Warts are skin growths that are caused by the human papillomavirus (HPV). There are more than 60 kinds of HPV, some of which tend to cause warts on the skin. HPV stimulates quick growth of cells on the skin's outer layer. In most cases, common warts appear on the fingers, near the fingernails, or on the hands. Certain types of HPV can also cause warts to appear in the genital area.
Types of Warts
- Plantar warts: This type of wart usually appears as flesh-colored or light brown lumps that are flecked with small clotted blood vessels that appear as tiny black dots. Plantar warts appear on the soles of the feet.
- Genital warts: Genital warts can appear in the pubic area, on the genitals, in or around the anus, and/or in the vagina. They look like small flesh-colored, pink, or red growths. 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 usually are not painful, although they may cause mild pain, bleeding, and itching. HPV infection is the most common sexually transmitted disease in North America and certain forms of the virus can cause cervical cancer.
- Flat warts: This type of wart is more common in teens and children than in adults. Flat warts are smoother, flatter, 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 places on 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 evaluated 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): can be done with over-the-counter freezing spray products or by your doctor, who will use liquid nitrogen to freeze a wart. For the at home treatment, temperatures can reach as low as a negative 100 degrees. The down side of this home treatment is that it may not freeze the wart deep enough to be effective. It can also be painful because the spray needs to be applied longer than if you were being treated in a doctor’s office. When it works, a blister forms around the wart and the dead tissue falls off within one to two weeks.
- Cantharidin: This substance, an extract of a blister beetle and applied to the skin, forms a blister around the wart. After cantharidin is applied, the area is covered with a bandage. The blister lifts the wart off the skin.
- Other medications: These include bleomycin, which is injected into a wart to kill a virus, and imiquimod (Aldara and Zyclara), an immunotherapy drug that stimulates your own immune system to fight off the wart virus. It comes in the form of a prescription cream. Although imiquimod is stated for genital warts, it is modestly effective on other types of warts.
- Salicylic acid: Over-the-counter wart treatments come in several forms (gel, ointments or pads) and contain salicylic acid as the active ingredient. When applied on a regular basis, the acid gradually dissolves the wart tissue. The process may take several weeks.
- 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 utilizes an intense beam of light (laser) to burn and destroy wart tissue.
- Over-the-counter medication: Usually this contains salicylic acid and is applied in gel, ointment or lotion form. Applied regularly, the wart eventually peels off. This is not for use in genital warts.
Can Warts Be Prevented?
If you already have warts, you can prevent them from spreading by not picking at them. Consider covering warts with bandages. In addition, keep hands as dry as possible -- warts are harder to control in moist environments. You should never brush, comb, or shave areas where warts are present as this can cause the virus to spread. Wash hands thoroughly after touching any warts.
To prevent genital warts, some of the steps you can take include: