Keloids and warts are both raised skin growths, but they have completely different causes, behave differently, and require different treatments. A keloid is an overgrowth of scar tissue that forms after skin injury, while a wart is a viral infection caused by human papillomavirus (HPV). This distinction matters because it changes everything about how the growth develops, whether it can spread, and how you get rid of it.
What Causes Each Growth
Keloids form when the body’s wound-healing process goes into overdrive. After any skin injury, whether a surgical cut, a burn, a piercing, or even a bad acne breakout, the body produces collagen to repair the damage. In keloid-prone individuals, that collagen production ramps up to roughly 20 times the normal level. The fibroblasts (cells responsible for building new tissue) become overactive and resistant to the signals that would normally tell them to stop. The result is a mass of dense, thick collagen that keeps growing well beyond the edges of the original wound.
Warts, on the other hand, are caused by HPV entering the skin through tiny cuts or abrasions. The virus works its way into the deepest layer of the outer skin, hijacks normal cells, and forces them to multiply rapidly. Specifically, the virus produces proteins that shut down two of the body’s key brakes on cell growth: proteins that normally repair damaged DNA and regulate cell division. With those brakes disabled, skin cells pile up into the rough, raised bump you see on the surface.
How They Look and Feel
Keloids are smooth, firm, and often shiny. They can be pink, red, or darker than the surrounding skin, and they tend to have a rubbery or hard texture. A defining feature is that they grow beyond the borders of the original wound, sometimes expanding for months or years. They may itch or feel tender, and larger keloids can become painful or restrict movement if they form near a joint.
Warts have a distinctly different texture. Common warts are rough and bumpy on the surface, almost like a tiny cauliflower. If you look closely, you may notice small dark dots inside them, which are clotted blood vessels sometimes called “seeds.” Warts also interrupt the normal skin lines (fingerprint-like ridges) on the hands and feet, which is one way dermatologists confirm the diagnosis. Plantar warts on the soles of the feet are often flat because body weight presses them inward, and they can be quite painful to walk on.
Flat warts are a less obvious variety: small, smooth-topped bumps under 5 mm across that tend to cluster in groups of dozens. Filiform warts look like tiny finger-like projections, often appearing near the eyes, nose, or mouth.
Where They Typically Appear
Keloids most commonly form on the upper body: the chest, shoulders, upper back, and earlobes. Ear piercings are one of the most frequent triggers. They can develop anywhere skin has been injured, but these high-tension areas where the skin is constantly being stretched are especially prone.
Warts can grow anywhere, but hands and feet are the most common sites. Common warts favor the backs of hands, fingers, and the skin around nails. Plantar warts develop on the soles of the feet. Flat warts tend to appear on children’s faces, men’s beard areas, and women’s legs. Genital warts are a separate category caused by different HPV strains and spread through sexual contact.
Who Gets Them
Keloid susceptibility has a strong genetic and ethnic component. People with darker skin are significantly more likely to develop them. Reported prevalence rates vary widely: roughly 8.5% in Kenya, 9% in Zambia, and as high as 16% in parts of Central Africa, compared with 0.09% in England and 0.10% in Japan. A family history of keloids is one of the strongest predictors. They can develop at any age but are most common between puberty and age 30.
Warts are far more universal. They’re caused by an extremely common virus, and most people will have at least one wart at some point in their lives, particularly during childhood. Because HPV spreads through skin-to-skin contact or contaminated surfaces (like shared towels, pool decks, or even school supplies), warts are contagious. You can also spread them to other parts of your own body through scratching or shaving. The incubation period ranges from 1 to 20 months, so a wart may appear long after the initial exposure.
Keloids are not contagious. You cannot catch one from another person or spread it to a different part of your body. They only form at sites of skin injury in people who are genetically predisposed.
Do They Go Away on Their Own?
Warts frequently do. About half of all cutaneous warts resolve on their own within one year, and roughly two-thirds disappear within two years, as the immune system eventually clears the virus. This is why many doctors recommend a “wait and see” approach for painless warts in children.
Keloids almost never resolve spontaneously. Without treatment, they tend to remain the same size or continue growing. Some may flatten slightly over many years, but meaningful shrinkage without intervention is rare.
Treatment for Warts
The most common first-line treatment for warts is salicylic acid, available over the counter in concentrations of 17% (liquid form) or 40% (adhesive patches). It works by dissolving the infected skin layer by layer. You apply it daily after soaking and filing the wart, and treatment typically takes several weeks. Higher concentrations, up to 60%, are available through a doctor.
Cryotherapy (freezing with liquid nitrogen) is the other standard option, with an overall success rate of about 75% for common warts. It often takes multiple sessions spaced a few weeks apart. Other options include prescription creams that stimulate a local immune response, and for stubborn warts, procedures like laser treatment or minor surgery.
Treatment for Keloids
Keloids are notoriously difficult to treat, and recurrence is a major challenge. The most widely used approach is corticosteroid injections directly into the keloid, typically repeated at one-month intervals. These injections reduce inflammation and promote the breakdown of excess collagen. They can be quite painful, so the needle is usually inserted at the border between the keloid and normal skin rather than into the dense center.
Cryotherapy is also used for keloids, though the success rate is lower than for warts, at roughly 51% to 74% depending on the study. Surgical removal alone is generally considered a last resort because the recurrence rate is strikingly high: 50% to 80%, with some studies reporting rates approaching 100%. The surgery itself creates a new wound, which can trigger an even larger keloid. Combining surgery with radiation therapy drops the recurrence rate to below 10%, making it a far more effective strategy for severe cases.
Silicone sheets and gels, pressure garments, and laser therapy are other options that may help flatten keloids or prevent them from forming after surgery. Treatment plans often combine multiple approaches.
The Key Differences at a Glance
- Cause: Keloids result from abnormal wound healing. Warts are caused by HPV infection.
- Contagious: Warts spread through contact. Keloids cannot be transmitted.
- Texture: Keloids are smooth and firm. Warts are rough and bumpy (except flat warts).
- Growth pattern: Keloids expand beyond the original wound. Warts stay within a defined border.
- Self-resolution: Two-thirds of warts disappear within two years. Keloids persist indefinitely.
- Recurrence after removal: Warts may return if the virus is still present. Keloids have recurrence rates of 50% to 80% after surgical removal alone.
If you’re unsure whether a skin bump is a keloid or a wart, the history is often the biggest clue. A raised growth that appeared at the site of an injury, piercing, or surgery and gradually expanded is likely a keloid. A rough, well-defined bump on the hands, feet, or face with no prior injury is almost certainly a wart. A dermatologist can confirm either diagnosis with a quick visual exam.