Warts are one of several soft tissue conditions that occur in the foot. They are often misdiagnosed as calluses. Children, especially teenagers, tend to be more susceptible to warts than adults; often this is due to a less-developed immune system. Warts often appear with very small black dots.
The virus that causes warts generally invades the skin through small or invisible cuts and abrasions. The plantar wart is often contracted by walking barefoot on surfaces where the virus is present. The virus occurs in warm moist environments such as swimming pools and showers.
If left untreated, warts can grow and can spread into clusters of several warts. Like any other infectious lesion, plantar warts are spread by touching, scratching, or even by contact with skin shed from another wart. Warts can sometimes spontaneously resolve only to recur in the same location.