Verrucas are a type of wart virus that affects the soles of the feet. They are extremely contagious and can be painful if left untreated. Verrucas may start as small dots on the foot and grow into raised, rough, bumpy warts. If you have multiple verrucas growing together, these are known as mosaic warts.
Veruccas are caused by the Human Papiloma Virus (HPV) and are contagious. They are usually transmitted through direct contact (or by stepping somewhere where someone infected with the virus has been, such as a shower or swimming pool floor). They get through the skin via tiny cuts or abrasions on the bottom of the foot and it can take some weeks or even months for them to appear after the infection has been caught. Most people build up and immunity to them with age so they are more common in children.
Verrucas are found only on the bottom of the feet. They are also known as "plantar warts", plantar meaning "relating to the sole of the foot".
Anyone can contract a verruca however they are far more widespread in children and those who use communal facilities such as gyms and swimming pools where people are walking around bare foot.