What Are Plantar Warts?
Plantar warts are warts that develop on plantar surfaces -- that is, the soles (or bottom) of the feet. Normal standing and walking tends to force them into the skin, and the pressure causes pain to the affected area. Calluses formed by the body’s attempt to prevent spread of warts can also cause pain when walking. Plantar warts are harmless and may go away even without treatment, but in many cases they are too painful to ignore. Plantar warts that grow together in a cluster are known as mosaic warts.
What Causes Plantar Warts?
Plantar warts, like all warts, are caused by a virus that invades the skin through tiny cuts or scrapes. The warts may not appear for weeks or months after the initial exposure. Like other viral infections, plantar warts are contagious, and commonly spread in public swimming pools, communal showers, or even your shower at home. Epidemics of plantar warts sometimes break out among people who share gym or athletic facilities or who engage in group activities where bare feet are the rule, such as yoga and martial arts. Because most people build immunity to the virus with age, plantar warts are more common in children than in adults. They also are common in people who have weak immune systems, such as those with HIV/AIDS and taking corticosteroid or immunosuppressive medication.