Plantar warts occur due to a viral infection caused by human papillomavirus, or HPV, usually at the bottom of the foot. HPV is a common sexually transmitted infection that is spread though contact with infected people, and there are more than 100 different kinds of HPV, but only some of them cause warts on the feet. Warts are usually not harmful and can go away after two years without any treatment.
Warts are usually small in size but can grow bigger and in clusters, commonly referred to as mosaic warts. Plantar warts are common in children and can be spread from one person to another indirectly. For example, the warts can be transmitted through sharing a shower with an infected person without wearing shower shoes. The virus can get into the body through cracks and cuts in the skin. However, the risk of getting plantar warts from another person is minimal.
Moreover, getting plantar warts depends on a person's immune response. People with poor immune response are more vulnerable to the disease when they come in contact with infected people. Also, people with family members suffering from plantar warts may react differently. The strains that cause plantar warts are not very contagious, so direct transmission is rare. It is advisable not walk around locker rooms and swimming pools barefoot.