Not All Raised Scars Are the Same! Keloids vs Hypertrophic Scars
Sudha Mishra | Nov 03, 2026, 11:10 IST
Keloid or Hypertrophic Scar
Both keloids and hypertrophic scars rise above the skin after an injury, but they behave differently, respond to different treatments, and carry different risks if managed incorrectly. Understanding what separates them, at the tissue level, not just by appearance, changes how you approach treatment and what you can realistically expect from it.
Highlights
- Keloids and hypertrophic scars are both results of an overactive wound-healing response, but they differ in behavior and treatment; keloids extend beyond the original injury site, while hypertrophic scars remain confined.
- Individuals with darker skin tones, such as South Asian, African, and East Asian populations, are more predisposed to keloids, which can form from minor traumas like small cuts or insect bites.
- Management strategies for hypertrophic scars often involve conservative treatments like silicone gel sheets, while keloids are more complex and may require a combination of treatments, including surgical excision and intralesional corticosteroid injections.
A raised scar after a cut, piercing, or surgery is not automatically a keloid. That distinction matters more than it might seem, because the two types of raised scars, keloids and hypertrophic scars, have different biology, different boundaries, and different responses to treatment. Conflating them leads to interventions that either fail or actively make things worse.
Both scars result from an overactive wound-healing response in which fibroblasts, the cells responsible for producing collagen, remain switched on longer than they should. In a normally healing wound, collagen production ramps up and then tapers off as the wound closes. In both keloid and hypertrophic scarring, that tapering does not happen on schedule.
The difference lies in where the excess collagen goes. A hypertrophic scar stays within the original wound boundary. It may be raised, firm, and pink, but it does not spread beyond the edges of the initial injury. A keloid does not respect that boundary. It extends into surrounding skin that was never injured, sometimes growing far beyond the original wound site over months or years. This invasive growth into healthy tissue is the defining characteristic of a keloid, not simply its size or firmness.
Keloids also contain a higher proportion of disorganised, thick collagen bundles and show greater vascular activity than hypertrophic scars. Histologically, the two are distinguishable under a microscope, which is one reason a dermatologist's assessment, rather than self-diagnosis, matters before any treatment begins.
Hypertrophic scars can develop in anyone after significant skin trauma, particularly burns, surgical incisions, or wounds that became infected or took a long time to close. They often improve on their own over one to two years as the collagen gradually remodels.
Keloids have a strong genetic component. They are significantly more common in people with darker skin tones, including South Asian, African, and East Asian populations, and they tend to run in families. Common trigger sites include the earlobes after piercing, the chest and upper back after acne, the shoulders, and the jawline. The deltoid region of the upper arm is a particularly high-risk site, which is clinically relevant when considering vaccinations or any elective procedure in someone with a known keloid history.
Importantly, keloids can develop after minor trauma, a small cut, a scratch, an insect bite, in someone who is predisposed. This is why the history of the wound matters as much as the appearance of the scar.
Hypertrophic scars, because they are confined and tend to regress over time, are often managed conservatively first. Silicone gel sheets or silicone-based topical products applied consistently over several months can flatten and soften them by maintaining hydration at the scar surface and modulating fibroblast activity. Pressure garments serve a similar purpose for larger areas, particularly after burns. Intralesional corticosteroid injections, administered by a dermatologist at intervals, can accelerate flattening by suppressing collagen synthesis within the scar.
Keloids are more resistant and more likely to recur after any intervention. Surgical excision alone has a recurrence rate that is high enough that most dermatologists do not recommend it as a standalone treatment. When surgery is considered, it is typically combined with another modality, intralesional corticosteroids, radiation therapy delivered to the site shortly after excision, or both, to reduce the chance of the keloid returning, often larger than before.
Intralesional corticosteroid injections are also used for keloids, but the response is less predictable than in hypertrophic scars, and multiple sessions are usually required. Intralesional 5-fluorouracil, an antimetabolite that interferes with fibroblast proliferation, is used in some cases, sometimes in combination with corticosteroids. Laser treatments, particularly pulsed dye laser, can reduce redness and improve texture, though they address the appearance rather than the underlying growth behaviour.
The key clinical principle is this: any intervention that injures the skin carries a risk of triggering a new or enlarged keloid in a predisposed individual. This includes surgical excision, laser resurfacing, and even needling procedures. A dermatologist assessing a keloid must weigh the benefit of treatment against the real possibility that the treatment itself becomes a new stimulus for growth.
Neither keloids nor hypertrophic scars disappear entirely with treatment. The goal is reduction, in height, firmness, colour, and symptoms such as itching or tenderness, not complete removal. Hypertrophic scars generally respond better and more predictably. Keloids can be significantly reduced in size and made less symptomatic, but the predisposition to form them does not go away, and the risk of recurrence after any treatment remains.
For someone with a known keloid tendency, the most effective strategy is prevention: informing any clinician before elective procedures, avoiding unnecessary piercings or tattoos in high-risk sites, and treating any skin wound carefully to minimise healing time. Once a keloid has formed, management is a long-term process rather than a single-session fix.
Both conditions require clinical diagnosis before treatment begins. Attempting to treat a keloid as if it were a hypertrophic scar, or vice versa, can delay effective management and, in the case of keloids, risk making the scar worse. A dermatologist can distinguish the two on clinical examination, sometimes supported by the wound history and, where necessary, a skin biopsy.
Discover expert advice and the latest updates in Skin Care, Hair Care, Wellness, Dermatology, and more at Stay Young guide to lasting beauty and holistic health!
What Is Actually Happening in the Tissue
The difference lies in where the excess collagen goes. A hypertrophic scar stays within the original wound boundary. It may be raised, firm, and pink, but it does not spread beyond the edges of the initial injury. A keloid does not respect that boundary. It extends into surrounding skin that was never injured, sometimes growing far beyond the original wound site over months or years. This invasive growth into healthy tissue is the defining characteristic of a keloid, not simply its size or firmness.
Keloids also contain a higher proportion of disorganised, thick collagen bundles and show greater vascular activity than hypertrophic scars. Histologically, the two are distinguishable under a microscope, which is one reason a dermatologist's assessment, rather than self-diagnosis, matters before any treatment begins.
Who Gets Them and Where
Keloids have a strong genetic component. They are significantly more common in people with darker skin tones, including South Asian, African, and East Asian populations, and they tend to run in families. Common trigger sites include the earlobes after piercing, the chest and upper back after acne, the shoulders, and the jawline. The deltoid region of the upper arm is a particularly high-risk site, which is clinically relevant when considering vaccinations or any elective procedure in someone with a known keloid history.
Importantly, keloids can develop after minor trauma, a small cut, a scratch, an insect bite, in someone who is predisposed. This is why the history of the wound matters as much as the appearance of the scar.
Why They Are Managed Differently
Keloids are more resistant and more likely to recur after any intervention. Surgical excision alone has a recurrence rate that is high enough that most dermatologists do not recommend it as a standalone treatment. When surgery is considered, it is typically combined with another modality, intralesional corticosteroids, radiation therapy delivered to the site shortly after excision, or both, to reduce the chance of the keloid returning, often larger than before.
Intralesional corticosteroid injections are also used for keloids, but the response is less predictable than in hypertrophic scars, and multiple sessions are usually required. Intralesional 5-fluorouracil, an antimetabolite that interferes with fibroblast proliferation, is used in some cases, sometimes in combination with corticosteroids. Laser treatments, particularly pulsed dye laser, can reduce redness and improve texture, though they address the appearance rather than the underlying growth behaviour.
The key clinical principle is this: any intervention that injures the skin carries a risk of triggering a new or enlarged keloid in a predisposed individual. This includes surgical excision, laser resurfacing, and even needling procedures. A dermatologist assessing a keloid must weigh the benefit of treatment against the real possibility that the treatment itself becomes a new stimulus for growth.
What Cannot Be Fixed and What Can
For someone with a known keloid tendency, the most effective strategy is prevention: informing any clinician before elective procedures, avoiding unnecessary piercings or tattoos in high-risk sites, and treating any skin wound carefully to minimise healing time. Once a keloid has formed, management is a long-term process rather than a single-session fix.
Both conditions require clinical diagnosis before treatment begins. Attempting to treat a keloid as if it were a hypertrophic scar, or vice versa, can delay effective management and, in the case of keloids, risk making the scar worse. A dermatologist can distinguish the two on clinical examination, sometimes supported by the wound history and, where necessary, a skin biopsy.
Discover expert advice and the latest updates in Skin Care, Hair Care, Wellness, Dermatology, and more at Stay Young guide to lasting beauty and holistic health!