A wart is an infection caused by a virus, which can invade your skin through small cuts or breaks. Over time, the wart develops into a hard, rough growth on the surface of the skin. A wart is most commonly seen on the bottom of the foot (plantar wart), but can also appear on the top. Children, teens, and people with allergies or weakened immune systems are more vulnerable to the wart virus.
Symptoms
Warts may appear spongy, with tiny red, brown, or black spots. They can grow up to an inch or more across, occuring alone (solitary) or with smaller warts clustered nearby (mosaic). Warts are sometimes mistaken for corns or calluses. They can persist for years and recur in the same spot. If left untreated, warts can spread to other parts of the foot or even to the hands or other areas of the body.
Evaluation
Your podiatrist examines your wart carefully to determine that it is not a corn or callus. A wart will usually feel painful when your podiatrist squeezes it from side to side. To examine the wart further, the hard skin layer around it may need to be trimmed. A wart will have certain spots that bleed when trimmed; a callus will not.