Plantar warts are common, especially in children. Plantar warts appear on the bottom of the feet. Virtually everyone will have a wart (or several) someplace at some time in their lives.
Plantar warts are noncancerous skin growths, caused by a viral infection in the top layer of the skin. The culprit is a strain of virus called human papillomavirus or HPV. Many strains of the virus exist, and those that cause common warts on the hands and feet are not the same strains of HPV that cause genital warts.
Some people mistakenly think plantar warts are malignant. In fact, they are not harmful. Eventually, in about two years, most warts go away without treatment. Warts can, however, cause irritation or minor pain, depending on their location. Also, warts may appear unsightly and make the person who has them self-conscious.
On average plantar warts are small, about the size of a pencil eraser. But some warts grow bigger. Sometimes plantar warts can grow in clusters called mosaic warts.
Sometimes corns or calluses are mistaken for plantar warts. In some warts, little black dots appear, leading people to call them "seed" warts. The black dots are actually little blood vessels that have grown up into the wart.
Plantar warts usually don't stick up above the skin as much as warts on the hand, partly because of the pressure of walking and it's flattening effect.
Warts are spread from person to person. The transmission can be indirect. For instance, a person with a plantar wart uses a shower without wearing shower shoes and another person then uses it and develops a wart. The risk of this happening is small though.
A person's risk of getting a wart varies. Those with a weakened immune system are more susceptible.
Doctor's treatments include freezing the wart off with liquid nitrogen, removing the wart with laser or surgery, or applying or injecting medicines to strengthen the immune system so it can clear your body of the virus.