Most foot warts are harmless, even though they may be painful. They are often mistaken for other conditions such as corns or calluses which are layers of dead skin that build up to protect an area which is being continuously irritated]. A wart, however, is a viral infection. Over 42 types of viruses are known to cause a wart.
More serious foot lesions such as malignant (cancer) lesions can sometimes be mistaken as a wart. Children, especially teenagers, tend to be more susceptible to warts than adults while some people seem to be immune. The most common times for warts to occur are, puberty, emotional & physical stress, pregnancy and menopause.
Warts can appear anywhere on the skin and those which are located on the sole of the foot are called plantar warts. The virus generally invades the skin through small or invisible cuts and abrasions. When they get large enough they can be quite painful.
Plantar warts appear to be hard and flat, with a rough surface and well-defined boundaries but their true size is hidden because they are pushed into the skin. Warts are generally raised and fleshier when they appear on the top of the foot or on the toes. Plantar warts are often gray or brown (but the color may vary), with a center that appears as one or more pinpoints of black.
The plantar wart is often contracted by walking barefoot on contaminated surfaces. The virus that causes plantar warts thrives in warm, moist environments, making infection a common occurrence in public bathing facilities, locker rooms and even can be transmitted when trying on a pair of shoes.
If left untreated, warts can grow to an inch or more in circumference and can spread into clusters of warts. Like any other infectious lesion, plantar warts are spread by touching, scratching, or even by contact with skin shed from another wart. The wart may also bleed, another route for spreading.
Plantar warts that develop on the weight-bearing areas of the foot – the ball of the foot, or the heel, can cause sharp, burning pain. Pain occurs when weight is brought to bear directly on the wart, although pressure on the side of a wart can create equally intense pain.