Warts

What Is It?

Warts are small skin growths caused by the human papilloma virus (HPV), which infects the top layer of skin. There are more than 40 different types of HPV. It can be transmitted from one person to another either by direct contact, or indirectly when both people come in contact with a surface, such as a floor or desk. People may come into contact with HPV by walking barefoot in public places, such as gyms and shower floors. HPV also can be transmitted in the same person from one spot on the body to another. It is easier for HPV to infect a person when the person's skin is scratched or cut.

Warts can appear at any age but are more common in older children and are uncommon in the elderly. A wart's appearance varies with its location and the type of virus that has caused it. For example, flat warts commonly appear on the face, neck, chest, forearms and legs. Most warts go away after a year or two, but some last for years or come back after going away.

Warts can itch or bleed. When warts are located in areas that are rubbed against clothing or bumped frequently, they can become irritated and the skin around them can become painful. Warts are not cancerous.

Symptoms

The two types of warts seen most often are common warts and plantar warts.

• Common warts have a rough surface and well-defined borders. They are round or irregular in shape and range from 2 millimeters to 10 millimeters wide (the size of a pencil eraser or smaller). Common warts are firm and can be light gray, yellow, brown or gray-black. They occur most often near the fingernails and on the backs of the hands, but they also can appear on the elbows and knees. Common warts usually do not hurt.

• Plantar warts appear on the bottom (sole) of the foot. They are flattened by the pressure of standing on them and can be dotted with tiny, clotted blood vessels that look like dark pinpoints. Plantar warts often are painful, especially when they're on a weight-bearing part of the foot. Corns look different than plantar warts because they don't have the pinpoint dark spots. Plantar warts may require vigorous, repeated treatment before they go away.