What Causes Warts?
Warts are skin infections caused by tiny germs called viruses of the human papillomavirus (HPV) family that get into your skin. The infected skin thickens and blood vessels flow into it, forming a raised growth. If you scratch open a wart, the viruses can spread to other parts of your body and even to other people.
After a wart stops growing, it is likely to dry up and fall off, leaving no trace. This tendency to disappear has given rise to many superstitions that warts can be charmed away with magic. And of course, you can’t get warts by touching a toad!
More common in kids than in adults, warts can affect any area of the body, but tend to invade warm, moist places, like small cuts or scratches on the fingers, hands, and feet. Warts are usually painless unless they’re on the soles of the feet or another part of the body that gets bumped or touched all the time.
Kids can pick up HPV — and get warts — from touching anything someone with a wart has used, like towels and surfaces. Kids who bite their fingernails or pick at hangnails tend to get warts more often than kids who don’t because they can expose less-protected skin and create open areas for a virus to enter and cause the wart.
Types of warts include:
Common warts. Usually found on fingers, hands, knees, and elbows, a common wart is a small, hard bump that’s dome-shaped and usually grayish-brown. It has a rough surface that may look like the head of a cauliflower, with black dots inside.
Flat warts. These are about the size of a pinhead, are smoother than other kinds of warts, and have flat tops. Flat warts may be pink, light brown, or yellow. Most kids who get flat warts have them on their faces, but they can also grow on arms, knees, or hands and can appear in clusters.
Plantar warts. Found on the bottom of the foot, plantar warts can be very uncomfortable — like walking on a small stone.
Filiform warts. These have a finger-like shape, are usually flesh-colored, and often grow on or around the mouth, eyes, or nose.