Warts are skin growths that are usually fairly small and rough, and are caused by the human papillomavirus, or HPV.
HPV causes an excess amount of keratin that stimulates rapid growth of cells on the skin's outer layer. Warts often appear on the fingers, near the fingernails, or on the hands.
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Types of warts
- Plantar warts: This type of wart usually appears as flesh-coloured or light brown lumps that are flecked with small clotted blood vessels that appear as tiny black dots. Plantar warts (verrucas) appear on the soles of the feet.
- Genital warts: Genital warts can appear in the pubic area, on the genitals, around/in the anus, and/or in the vagina. They look like small flesh-coloured, pink or red growths in or around the sex organs. The warts may look similar to the small parts of a cauliflower or they may be very tiny and difficult to see. They often appear in clusters of three or four, and may grow and spread rapidly. They are not usually painful, although they may sometimes cause mild pain, bleeding and itching. HPV infection is the most common sexually transmitted infection (STI) in the UK and certain strains of the virus - but not those causing genital warts - can cause cervical cancer.
- Flat warts: This type of wart is more common in teens and children than in adults. Flat warts are smoother and smaller than other warts and they generally occur on the face. Flat warts also can appear on the legs, especially among females.
Warts are caused through direct contact with HPV, which is contagious. HPV may spread by person-to-person contact or through direct contact with an object used by a person with the virus. The virus that causes warts also can spread to other parts of the body of the person with warts.
How are warts treated?
In most cases, warts found on the skin are harmless and can disappear without treatment. However, genital warts should be checked by a doctor.
Sometimes, warts may recur after treatment and more than one type of treatment may be necessary. Although practitioners attempt to clear warts quickly, most methods require multiple treatments. Treatments may include:
- Freezing (cryotherapy): A doctor will use liquid nitrogen to freeze a wart. This helps to kill the cells of the wart. The dead tissue falls off within a few weeks.
- Salicylic acid: The acid ‘burns’ off the top layer of the wart. Every few days the dead tissue can be rubbed away with emery paper, so the wart is removed bit by bit.
- Covering with duct tape: One study found that covering a wart with strong adhesive tape is likely to clear the wart within a month or two (duct tape was used in the study.) In this study, about seven in 10 warts had cleared within two months using duct tape. It may be worth a try as it is painless. However, further studies are needed to clarify the role of this treatment.
- Minor surgery: When warts cannot be removed by other therapies, surgery may be used to cut away the wart. The base of the wart will be destroyed using an electric needle or by cryosurgery (deep freezing).
- Laser surgery: This procedure uses an intense beam of light (laser) to burn and destroy wart tissue. It may be used for warts that are difficult to treat.