Plantar warts are noncancerous skin growths on the soles of your feet caused by the human papillomavirus (HPV), which enters your skin through small or invisible cuts and abrasions. They're one of the most common warts seen by doctors.
Most plantar warts aren't a serious health concern, but they may be bothersome or painful, and they can be resistant to treatment. You may need to see your doctor to remove them.
Signs and symptoms
Plantar warts are often mistaken for corns or calluses. To make the distinction, look for:
Small, fleshy, grainy bumps on the soles of your feet
Hard, flat growths with a rough surface and well-defined boundaries
Gray or brown lumps with one or more black pinpoints, which are actually small, clotted blood vessels, not "wart seeds"
Bumps that interrupt the normal lines and ridges in the skin of your feet
A single wart or a larger wart with several smaller warts around it, commonly called mother-daughter warts.
You acquire plantar warts through direct contact with HPV. The virus isn't highly contagious, but it thrives in warm, moist environments, such as shower floors and locker rooms. That's why people may contract plantar warts by walking barefoot in public places.
Like other infectious diseases, HPV may also pass from person to person. If you have a plantar wart, you can even spread the virus to other places on your own foot or body, by touching or scratching. The virus can also spread by contact with skin shed from a wart or blood from a wart.
Each person's immune system responds to warts differently, so not everyone who comes in contact with HPV develops warts. Even people in the same family react to the virus differently. That's why parents and kids don't necessarily spread warts by sharing the same shower.
Generally, the incubation period — the time from when you're initially infected until warts appear — is about three months, but the virus can lie dormant in your skin cells for years.
These ugly bumps are more likely to appear on the feet of people with:
For reasons doctors don't understand, some people are more susceptible to the wart-causing virus, just as some people are more likely to catch a cold. Children and teenagers tend to be especially vulnerable to warts.
When to seek medical advice
Plantar warts can be difficult to get rid of. See your doctor if warts persist, multiply or recur, despite home treatment, or if warts interfere with your activities.
In some cases, you may also need to consult your doctor to ensure a correct diagnosis. It's possible for more serious lesions to crop up on your feet, including cancerous tumors called carcinomas and melanomas. If you can't confidently identify your lump, have your doctor take a look.