Verruca, or plantar warts, are caused by the Human Papilloma Virus (HPV) and are contagious. They appear to be small, hard lumps of skin and may have black spots. The virus penetrates the body through a lesion or crack in the skin.
They are commonly found on the soles of the feet or toes and can be painful if they are in an area of high pressure. The virus thrives in warm, moist environments, such as the area around a swimming pool/communal showers. Most people experience verruca at some point in their lives.