect different areas of the body (see also genital warts).
The wart virus is thought to be transmitted by direct skin to skin contact or by contact with contaminated surfaces, for example floors.
Warts develop on the skin of children and adolescents and mainly occur on the knuckles, the backs of the hands and the knees. Occasionally such warts appear as a group.
Are flat-topped and are most common on the face and the back of the hands.
Occur on the soles of the feet and occasionally on the palms of the hands. They are found most commonly in older children and adolescents.
Diagnosis is usually made by examination of the growth, but occasionally a doctor may request a scraping or biopsy.
(time between becoming infected and developing symptoms)
2 to 3 months, but ranging from 1 to 20 months.
(time during which an infected person can infect others)
Unknown, but at least as long as visible warts persist.
About 65% of warts will go away by themselves within 2 years. If treatment is necessary, the following may be used:
Exclusion from childcare, preschool, school or work is not necessary.
Wart infection can be prevented by the following measures: