Plantar warts are common warts that affect the bottom of the feet. Most people will have one at some point in their lives. Plantar warts, officially named verrucae warts, are caused by human papillomavirus (HPV). The virus attacks the skin on the bottom of the feet.
HPV thrives in warm, moist places, such as locker room floors and around swimming pools. Those little puddles on the surface of pool tiles are a breeding ground for HPV. The virus is transmitted by direct contact and may be picked up more easily if you have an opening or crack in your skin.