The true plantar wart is caused by a virus that overtakes normal skin reproduction within the outer layer of skin, the epidermis. The growth becomes painful when the body forms a capsule around the lesion. This can be especially annoying on the bottom of the foot. Sometimes warts grow in clusters called mosaic warts. The body's immune system ignores the invaders and frequently allows the warts to grow and multiply.

Many treatments have been advocated for warts including over-the-counter acid treatments, cold nitrogen application, electric needle, various chemical injections, curettage (scooping the wart out), and two laser treatments. The first laser utilized to treat warts is the CO2 laser, whose target is the water in the wart cells. After anesthetizing the area, the podiatrist lasers the warts, and the cells burst with a plume of smoke and steam traveling to a vacuum hose. The second laser is called pulse-dye (yellow flash lamp). This laser targets the red color in the little blood vessels of the warts. A mild sunburn effect is encountered, but the patient may return to work the day after this treatment.

Podiatrists in most states are also licensed to treat warts of the hand by similar means.