A keloid is a thick, raised scar that grows beyond the edges of the original wound. Unlike a normal scar, which stays flat and fades over time, a keloid keeps expanding into surrounding healthy skin, sometimes for months or years after the injury has healed. About 86% of people with keloids experience itching, and nearly half report pain at the scar site, making keloids more than just a cosmetic concern.
How Keloids Form
Every time your skin is injured, your body sends specialized cells called fibroblasts to the wound to produce collagen, the protein that knits tissue back together. In normal healing, this process eventually shuts off. With keloids, it doesn’t. The fibroblasts become overactive: they multiply faster, survive longer, and resist the natural cell death signals that would normally tell them to stop working.
The result is dramatic. Collagen production in a keloid is roughly 20 times greater than in healthy skin and three times greater than in an ordinary raised scar. Two specific growth signals drive the process, recruiting more fibroblasts to the area and pushing them to keep producing collagen long after the wound has closed. Under a microscope, keloid tissue looks distinct from other scars, with thick, swirling bundles of collagen packed tightly together.
Common Triggers and Locations
Keloids can develop from virtually any skin injury, including surgical incisions, burns, acne, body piercings, insect bites, injections, and even minor scratches or ingrown hairs. The earlobes, shoulders, chest, and cheeks are the most common sites, though keloids can appear anywhere on the body. Ear piercings are one of the most frequent triggers, particularly on the upper cartilage.
Not everyone who gets a skin injury develops a keloid. People with darker skin tones are significantly more likely to form them, and they tend to run in families. If you’ve had one keloid, you’re at higher risk of developing another after future injuries.
Keloid vs. Hypertrophic Scar
Many raised scars are hypertrophic scars, not keloids. The distinction matters because the two behave very differently and require different approaches to treatment.
The single most defining difference is how far the scar grows. A hypertrophic scar stays within or just at the edges of the original wound. A keloid invades horizontally into surrounding skin that was never injured. Timing also differs: hypertrophic scars typically appear within four to eight weeks of an injury, grow for six to eight months, then stabilize and often flatten on their own. Keloids can emerge anywhere from three months to several years after an injury, rarely mature, and almost never resolve without treatment.
There’s one more practical distinction. Hypertrophic scars can cause contractures, meaning the scar tissue tightens and limits joint movement. Keloids do not cause contractures, though they can be physically uncomfortable in other ways.
What Keloids Feel and Look Like
Keloids are firm, smooth, and often shiny. They can be pink, red, purple, or darker than the surrounding skin. Some are small and round, while others spread into large, irregular shapes over time. They’re raised above the skin surface, sometimes dramatically so.
The physical symptoms are more common than many people expect. In controlled studies, 86% of keloid patients reported itching and 46% reported pain at the scar site. The itching and tenderness can be persistent enough to interfere with sleep or daily activities, especially when the keloid is in an area that rubs against clothing or jewelry.
Treatment Options
Keloids are notoriously stubborn. The challenge isn’t removing them; it’s keeping them from coming back. Surgical excision alone has a recurrence rate of 45% to 100%, which is why surgery is almost always paired with an additional therapy.
Steroid Injections
Injecting a corticosteroid directly into the keloid is one of the most widely used first-line treatments. The injections soften and flatten the scar tissue by slowing collagen production. Sessions are typically spaced about a month apart, and most people need at least two or three rounds, though treatment can continue for six months or longer depending on how the keloid responds.
Surgery With Adjuvant Therapy
When a keloid is large enough to require surgical removal, adding radiation therapy afterward drops the recurrence rate substantially. A meta-analysis found that surgery followed by radiotherapy brought the recurrence rate down to about 13.5%, compared to roughly 50% with surgery alone. Another effective combination is laser treatment paired with steroid injections, which achieved a recurrence rate of about 12.2% in the same analysis.
Cryotherapy
Freezing the keloid with liquid nitrogen can shrink it over multiple sessions. Recovery rates of about 76% have been reported, though this typically requires an average of 20 sessions spaced two weeks apart. The most common side effect is changes in skin color at the treatment site, either darkening or lightening, along with occasional skin thinning.
Silicone Gel Sheets
Silicone sheets are a noninvasive option used both to treat existing keloids and to prevent them from forming after surgery. They work by keeping the scar hydrated and applying gentle pressure. Most treatment protocols call for wearing the sheets at least 12 hours per day, with some recommending up to 24 hours. Because scar remodeling is a slow process, consistent use for at least a year is generally recommended to see meaningful results.
Preventing Keloids
If you know you’re prone to keloids, the most effective prevention strategy is avoiding unnecessary skin injuries when possible. That means skipping elective piercings, being cautious with cosmetic procedures, and treating acne early before it causes deep skin damage. For unavoidable surgeries or wounds, applying silicone gel sheets as soon as the incision heals can reduce the odds of a keloid forming. Pressure garments, sometimes used after burns or major surgeries, work on a similar principle by keeping steady compression on the healing tissue.
Even minor injuries deserve attention if you’re keloid-prone. Keeping cuts clean, moisturized, and covered during healing may help reduce the inflammatory signals that kick off excessive collagen production.