The little black dots sometimes seen are the ends of blood vessels that the wart has recruited to bring it food. Even without roots, warts can be difficult to destroy. Warts are infections caused by viruses that are present everywhere, making them among the most common of all childhood skin conditions . They are spread when the virus touches a part of the skin where the outer protective layer is broken, either by minor trauma or by moisture. This happens most commonly on the fingers, elbows, knees, and the bottoms of the feet.
Some people get warts more easily than other people.
Warts are more common in children than in adults, partly because of their less mature immune systems and partly because they spend more time in wet-floored locker rooms and in active, close play. Wearing something on the feet in locker rooms and at the pool can prevent many plantar warts. Most warts will eventually go away on their own, expelled by the body's immune system. Warts will not leaves scars, though some of the more aggressive wart therapies might. Plantar warts often make running, jumping, and even walking, uncomfortable.