A wart is a harmless skin growth caused by the virus called the human papillomavirus (HPV). There are more than 100 known types of HPV. HPV infects the top layer of skin, usually entering the body in an area of broken skin. The virus causes the top layer of skin to grow rapidly, forming a wart. Most warts go away on their own within months or years.

Warts can grow anywhere on the body. They are most common among children and young adults.

• • Common warts grow most often on the hands, but they may be anywhere on the body. They are rough, shaped like a dome, and grey-brown in colour.

• • Plantar warts grow on the soles of the feet. They look like hard, thick patches of skin with dark specks. Plantar warts may cause pain when you walk, and you may feel like you are stepping on a pebble.

• Flat warts usually grow on the face, arms, or legs. They are small (usually smaller than the eraser on the end of a pencil), have flat tops, and can be pink, light brown, or light yellow.

• • Filiform warts usually grow around the mouth, nose, or beard area. They are the same colour as your skin and have growths that look like threads sticking out of them.

• Periungual warts grow under and around the toenails and fingernails. They look like rough bumps with an uneven surface and border. They can affect nail growth.