Keloid Photos: What They Are & What Causes Them

Keloids are raised, firm scars that grow beyond the edges of the original wound and do not fade on their own over time. Unlike ordinary scars, which gradually flatten and lighten, a keloid keeps producing scar tissue long after the skin has healed, creating a rounded, often shiny mass that can be much larger than the injury that triggered it. If you are comparing a mark on your skin to photos online, the single most telling feature is that boundary overgrowth: a keloid spills past where the cut, burn, or piercing was, sometimes dramatically so.

What Keloids Actually Look Like

Keloids typically appear as firm, smooth, dome-shaped or irregularly shaped nodules that rise above the surrounding skin. The color ranges from pink or red in lighter skin tones to dark brown or purplish in darker skin. Many have a glossy, almost polished surface, and larger ones can develop a lumpy, lobulated shape with multiple rounded lobes merging together. Some keloids are relatively small, like a pea-sized bump near an earlobe piercing, while others stretch across several centimeters on the chest, shoulder, or upper back.

Texture is another distinguishing feature. Keloids feel rubbery to firm when pressed, and the tissue inside them is dense with thick, tightly packed collagen fibers surrounded by extra cellular material that normal scars lack.¹ They do not indent easily and spring back when you release pressure. Some are flat enough to look like a wide stain on the skin, but most have noticeable height. Early keloids can be softer and redder; older ones tend to harden and darken.

Keloids Versus Hypertrophic Scars

The comparison people struggle with most is between a keloid and a hypertrophic scar, because both are thick, raised, and reddish. The critical difference is boundary behavior. A hypertrophic scar stays within the borders of the original wound: if you had a two-centimeter incision, the raised scar is roughly two centimeters wide. A keloid invades normal skin beyond those borders.² That spreading is the hallmark. A keloid from a small earlobe piercing, for example, can grow into a ball that dwarfs the original puncture site.

There are also differences in trajectory. Hypertrophic scars often improve over months to years, gradually softening and flattening. Keloids do not regress with time and are notoriously difficult to remove surgically, because cutting them out frequently triggers a new, sometimes larger keloid.¹ Hypertrophic scars can also cause contractures, pulling the surrounding skin tight, while keloids generally do not.³

What Triggers Keloid Formation

Almost any injury to the skin can start a keloid in someone who is susceptible. Surgical incisions, burns, acne, ear or body piercings, vaccinations, tattoos, and even minor scratches or insect bites have all been documented as triggers.⁴ The severity of the injury does not reliably predict the severity of the keloid. A tiny piercing hole can produce a keloid the size of a grape, while a large surgical incision might heal with only minor scarring in the same person.

Skin tension and mechanical forces play a surprisingly important role. Keloids tend to form in areas where the skin is constantly being stretched or pulled during everyday movement. Research comparing keloid-prone body sites with the amount of strain those sites experience during normal activity found a strong correlation: areas under high tension, like the chest, shoulders, and upper back, produce keloids at much higher rates than low-tension areas.⁵ This helps explain why earlobes are also a common site, since earrings tug on healing tissue and create chronic low-grade strain.

Why Certain Body Areas Are More Prone

If you look at large collections of keloid cases, the chest, ears, shoulders, and upper back dominate. A large demographic analysis found the chest was the single most common keloid location among Asian, white, and multiracial patients, while the ear was the most common site among Black patients.⁶ The back and shoulder/deltoid area rounded out the top sites across all groups studied.

The structural explanation has to do with how the skin is built in those zones. Keloid-prone areas tend to have high baseline skin tension, low stretchiness, and a low elastic modulus compared to keloid-resistant areas. Bony prominences and cartilage pushing into the dermis from below add internal stress, and the bundled arrangement of collagen in the deeper layers of skin at these sites amplifies mechanical forces during movement.⁷ In practical terms, this means a wound on your sternum faces a far more hostile healing environment than the same wound on your calf or forearm.

Who Is at Risk

Keloid susceptibility has a strong genetic component. Family studies have found a pattern consistent with a dominant mode of inheritance, meaning you can carry the predisposition from one parent alone, though not everyone who carries the relevant gene variants will actually develop keloids.⁸ Multiple gene regions across several chromosomes have been linked to keloid risk, and the picture is complex, with different populations carrying different susceptibility variants.⁹

Ethnicity is a well-established risk factor. People of African, Asian, and Hispanic descent develop keloids at substantially higher rates than people of European descent, though keloids can and do occur in every ethnic group. The demographic analysis cited earlier found that Black patients made up a much larger share of the keloid population relative to their share of either the general dermatology population or the broader patient base.⁶ Black patients were also more likely to have larger keloids at diagnosis and to have keloids at multiple sites.

Age and hormones matter too. Keloids most commonly develop between puberty and age 30, and they are uncommon in young children and older adults. Pregnancy and puberty can both trigger the growth of new keloids or the enlargement of existing scars. Clinicians have documented cases of stable scars transforming into keloids during puberty, likely driven by the hormonal changes of that period.¹⁰

What Is Happening Inside the Skin

Normal wound healing involves a controlled cycle of inflammation, new tissue production, and remodeling. In a keloid, that cycle never properly shuts off. The result is chronic inflammation in the deeper layers of the skin, which drives continuous scar tissue production and the characteristic invasive growth.¹¹

A growth factor called TGF-beta is central to the problem. Fibroblasts, the cells responsible for making collagen, are abnormally sensitive to TGF-beta in people who form keloids. When exposed to this signal, keloid fibroblasts produce significantly more collagen than normal skin fibroblasts do, and they also ramp up their own growth rate.¹² The fibroblasts also carry more receptors for TGF-beta on their surface, which amplifies the signal further and creates a self-reinforcing loop of overproduction.¹³

Low oxygen levels inside the growing scar tissue add fuel to this process. Keloid tissue tends to be oxygen-poor compared with normal skin, and that hypoxic environment pushes normal fibroblasts toward a more aggressive, scar-producing state through the same TGF-beta signaling pathway.¹⁴ In other words, as the keloid grows and its blood supply becomes less adequate, the resulting oxygen deficit makes the cells inside it even more fibrotic, perpetuating the growth cycle.

Itch, Pain, and Nerve Changes

Keloids are not just a cosmetic concern. Many are genuinely uncomfortable. Itching and pain are among the most frequent complaints, and research has tied these symptoms to actual changes in small nerve fiber function within the scar tissue. Patients with keloids show abnormal thresholds for sensing warmth, cold, and heat pain in the affected area, and the intensity of itch correlates with those nerve abnormalities.¹⁵ The itch can be relentless, and because scratching a keloid risks further skin trauma, it puts susceptible people in a frustrating loop.

Some keloids also cause a pulling or tightness sensation, particularly on the chest or neck, and larger ones on joints can restrict range of motion. These physical symptoms alone are often enough to drive people to seek treatment, even if the appearance of the scar does not bother them.

The Emotional and Social Toll

Keloids affect quality of life in ways that extend well beyond the physical. A comprehensive review identified seven interacting domains of impact: pain and itch, mobility limitations, visibility, gender- and age-related concerns, psychosocial distress, stigma, and cosmetic dissatisfaction.¹⁶ People with keloids in visible areas, such as the face, neck, or hands, report higher levels of anxiety, depression, and sensitivity about social interactions compared to those with keloids hidden under clothing.¹⁷

Stigma is a particular issue. In some communities, visible keloids prompt unwelcome questions or assumptions about injuries, and people may alter their clothing, hairstyles, or social habits to avoid exposure. For younger patients who develop keloids during adolescence, the emotional impact can be especially acute at a time when body image is already fragile.

When a “Keloid” Might Be Something Else

Not every raised, firm lump on the skin is a keloid. A four-year study of patients who came in self-diagnosed with a keloid or hypertrophic scar found that about one in a hundred actually had a different condition entirely, including benign tumors and chronic infections that mimicked the appearance of a keloid.¹⁸ Certain malignant tumors can also look similar, which is why dermatologists stress the importance of having any unusual scar evaluated in person, especially if it appeared without a clear history of injury, is growing rapidly, or has features like bleeding or ulceration that keloids typically lack.

Treatment Options and Their Limitations

Keloid treatment is notoriously difficult because the same wound-healing abnormality that created the keloid can reactivate after any intervention. Current evidence supports a layered approach, starting with less invasive options and escalating as needed.

First-line treatment generally combines silicone gel sheeting with corticosteroid injections directly into the scar. Silicone sheets applied to a healing wound may also help prevent keloids in people known to be prone to them, though the evidence base for prevention is still limited in quality.¹⁹ Corticosteroid injections work by suppressing the overactive inflammatory response and reducing collagen production, but they often require multiple sessions and can cause thinning or color changes in the surrounding skin.

For keloids that do not respond to injections, several add-on therapies can be considered:

• 5-Fluorouracil: An antimetabolite drug injected into the scar to slow fibroblast growth, sometimes used alongside steroids.
• Bleomycin: Another injectable agent that can help flatten keloids, though results across studies are mixed.
• Laser therapy: Pulsed-dye or fractional lasers can reduce redness and bulk, often used in combination with topical or injected steroids to improve drug penetration.
• Pressure therapy: Custom pressure garments or earring-style clips that apply constant pressure to the scar, helping prevent recurrence after other treatments.

These therapies all have evidence behind them, but none is reliably curative on its own.²⁰

Surgical excision is reserved for keloids that are large, symptomatic, or unresponsive to injections, and it is almost never done alone. Cutting out a keloid without an adjuvant treatment has a high recurrence rate because the surgery itself creates a new wound in exactly the tissue most prone to overhealing. The standard approach pairs excision with immediate post-operative radiation therapy. Electron beam radiation and high-dose-rate brachytherapy are the two most commonly used modalities, and studies report that roughly four out of five keloids treated with surgery plus radiation do not recur.^{21 22} The word “radiation” understandably alarms some patients, but the doses used for keloids are low and targeted, and long-term studies have not shown a meaningful increase in cancer risk from this application.

A Uniquely Human Problem

One of the more unusual facts about keloids is that they appear to be exclusive to our species. No other animal naturally develops keloid scars, which has made studying them in the laboratory remarkably challenging.^{23 24} Researchers have tried transplanting human keloid tissue onto immunodeficient mice and using other creative workarounds, but these models only capture fragments of the biology. The lack of a true animal model is one reason keloid research has lagged behind work on other fibrotic conditions, and it partly explains why no single treatment reliably cures the problem. It also raises an interesting evolutionary question: what is it about human wound healing, skin structure, or immune response that allows this runaway scarring to happen when it apparently does not afflict any other mammal? That question remains open, but it underscores just how distinctive and biologically peculiar keloid formation really is.