What’s the problem?

A plantar wart is a small skin lesion that resembles a callus and is found on the bottom of the foot or toes. The term “plantar” doesn’t mean only farmers get them. “Plantar” means they occur on the bottom surface of the foot. It is usually under 1 cm in diameter, but can occur in clusters and be much larger. Sometimes a single larger wart is surrounded by many smaller warts. In this case, they are called mosaic warts.

How does it feel?

WartsA plantar wart feels like a lump under the foot. They are only painful when squeezed or pinched from side to side, or if you bear direct weight on them. Warts on other parts of the body, such as the hands, grow elevated above the skin’s surface. We bear weight on warts on the bottom of the foot, so they get flattened and pushed into the skin. Most people contribute this to walking with a rock attached to the foot, as the thickened tissue becomes hard and painful as it gets bigger.

Let’s do a test!

A plantar wart can usually be diagnosed by your doctor based on a characteristic appearance alone. When the doctor trims the hard tissue from the surface of the wart, a pattern of small black dots (which are actually small blood vessels that feed the wart) can usually be seen. The doctor will also test the wart by pressing directly down on it, and then pinching it, squeezing it from side to side. Most warts won’t hurt when pressed directly down, but are very painful when pinched. If these findings are present, no further testing is necessary to identify a plantar wart.

How did this happen?

All warts are caused by the papilloma virus, a slow-growing virus which invades the skin. The viruses are common in all environments and they don’t readily grow on intact skin. But if there is a break in the skin, like a scratch or thorn penetration, this gives the virus the opportunity to get in and start growing.

The virus only grows in the epidermis, the thick layer of the skin closest to the surface. It doesn’t invade the dermis, the deeper layer of the skin. However, the epidermis and the dermis are closely entwined, and the dermis under the wart grows extra blood vessels and nerves in response to the virus infected cells above it in the epidermis. It is because of these nerves that the wart hurts when pinched, and because of these blood vessels that it stays well nourished enough to grow. The virus particles can spread from the main wart, along the cutaneous (skin) nerves, to begin growing remote or satellite warts at a distance from the original site. If enough of this spread occurs, mosaic warts result.

The wart virus thrives in the dark, moist areas such as pool areas, bath tubs, and hot tubs. It is highly recommended to wear sandals in this area to prevent contamination. Warts are contagious! Keep your feet clean and dry. Inspect your feet frequently!