Warts are growths on the skin caused by the human papillomavirus (HPV). Warts are very common, particularly in school-age children. Warts can spread by direct contact to other parts of the body, or to others. They are usually painless, but are occasionally painful, especially when they appear on the soles of the feet.
Types of Warts
- Common warts (verruca vulgaris) can appear anywhere on dry skin, but they are more commonly seen on the hands. They can appear in clusters, known as mosaic warts.
- Flat warts are often located on the face or legs. They are smaller and can be difficult to see. They tend to grow in large numbers, 20-100 at any one time.
- Plantar warts are located on the soles of the feet. These may be painful.
Warts are usually skin-colored and feel rough to the touch, but they can be dark, flat, and smooth. The HPV virus enters the skin through a small scratch or wound. This explains why warts often appear around fingernails where the skin is often dry or cracked. After the skin becomes infected by the HPV virus, skin cells start reproducing more rapidly. This creates small bumps where the skin becomes a bit thicker than the surrounding skin.
Most people who are exposed to the HPV virus do not develop warts. Warts can passed from person to person, sometimes indirectly. However, the risk of catching hand, foot, or flat warts from another person is small. The time from the first contact to the time the warts have grown large enough to be visible is often several months.
Warts tend to heal on their own within a few years, once the body's immune system recognizes the virus as foreign and starts to attack the underlying infection. However, warts can also be removed. Warts have a tendency to return, so repeated treatments may be necessary. Common treatments include:
- Occlusion—covering the wart in a bandage or strip of tape
- Over the counter medications (salicylic acid)
- Cryotherapy (freezing off)
- Electrosurgery (burning off)
- Prescription medications
- Other treatments for hard to heal cases