A wart typically starts as a small, firm bump that feels slightly rough to the touch and looks flesh-colored or slightly lighter than the surrounding skin. In its earliest stage, it can be as small as a pinhead, making it easy to mistake for a pimple, a callus, or just dry skin. What sets a wart apart, even early on, is its texture: the surface has a grainy, slightly irregular quality that a pimple or callus won’t have.
How the Virus Gets In
Warts are caused by the human papillomavirus (HPV), which enters the skin through tiny cuts, scrapes, or areas of friction you might not even notice. The virus needs to reach the deepest layer of the outer skin, where cells are actively dividing. A micro-abrasion, something as minor as a hangnail or a shaving nick, is enough to expose that layer and let the virus latch on.
Once inside, HPV hijacks the skin’s growth process and causes cells to multiply faster than normal. But this doesn’t produce a visible bump right away. The incubation period ranges from one to 20 months, with most warts appearing two to three months after exposure. That long delay means you’ll rarely be able to trace a wart back to a specific moment of contact.
What a Common Wart Looks Like Early On
Common warts are the type most people picture. They show up most often on the fingers and hands, starting as a small, round bump with a rough, grainy surface. Early on, the color is usually close to your natural skin tone, though it may appear slightly paler or more yellowish. As the wart matures, the surface gets rougher, sometimes developing a cauliflower-like texture.
One of the most reliable signs that a bump is a wart and not something else is the appearance of tiny black dots. These are clotted blood vessels, sometimes called “wart seeds,” and they look like a sprinkling of dark pinpoints across the surface. They may not be visible in the first few days, but as the wart establishes its own blood supply, these dots become easier to spot, especially if you look closely or use a magnifying glass.
Early Plantar Warts on the Feet
Plantar warts grow on the soles of your feet, and because body weight presses them inward, they look different from warts on your hands. Instead of rising above the skin, a plantar wart often appears as a small, rough patch that feels like you’re standing on a pebble. A thick layer of hardened skin (callus) frequently forms over the top, which can make the wart itself hard to see.
The most useful early clue is disrupted skin lines. The natural ridges on the bottom of your foot, similar to fingerprints, flow in continuous patterns. A plantar wart interrupts those lines. If you see an area where the ridges seem to go around a central spot rather than through it, that’s a strong indicator. Black pinpoint dots are also common in plantar warts and serve as another distinguishing feature. On darker skin tones, the growth may appear lighter than the surrounding skin.
Flat Warts and Filiform Warts
Not all warts start as rough bumps. Flat warts are smaller and smoother, with a surface that sits nearly level with the skin. They tend to appear in large clusters, sometimes 20 to 100 at a time, which can make them look like a rash. The bumps may be skin-colored, pink, brown, or purplish. Children often develop them on the face, particularly on the cheeks or forehead. Adults tend to get them in areas where they shave, like the chin, legs, or bikini line, because the razor creates the micro-abrasions the virus needs.
Filiform warts look nothing like the classic wart. Instead of being round and bumpy, they have long, narrow projections that stick out from the skin, almost like tiny threads or fingers. They grow quickly compared to other types and typically appear on the face: around the mouth, eyes, or nose. Their color varies widely and can match your skin tone or appear yellow, pink, white, gray, or brown. Unlike flat warts, filiform warts don’t form clusters. They usually show up one at a time.
How to Tell a Wart From a Corn or Callus
On the feet especially, early warts are frequently confused with corns and calluses. All three involve thickened, hardened skin, but they differ in important ways.
- Corns develop from repeated pressure or friction, usually on the toes. They have a hard center surrounded by inflamed skin and no black dots. The skin lines pass through them normally.
- Calluses form on weight-bearing areas like the heels or balls of the feet. They’re broader and flatter than warts, with smooth, even thickening. Again, no black dots and no disruption of skin lines.
- Warts have a grainy texture, may show black pinpoint dots, and interrupt the natural ridges of the skin. Squeezing a plantar wart from the sides typically causes pain, while pressing directly down on a callus is what hurts most.
That squeeze test is a quick way to check at home. Pinch the suspicious spot between your thumb and finger from the sides. If that’s more painful than pressing straight down, it’s more likely a wart.
What Happens as a Wart Grows
In the first few weeks, a wart is small enough that you might ignore it or assume it will go away on its own. Over the following weeks to months, it gradually gets larger, rougher, and more raised. The black dots become more visible as the wart develops its network of blood vessels. Common warts can eventually reach the size of a pencil eraser or larger, though many stay smaller.
Warts can also spread. Touching or picking at a wart and then touching another part of your body can transfer the virus. Plantar warts may multiply into clusters called mosaic warts if left untreated. Flat warts are especially prone to spreading across a wider area because shaving or scratching can drag the virus along the skin.
Many warts do eventually clear on their own as the immune system recognizes and fights the virus, but this can take months or even years. Treating a wart when it’s still small is generally easier and faster than waiting until it’s well established.