Laser Treatments for Acne Scarring: A Guide By Dr. David Jack

AUTHOR- DR. DAVID JACK

Acne scars -particularly the deep, pitted or fibrotic types - can be among the most persistent and emotionally challenging skin concerns. Unlike active acne, which can often be cleared with medical or topical treatments, scarring represents a structural change in the dermis, requiring intervention at a much deeper level.

Lasers have become a cornerstone of effective acne scar treatment, offering the ability to precisely remodel collagen and resurface uneven skin texture with unparalleled outcomes. However, not all laser technologies are equal and results depend heavily on the type of scarring, skin tone, device settings and the expertise and experience of the practitioner performing the treatment.

 In this article, we’ll break down how laser treatments work to improve acne scarring, explore the leading devices - including fractional CO₂, Erbium:YAG and other fractional lasers for acne scarring - and explain how to build a treatment plan for acne scars that delivers visible, lasting results.

Understanding Acne Scars: Why Texture Requires Restructuring

Acne scarring results from a disrupted wound healing process following inflammation in the pilosebaceous unit. When inflammation is deep or prolonged (as with cystic or nodulocystic acne) it destroys normal collagen and elastin fibres, replacing them with disorganised, fibrotic tissue. Indeed, in healthy, uninjured skin, Type I and Type III collagen are produced in a balanced ratio, providing tensile strength, elasticity and a smooth dermal structure. However, in acne scars, particularly atrophic scars, the balance shifts dramatically. Due to chronic inflammation and impaired wound healing, scar tissue is often composed predominantly of disorganised Type I collagen, with reduced levels of the more elastic Type III. This altered matrix lacks the uniform alignment and elasticity of normal dermis, resulting in a depressed, fibrotic appearance typical of acne scars.

There are several morphological types of acne scars:

• Atrophic scars: The most common type. These include:

◦ Ice pick scars: Narrow, deep, V-shaped indentations

◦ Boxcar scars: Broad, sharply defined edges

◦ Rolling scars: Soft, undulating depressions due to tethering of dermal layers 

• Hypertrophic scars and keloids: Raised, firm tissue overgrowth—more common in darker skin tones

• Post-inflammatory erythema and hyperpigmentation (PIE/PIH): While technically not scars, these can linger long after breakouts resolve and often coexist with textural issues.

Laser treatments aim to remodel this aberrant collagen by triggering a controlled wound-healing response, by damaging or heating the derms, prompting the skin’s fibroblast cells to regenerate healthier, more structured, uniform collagen similar to that found in undamaged tissue.

How Lasers Treat Acne Scarring: Mechanisms of Action

Laser devices used for acne scarring fall into three categories:

• Ablative fractional lasers (e.g. CO₂, Erbium:YAG): Vaporise microscopic columns of tissue, removing damaged skin and stimulating collagen in deeper layers.

• Non-ablative fractional lasers (e.g. 1540nm erbium glass laser): Deliver heat to the dermis without breaking the skin barrier, promoting remodelling with minimal downtime.

• Hybrid technologies (e.g. UltraClear, HALO): Combine ablation and coagulation in controlled proportions for maximum efficacy with lower risk.

These devices rely on fractional photothermolysis, a technique that creates microthermal zones (MTZs) surrounded by healthy skin. This allows faster healing while targeting deep dermal architecture. Over a series of treatments, collagen is synthesised and remodelled, improving skin thickness, tone and elasticity.

Importantly, lasers don’t just smooth scars - they also reduce vascularity in red scars, lighten post-inflammatory pigmentation and improve overall skin texture.

Best Laser Treatments for Acne Scarring: Device-by-Device

1. Fractional CO₂ Laser (10,600 nm) 

Often considered the gold standard for moderate to severe atrophic scarring, fractional CO₂ lasers (e.g. Lumenis UltraPulse, DEKA SmartXide) deliver intense thermal energy deep into the dermis while ablating the epidermis. 

This makes them particularly effective for:

• Ice pick and boxcar scars

• Thickened or photodamaged skin

• Patients seeking dramatic improvement over a single course

Pros:

• Profound collagen stimulation and resurfacing

• One of the few lasers capable of treating deep, pitted scars

• Long-lasting results after 1–3 sessions

Cons:

• Significant downtime (10-14 days of redness, oozing, and crusting)

• Not suitable for darker skin types due to high risk of PIH

• Requires meticulous aftercare to prevent complications

Best for: Fair to medium skin tones with deep or complex scarring; patients willing to tolerate downtime for maximal results. 

2. Erbium: YAG Laser (2,940 nm) 

This laser has a higher absorption coefficient in water than CO₂, meaning it can ablate tissue with more precision and less residual heat. Erbium lasers such as the Sciton Joule (ProFractional or Contour TRL) can be finely tuned for variable depth.

Pros:

• Lower thermal damage, reducing risk of PIH and prolonged erythema

• Faster healing time (4–6 days)

• Safe for Fitzpatrick III–IV with conservative settings

Cons:

• Less dramatic per session compared to CO₂

• Requires multiple sessions for significant scarring

Best for: Mild to moderate atrophic scars, especially in skin of colour or sensitive skin types.

3. UltraClear Laser (2,910 nm cold fibre fractional laser)

A newer entrant in the fractional laser space, UltraClear uses “cold” fibre-optic energy delivery to ablate skin with minimal surrounding thermal injury. This significantly reduces downtime while still stimulating robust collagen renewal. UltraClear uses ultrashort pulses to precisely target damaged skin while preserving epidermal integrity.

Pros:

• Minimal downtime (1–3 days of redness)

• Suitable for a broad range of skin types, including Fitzpatrick IV–V

• Can target pigmentation and textural irregularity simultaneously

Cons:

• Results are cumulative—generally 3–4 sessions needed

• Limited data compared to legacy systems like CO₂

Best for: Patients with mixed pigmentation and textural scarring seeking effective results with minimal social downtime.

4. Alternative and combination Treatments to optimise Laser Resurfacing

While laser resurfacing is often the gold standard for acne scar revision, several non-laser modalities offer valuable alternatives, especially for patients who are not good candidates for ablative procedures due to skin tone, medical history or personal preference.

A tailored approach may include:

• Subcision for rolling scars tethered to underlying tissue

• Chemical peels (such as TCA CROSS for ice pick scars or medium-depth peels like Jessner’s) can improve superficial texture and pigment.

• Microneedling with radiofrequency (e.g. Morpheus8 Resurfacing) for deeper collagen stimulation with minimal surface disruption

• Injectable polynucleotides or exosomes ] post-laser for regenerative support and enhanced healing

• Topical pigment suppressors (azelaic acid, tranexamic acid) in cases of co-existing PIH

Post-Treatment Considerations for Acne Scar Laser

Proper aftercare is crucial in achieving safe and effective results from any laser treatment:

• Strict sun protection for a minimum of 4–6 weeks post-treatment is essential to prevent PIH.

• Avoid harsh actives (retinoids, acids) for 7–10 days post-procedure.

• Use barrier-repair moisturisers rich in ceramides, panthenol, or hyaluronic acid.

• Consider prophylactic antivirals in patients with a history of herpes simplex.

In Fitzpatrick skin types IV–VI, test patches and conservative parameters are advised due to increased risk of pigment alteration. Alternatives like fractional RF microneedling may be preferable in these cases.

How Many Sessions Are Needed?

Results depend on scar depth, type, skin tone, and the laser used.

As a general guide:

• CO₂ or Laser Coring: 1–2 sessions, spaced 3–6 months apart

• Erbium or UltraClear: 3–4 sessions, every 4–6 weeks Visible improvement typically begins 4–6 weeks after treatment and continues for up to 6 months due to ongoing collagen remodelling. 

Laser resurfacing remains one of the most powerful tools in the treatment of acne scarring - but it’s certainly not a case of one-size-fits-all. By choosing the right device, tailoring the depth and density of treatment to the individual and combining with other supportive therapies, we can radically transform the texture, resilience and clarity of acne scarred skin. If you’re living with acne scarring and want to explore a scientifically grounded, medically led approach to treatment, book a consultation.