Quick Summary
- Plantar warts are caused by HPV and often have tiny black dots (clotted blood vessels) visible in the center.
- Corns form from repeated friction or pressure and have a smooth, waxy core with no black dots.
- Warts interrupt normal skin lines; corns and calluses follow the skin's natural print pattern.
- Warts are contagious and can spread to other parts of the foot or to other people; corns are not contagious at all.
- Squeezing a wart from the sides is painful; squeezing a corn from the sides typically isn't — pressing straight down hurts both.
Warts and corns both show up as hard, sometimes painful bumps on the feet, and the confusion is understandable — they can look remarkably similar at first glance. But one is a viral infection and the other is a mechanical response to pressure, and telling them apart changes how you treat it.
What a Plantar Wart Is
A plantar wart is caused by the human papillomavirus (HPV) entering the skin through small cuts or breaks, usually on the sole of the foot. It often looks like a rough, grainy bump with tiny black or brown dots inside it — those dots are small clotted blood vessels, and they're one of the clearest visual clues that you're looking at a wart rather than a corn. Warts also tend to disrupt the normal ridges and lines of the skin (your natural "fingerprint" pattern continues on skin, but stops or distorts over a wart). Because they're viral, warts are contagious through direct contact or shared surfaces like locker room floors and pool decks.
What a Corn Is
A corn is a thickened, hardened area of skin that develops in response to repeated friction or pressure — most often from ill-fitting shoes or an abnormal way of walking that puts uneven pressure on one spot. Corns have a smooth, waxy-looking central core and no black dots, and the natural skin lines continue right over the top of them uninterrupted. Corns are not contagious and won't spread to other parts of the body or to other people.
Key Differences at a Glance
| Feature | Plantar Wart | Corn |
|---|---|---|
| Cause | HPV infection | Friction or pressure |
| Black dots | Often present (clotted vessels) | Never present |
| Skin lines | Interrupted or distorted | Continue uninterrupted over the top |
| Contagious? | Yes | No |
| Side-pinch test | Painful | Usually not painful |
A Simple At-Home Clue
One commonly used trick: gently pinch the lesion from the sides (not straight down). Warts tend to be tender or painful with a side pinch because of the disrupted blood vessels underneath; corns generally aren't. It's not foolproof, but it's a useful clue while you decide whether to seek treatment.
Dealing with a stubborn bump on your foot?
Our board-certified dermatologists see patients at our Burien and Bellevue offices — same-week appointments are often available.
Schedule a Skin CheckWhen to See a Dermatologist
Over-the-counter treatments can work for both, but if a spot isn't improving after several weeks of home care, is spreading, or you're simply not sure what you're dealing with (especially with diabetes or poor circulation, where foot issues need extra caution), it's worth having it evaluated and treated properly rather than continuing to guess.