Warts are benign (not cancerous) growths caused by a virus that has infected the top layer of skin. The virus that causes warts is the human papillomavirus (HPV). Warts are most likely to occur if you have cut or damaged your skin in some way, making it easier for the virus to infect your skin. Warts are contagious and can be spread by contact with the wart or with something that the wart has touched.
Anyone can get warts. However, there are some people who are more prone to developing warts, including, people who bite their nails or pick at hangnails, children and teens, and people with weakened immune systems.
In children, warts often will go away without treatment. In adults, warts may not disappear as easily as they do in children. In some cases it is recommended to have treatment for painful or quickly multiplying warts.
Cryotherapy: This treatment is also known as freezing the wart. Liquid nitrogen is sprayed from a canister onto the wart. This treatment can be uncomfortable, especially for children. It is common to need multiple treatments for the wart to disappear.