Warts are non-cancerous skin growths caused by a viral infection in the top layer of the skin. Viruses that cause warts are called human papillomavirus (HPV). The types of HPV that cause common warts, plantar warts, or flat warts are usually different from the types of HPV that cause genital warts. A vaccine is available to help protect against the types of HPV that cause genital warts (and increase a person's risk of certain types of cancer).
There are several different kinds of warts including:
Common warts usually grow on the fingers, around the nails and on the backs of the hands. They are more common where skin has been broken, for example where fingernails are bitten or hangnails picked. These are often called "seed" warts because the blood vessels to the wart produce black dots that look like seeds.
Foot warts usually appear on the soles (plantar area) of the feet and are called plantar warts. When plantar warts grow in clusters they are known as mosaic warts. Most plantar warts do not stick up above the surface like common warts because the pressure of walking flattens them and pushes them back into the skin. Like common warts, these warts may have black dots. Plantar warts are uncomfortable and painful, feeling like a stone in the shoe.
Flat warts appear as small, smooth usually skin colored, pink or brown bumps on the skin. Common places for flat warts are the face, top of the hands, top of the feet, arms, and legs.
Genital warts (warts in the genital area, also called "condyloma acuminatum"
To prevent warts from spreading, dermatologists recommend the following:
While you can often clear a wart at home, some warts can be stubborn. If the person has a weakened immune system, it can be difficult to get rid of warts. Sometimes, what looks like a wart turns out to be a callus or another type of growth.
A board-certified dermatologist can help by:
Sometimes, warts can be stubborn, so they don’t clear with treatment that you can buy without a prescription. A dermatologist can create an effective treatment plan.