Laser Treatment

Laser for Keloid Scars: Can You Really Flatten Them?

Q: How many laser sessions are typically needed for keloids?

Most clinical protocols involve 3 to 6 sessions. These are usually spaced 4 to 8 weeks apart to allow the skin to remodel between treatments. Thicker, older keloids may require more sessions or a combination of different laser types.

Keloid scars are notoriously hard to treat, but laser therapy can reduce their size, redness, and firmness. Here's what the evidence shows about using lasers on keloids.

What Laser for Keloid Scars Actually Does — and What to Expect

Laser for keloid scars is a medical treatment that uses focused light energy to reduce the size, redness, and firmness of keloid tissue. Here is a quick overview of what the evidence shows:

Question	Short Answer
Does it work?	Evidence suggests it can help — but certainty is low based on current research
Best-studied laser type	Pulsed-dye laser (PDL, 585–595 nm)
Typical sessions needed	A course of sessions, not one — spacing is device-dependent (2–4 weeks for Nd:YAG)
Permanent cure?	No — recurrence is common without combination therapy
Who benefits most?	Smaller, less inflamed keloids in low-tension skin areas
Main risks	Skin discoloration, purpura, blistering — especially in darker skin tones

Keloid scars form when the skin's wound-healing process goes into overdrive. Instead of producing just enough collagen to repair damaged tissue, the body keeps producing it — long after the wound has closed. The result is a raised, firm, often itchy or painful growth that extends beyond the original wound boundary.

This is not simply a cosmetic quirk. Keloids are classified as fibroproliferative disorders — meaning they involve a pathological overgrowth of fibrous tissue driven by dysregulated cell activity. They can develop after something as minor as a piercing or an acne breakout, and they disproportionately affect people with darker skin tones.

For many people living with keloids, the psychological impact is significant. Visible scars on the chest, shoulders, or earlobes can affect confidence and daily social interactions — especially when the scar has resisted previous treatments.

Laser therapy has emerged as one of several medical approaches for managing keloids. It works by targeting the blood vessels and collagen structures within the scar using specific wavelengths of light. However, it is important to be clear: laser treatment is not a guaranteed cure. A Cochrane systematic review of 15 randomised controlled trials (604 participants) found the overall quality of evidence to be low or very low, due to high risk of bias and significant variation between studies.

That said, research does indicate measurable improvements in scar height, redness, and pliability — particularly with the pulsed-dye laser — and laser is increasingly used as part of a broader, multimodal treatment strategy.

This guide explains how laser therapy works for keloid scars, what types are used, what the clinical evidence actually shows, and what realistic expectations look like.

This content is for informational purposes only and does not constitute medical advice. Consult a qualified healthcare professional for diagnosis and treatment.

Basic laser for keloid scars terms:

Why keloids form and who's at risk

To understand why laser for keloid scars is used, one must first look at the biology of the scar itself. Keloids are the result of an "aberrant" healing process. In a typical wound, cells called fibroblasts produce collagen to bridge a gap in the skin. Once the wound is closed, the body enters a remodeling phase where excess collagen is broken down.

In a keloid, this "off switch" is missing. Myofibroblasts, a specialized type of cell, remain active for much longer than necessary. They pump out thick bundles of hyalinized collagen into the extracellular matrix, creating a dense, rubbery mass. This process is often fueled by chronic inflammation and high skin tension.

Cross-section of skin showing dense collagen fiber bundles in keloid tissue - laser for keloid scars

Prevalence and Demographic Risk

While anyone can develop a keloid, certain populations are at a significantly higher risk. Clinical data shows a strong correlation between skin pigmentation and keloid formation:

People of African descent: Ogawa’s 2022 treatment algorithm reports that 5% to 10% of Africans are affected. Kim (2021) puts the prevalence at about 10% in the African-American population.
Reported prevalence varies widely by country: Kim (2021) cites figures ranging from 0.09% in the United Kingdom to 16% in the Congo.
Asian populations: 0.1% to 1%. European and North American populations: below 0.1% (Ogawa, 2022). Note that hypertrophic scars are a related but different condition and are not counted in these keloid figures.

Genetic predisposition plays a massive role. If a biological parent has a history of keloids, their children are more likely to develop them after minor skin trauma, such as ear piercings or vaccinations.

Distinguishing Keloids from Hypertrophic Scars

It is common to confuse keloids with hypertrophic scars, but the clinical distinction is vital for choosing the right treatment.

Characteristic	Hypertrophic Scar	Keloid Scar
Growth Boundary	Stays within the original wound edges	Spreads beyond the original wound
Regression	Often flattens spontaneously over 1–2 years	Rarely regresses; may grow indefinitely
Timing	Appears within weeks of injury	Can appear months or years later
Common Sites	Any area of injury	Chest, shoulders, earlobes, upper back
Tension	Highly dependent on skin tension	Influenced by tension but can occur anywhere

Scientific research on scar pathophysiology suggests that while both involve excessive collagen, the keloid is a much more aggressive and persistent disorder.

How laser treatment works on keloids

Laser therapy relies on the principle of selective photothermolysis. This means the laser uses a specific wavelength of light to target a "chromophore" (a light-absorbing molecule) without damaging the surrounding healthy skin.

In the context of laser for keloid scars, the primary targets are:

Hemoglobin: Found in the tiny blood vessels (neovascularization) that "feed" the scar.
Water: Found within the scar tissue itself, targeted by ablative lasers to vaporize tissue.

By shutting down the blood supply, the laser starves the myofibroblasts of the nutrients they need to keep producing collagen. This triggers a shift in the tissue remodeling process, often leading to a softer, flatter, and less symptomatic scar.

Efficacy of Pulsed-Dye Laser for Keloid Scars

The Pulsed-Dye Laser (PDL), typically operating at a 585-nm or 595-nm wavelength, is often the first choice for red, itchy keloids. The yellow light is specifically absorbed by the red pigment in blood vessels.

Clinical observations indicate that PDL can significantly reduce erythema (redness) and itching. A Cochrane review found that in two small trials, 585-nm PDL produced scar improvement (scars rated less severe) more often than no treatment — a relative risk (RR) of 1.96, 95% CI 1.11 to 3.45, across 60 scar segments. The reviewers cautioned that this is "low-certainty evidence" because of the small number of participants.

Fractional CO2 Laser for Keloid Scars and Remodeling

While PDL targets blood vessels, the fractional CO2 laser is an ablative technology that targets water. It creates thousands of "microscopic treatment zones" (MTZs)—tiny columns of thermal damage—leaving bridges of untouched skin in between.

This "fractional" approach triggers a vigorous healing response that replaces old, stiff collagen with new, more organized fibers. Furthermore, these tiny channels can be used for Laser-Assisted Drug Delivery (LADD). By applying a corticosteroid or 5-FU immediately after the laser, the medication can penetrate deep into the thick keloid tissue, which is often too hard to reach with a standard needle.

Research on fractional laser technology suggests this combination is more effective than either treatment alone.

Long-Pulsed Nd:YAG and Diode Lasers

For thicker, deeper keloids, the 1064 nm Nd:YAG laser is often preferred. Because of its longer wavelength, it penetrates deeper into the reticular dermis than the PDL. It is particularly useful for targeting the deeper vascular networks that sustain larger keloid masses.

A more recent innovation involves the intralesional 1470 nm diode laser. Instead of firing light through the surface of the skin, a thin bare-fibre is inserted directly into the scar tissue. This allows the heat to be delivered precisely where the collagen is densest. Research on Nd:YAG applications and diode lasers has shown promising results in reducing scar volume with fewer surface side effects.

Clinical Evidence and Treatment Outcomes

When considering laser for keloid scars, it is important to look at the hard data. The gold standard for medical evidence is the systematic review.

A major Cochrane review examined 15 randomized controlled trials (RCTs) involving 604 participants. The findings were mixed:

Pulsed-dye laser: May improve scar severity compared to no treatment, but the evidence is low-certainty.
Fractional CO2: It is unclear whether fractional CO2 laser changes keloid or hypertrophic scar severity compared with no treatment — the reviewers graded this as very low-certainty evidence.

The review made no ablative-versus-non-ablative comparison, and its overall conclusion was that there is insufficient evidence to support or refute laser therapy for hypertrophic and keloid scars. The idea that ablative lasers such as CO2 work better on thick keloids is textbook clinical consensus rather than trial evidence — and this article’s own reference on treatment algorithms points the other way. Ogawa’s 2022 update reports that randomized controlled trials of nonablative and ablative fractional CO2 lasers showed no beneficial effects, and that fully ablative laser therapy is not recommended for pathologic scars because of high recurrence — which for a keloid means the scar can return larger than it was.

Clinicians typically measure success using the Vancouver Scar Scale (VSS) or the Patient and Observer Scar Assessment Scale (POSAS), which look at height, vascularity, pliability, and pigmentation. Research on intralesional laser efficacy has demonstrated that while total removal is rare, significant improvements in these metrics are achievable.

Success Rates and Recurrence Risks

The "elephant in the room" with keloid treatment is recurrence. Keloids are notorious for coming back, often larger than before, especially after surgery.

Surgery alone: Recurrence rates range from 45% to 100%.
Laser therapy: Recurrence after laser has not been reliably measured. The Cochrane reviewers flagged that the trials they included did not report recurrence rates at all, and a 2026 network meta-analysis of 51 studies and 3,234 participants found no significant recurrence differences between any of the interventions it compared.

Most dermatologists now use multimodal therapy. This involves combining laser sessions with monthly corticosteroid injections, cryotherapy (freezing), or silicone gel sheets. This multi-pronged attack addresses both the blood supply and the cellular activity of the scar.

That approach matches the most recent professional guidance available. A 2026 Latin American Delphi consensus on energy-based devices for keloids and hypertrophic scars — 22 dermatologists, 23 clinical scenarios, three rounds, agreement reached on 21 of 23 — consistently preferred combination therapy over monotherapy, and set out specific safety recommendations for higher skin phototypes. Notably, it positions fractional lasers primarily as a way to improve texture after the scar has been flattened, rather than as a flattening treatment in their own right.

Potential Side Effects and Safety

Laser treatment is a medical procedure with inherent risks. The most common side effects include:

Purpura: Small purple spots or bruising (common after PDL).
Blistering and Crusting: Occurs if the laser energy is too high.
Pigmentation Changes: Post-inflammatory hyperpigmentation (PIH) or hypopigmentation (lightening of the skin) is a significant concern, particularly for those with darker skin (Fitzpatrick scales IV-VI).

To minimize these risks, many practitioners use cooling systems (like cold air or chilled tips) and perform "test patches" before treating the entire scar.

Practical Guidance for Laser Therapy

If you are considering laser for keloid scars, the process usually begins with a thorough consultation. A board-certified dermatologist will assess the scar's age, location, and "activity" (whether it is still growing or itchy).

Who is a good candidate

Not every keloid is a good candidate for laser.

Ideal candidates: Those with smaller, symptomatic (itchy/painful) scars that have not responded to silicone or basic injections.
Red Flags: In some cases, a doctor may perform a biopsy to rule out malignancy (like dermatofibrosarcoma protuberans), which can mimic a keloid.

Expectations must be managed. Laser therapy is rarely a "one-and-done" solution. Most patients require a series of treatments over several months to see meaningful changes.

Cautions and precautions

There are no absolute bars to laser treatment of keloids, but there are precautions worth raising at consultation. The fractional laser chapter of the Textbook on Scar Management sets out the main ones:

Impaired wound healing: Caution is advised with any underlying process that impedes wound healing.
A history of herpes simplex: Especially where the treatment area is around the mouth, this should prompt prophylactic management — oral antivirals should be considered before treatment.
Depth limits: Current ablative fractional devices penetrate to roughly 4 mm, so deeper keloids are less likely to respond well.
Darker skin phototypes: The risk of post-inflammatory hyperpigmentation is higher at Fitzpatrick IV–VI, which is why conservative settings and a test patch in a non-conspicuous area are standard practice.

Post-Treatment Care and Prevention

What happens after the laser is just as important as the treatment itself. The skin will be sensitive and prone to further scarring if not handled correctly.

Sun Protection: UV exposure can darken the scar permanently. Strict sun avoidance or high-SPF mineral sunscreen is mandatory.
Silicone Therapy: Using silicone gel or sheets between laser sessions helps maintain hydration and provides constant pressure, which can inhibit further collagen growth.
Wound Care: Following the specific cleaning and moisturizing routine provided by the clinic is essential to prevent infection.

Frequently Asked Questions about Laser for Keloid Scars

How many laser sessions are typically needed for keloids?

Laser for keloids is a course of treatment rather than a single procedure. No trial has established an optimal number of sessions, and published protocols vary. Spacing depends on the device: the long-pulsed Nd:YAG chapter of the Textbook on Scar Management specifies intervals of 2 to 4 weeks between sessions. Thicker, older keloids may require more sessions or a combination of different laser types.

Is laser treatment for keloids permanent?

There is no "permanent cure" for the keloid-prone individual. While the laser can flatten and soften an existing scar, the genetic tendency to form keloids remains. Maintenance therapy or prompt treatment of new injuries is often necessary.

Does insurance cover laser scar removal?

This is a gray area. Most insurance providers view scar removal as a cosmetic procedure. However, if the keloid causes functional impairment (limiting movement) or significant physical symptoms (chronic pain and itching), a dermatologist may be able to provide documentation of "medical necessity" for partial coverage.

Conclusion

Managing keloids is a marathon, not a sprint. While laser for keloid scars offers a sophisticated way to target the vascular and structural components of these difficult growths, it is most effective when used as part of a comprehensive plan.

The science of scar healing is constantly evolving. Ongoing research into topical imiquimod, botulinum toxin (Botox), and even stem cell therapy provides hope for even more effective treatments in the future. For now, the combination of laser technology and traditional therapies remains the most evidence-based path toward "taming the bump" and regaining skin confidence.

For more information on the latest in skin regeneration, visit Scar Healing.