Over 80% of people who experience acne develop some form of scarring. The vast majority — 80–90% — are atrophic scars: depressions in the skin where collagen was lost during the inflammatory process. These scars are broken down into icepick (60–70% of atrophic scars), boxcar (20–30%), and rolling (15–25%) types. Each type responds differently to different treatments, and the treatment selection matters more in Fitzpatrick IV–VI skin because the wrong choice can produce post-inflammatory hyperpigmentation that is more visible and longer-lasting than the original scars.
This article covers what the evidence says about treating acne scars in skin of color: which modalities carry the lowest and highest PIH risk, how to match treatment to scar type, and what the realistic outcomes and tradeoffs look like.
The fundamental tension: efficacy vs. pigment risk
Acne scar treatments work by injuring the skin in a controlled way to trigger collagen remodeling. The more aggressive the injury — deeper ablation, higher energy, more thermal damage — the more collagen stimulation, but also the more inflammation.
In Fitzpatrick IV–VI skin, inflammation triggers melanocyte activation. The same inflammatory cascade that drives neocollagenesis also drives post-inflammatory hyperpigmentation. This is not a minor side effect: PIH can take months to resolve, may require its own treatment course, and can appear as dark patches that are more cosmetically noticeable than the scars being treated.
The treatment strategy for skin of color is therefore not "which treatment works best for acne scars" but "which treatment produces enough collagen remodeling to improve scars while staying below the PIH threshold for this specific patient's skin type."
A 2025 systematic review and meta-analysis published in PMC (PMC12982687) compared fractional CO2 laser with microneedling radiofrequency for post-acne scarring across randomized controlled trials. The analysis found that both modalities were effective, but the safety profiles diverged significantly in darker skin — with RF microneedling showing a lower incidence of hyperpigmentation.
Treatment options by PIH risk profile
Lowest PIH risk: non-thermal modalities
Subcision. Subcision uses a needle or cannula to sever the fibrous bands beneath rolling scars that tether the skin downward. Once the bands are released, the skin elevates and the depression improves. There is no thermal injury — the mechanism is purely mechanical — which means PIH risk is very low.
Alam et al. reported that 90% of subcision patients showed improvement, with a mean improvement of 51%. An Indian study found 40–80% improvement in rolling scars. Subcision is often combined with biostimulatory fillers (Sculptra) or HA fillers to maintain the elevation achieved by band release. The combination of subcision with Sculptra carries near-zero PIH risk because neither component involves thermal injury.
Subcision is specifically indicated for rolling scars. It does not address icepick or boxcar scars effectively as a standalone treatment.
Standard microneedling (without RF). Microneedling creates controlled micro-injuries in the dermis using fine needles (0.5–2.5 mm depth), triggering collagen and elastin production through the wound healing cascade without thermal injury. Histological analysis shows increased type I, III, and VII collagen, increased epidermal thickness, and greater density and randomized distribution of elastin fibers in the upper dermis.
For skin of color, standard microneedling has a PIH rate of approximately 2–5% — lower than any thermal modality. A systematic review of 1,029 patients across multiple studies found PIH in 6.8% of roller microneedling cases and 6.6% of RF microneedling cases.
Microneedling produces 50–60% improvement in all atrophic scar types but requires 4–6 sessions spaced 4–6 weeks apart. The collagen production continues for months after each session — research from AIIMS (Singh) documented up to a 400% increase in collagen and elastin 6 months post-treatment.
Moderate PIH risk: controlled thermal modalities
RF microneedling (fractional radiofrequency). RF microneedling combines mechanical needle penetration with radiofrequency energy delivered at the needle tips. The RF energy creates electrothermal injury in the dermis — critically, it bypasses melanin entirely because the energy is delivered from within the skin rather than from above. This is why RF microneedling has a lower PIH rate than laser-based treatments in darker skin.
A 2025 systematic review by Niaz et al. in Clinical, Cosmetic and Investigational Dermatology confirmed that RF microneedling is effective for acne scar management, with stronger evidence for mild-to-moderate scars. Chandrashekar et al. (2014) reported 58% moderate improvement, 9% good, and 3% very good improvement in patients with Fitzpatrick III–V skin.
The PIH rate for RF microneedling in darker skin ranges from 6.6% to 15%, depending on settings and skin type. This is higher than standard microneedling but substantially lower than ablative fractional lasers.
Settings for skin of color matter significantly. Dayan et al. recommend starting at 15 kW or lower for Fitzpatrick IV–VI, adding 5 kW gradually, with a maximum of 40 kW over soft tissue and 25 kW over bone. Needle depth can be adjusted from 0.5 mm to 3.5 mm — a wider range than fractional lasers, which typically reach only 0.7 mm — allowing treatment of deeper scar components.
Typical protocol: 3–4 sessions at 4–6 week intervals. Cost per session in the U.S. ranges from $400 to $1,200.
TCA CROSS (chemical reconstruction of skin scars). TCA CROSS involves focal application of high-concentration trichloroacetic acid (65–100%) directly into icepick scars using a toothpick or fine applicator. The acid causes localized coagulative necrosis, and the subsequent healing response produces collagen that elevates the scar floor.
The 2025 Frontiers in Medicine review on advances in acne scar treatment noted that 70% TCA CROSS demonstrates significant improvement across all atrophic scar subtypes, while 100% TCA serves as a cost-effective alternative for icepick scars in dark-skinned patients — though it remains inferior to CO2 laser in absolute efficacy.
PIH risk is approximately one-third of darker-skinned patients, and the pigmentation may persist. TCA CROSS is most appropriate for icepick scars specifically; it is not designed for rolling or boxcar scars.
Sessions: 2–4 (sometimes up to 6) at 4–6 week intervals. Cost: $200–500 per session. Micro-crusts form at each treated site and heal in 7–10 days.
Phenol (88%) has been proposed as an alternative to TCA for CROSS in darker skin. Dalpizzol et al. found comparable efficacy between carbolic acid and TCA, with carbolic acid having a smaller risk of scar widening — a relevant consideration in Fitzpatrick V–VI.
Non-ablative fractional lasers (1540 nm, 1550 nm). Non-ablative fractional lasers create columns of thermal injury in the dermis without removing the epidermis. In skin of color, they carry a moderate PIH risk that is lower than ablative lasers but higher than non-thermal modalities.
Graber et al. (2008) reported a PIH rate of 0.73% overall across 961 treatments with 1550 nm fractional laser — but the rate is higher in darker phototypes specifically, and the mean PIH duration was 7.5 days. Alexis et al. (2016) published an RCT specifically evaluating nonablative 1550 nm fractional laser for acne scarring in Fitzpatrick IV–VI and found it safe and efficacious, with PIH that was self-limited in the majority of cases.
Hu et al. reported only 3% PIH with fractional Er:YAG (2940 nm) in an Asian population — making it one of the safer laser options for darker skin, though the evidence base is smaller than for 1550 nm.
Highest PIH risk: ablative lasers
Fractional CO2 (10,600 nm). Fractional CO2 laser is one of the most effective treatments for deep acne scars in lighter skin. In darker skin, the efficacy is still present but the PIH risk is substantially elevated.
Published PIH rates for fractional CO2 in darker skin vary widely: Chan et al. reported 55.5% PIH at 1 month and 11.1% residual at 6 months in Fitzpatrick III–IV Asian patients. Across studies, PIH rates range from 6.4% to 92.3% in Fitzpatrick IV–V, depending on settings, density, and provider experience. This enormous range reflects how much the outcome depends on technique: conservative settings — lower fluence, lower density (under 20% fractional coverage), fewer passes — reduce PIH but also reduce efficacy.
A 2025 pilot randomized split-face study by Le Qu et al. published in Acta Dermato-Venereologica directly compared non-insulated microneedle fractional RF with ablative fractional CO2 for facial atrophic acne scars. The study provides head-to-head data that is particularly relevant for skin of color treatment decisions.
1450 nm diode laser. The 1450 nm diode laser (Smoothbeam) has been specifically studied in darker skin for acne scars. Semchyshyn et al. (2013) reported PIH in 56% (10/18) of Fitzpatrick IV–VI patients. Other studies report PIH rates of 30–66.7%. While 83% of patients showed clear improvement maintained over 1 year, the PIH rate makes this a difficult first-line recommendation for dark skin when alternatives exist.
A framework for matching treatment to scar type in skin of color
No single treatment addresses all scar types optimally. The evidence supports matching the modality to the scar morphology:
| Scar type | First-line for skin of color | PIH risk | Sessions | Notes |
|---|---|---|---|---|
| Icepick | TCA CROSS (65–100%) | ~33% | 2–4 | Cost-effective; may combine with microneedling |
| Rolling | Subcision + filler/biostimulator | Near zero | 1–3 | Address fibrous bands mechanically |
| Boxcar | RF microneedling or non-ablative fractional laser | 3–15% | 3–6 | Conservative settings for darker types |
| Mixed atrophic | Combination approach | Varies | Varies | Address each scar type individually |
Combination therapy consistently outperforms monotherapy. A 2025 review in Frontiers in Medicine emphasized that dual approaches — combining microneedling with TCA, glycolic acid, or focused CO2 laser energy — show superior outcomes. The combination of subcision + TCA CROSS + microneedling is particularly effective for mixed scarring in skin of color because it addresses different scar types with the lowest-risk modality for each.
Rullan, Olson, and Lee (2020) published a study in the Journal of Clinical and Aesthetic Dermatology on a combination approach to treating acne scars in all skin types. Of 139 patients, 64% were Fitzpatrick IV–VI. The combination protocol produced results across all skin types, reinforcing that an appropriately sequenced multi-modality approach can work in skin of color when the components are selected for safety.
Pre-treatment preparation
Reducing PIH risk begins before the procedure:
- Hydroquinone 4% applied for 2–4 weeks before treatment to suppress melanocyte activity.
- Tretinoin to promote uniform healing — stopped 1 week before the procedure to prevent overpenetration.
- Broad-spectrum sunscreen SPF 30–50+, started at least 1 month before and continued daily throughout the treatment series.
For patients with a history of PIH, pre-treatment with a combination of hydroquinone and a topical corticosteroid for 4 weeks is a reasonable additional precaution.
A broader PIH management toolkit is available for patients who develop pigmentation after treatment. Azelaic acid 10–20%, tranexamic acid (topical or oral), kojic acid, and alpha arbutin all have evidence for PIH management and can be used as alternatives or adjuncts to hydroquinone. A 2025 study by Hang and Lim in the Journal of Cosmetic Dermatology (PMC12309148) demonstrated that a specific pre- and post-treatment peel system combining azelaic acid, tranexamic acid, and niacinamide significantly reduced PIH scores after fractional CO2 laser (p=0.015).
Keloid and hypertrophic scar risk
Skin of color carries a higher baseline risk of keloid and hypertrophic scarring, which is relevant to both the acne scars being treated and the treatments themselves. People of African, Afro-Caribbean, South Asian, and Hispanic descent are statistically more prone to keloid formation. Any treatment that causes significant dermal injury — including deep fractional laser and aggressive TCA CROSS — has the potential to trigger keloid formation in susceptible individuals. A history of keloid or hypertrophic scarring should be assessed before treatment, and deeply ablative approaches should be used cautiously or avoided in patients with a known keloid tendency. Non-thermal modalities (subcision, standard microneedling at conservative depths) carry lower keloid risk.
Emerging approaches
755 nm picosecond laser with diffractive lens array. A 2025 study published in Dermatologic Surgery (PMID: 39250814) evaluated the 755 nm picosecond laser with a diffractive lens array for acne scars specifically in Fitzpatrick V and VI patients. The study found 100% clinical improvement with no serious adverse events — a notably safe profile for the darkest skin types. The picosecond pulse duration and the diffractive lens delivery create a photoacoustic effect with less thermal damage than traditional fractional lasers.
Nitrogen plasma resurfacing (NeoGen PSR). FDA-cleared for acne scars, nitrogen plasma energy creates controlled thermal injury without chromophore dependence. A "wet technique" has been reported for use in Fitzpatrick V–VI, though this application is off-label and the evidence is still limited.
Combination RF microneedling with topical drug delivery. Using RF microneedling to create channels for topical tranexamic acid, vitamin C, or growth factor delivery is gaining evidence. The RF component addresses scar depth while the topical agent addresses pigment — a relevant combination for patients whose scars are accompanied by post-inflammatory hyperpigmentation.
Questions to ask before starting acne scar treatment in skin of color
- What scar types do I have, and will each type be treated differently? A treatment plan that uses one approach for all scars is suboptimal.
- What is the PIH risk for each proposed treatment at my Fitzpatrick type? The provider should be able to cite specific rates.
- Will pre-treatment with hydroquinone be used? For Fitzpatrick IV–VI, pre-treatment is standard practice.
- What is the sequence — which treatment first, and why? A logical sequence treats the highest-risk (deepest) components first.
- How many sessions are expected, and what does "improvement" look like? Realistic expectations: 50–75% improvement is a good outcome for most atrophic scars.
- What happens if PIH develops? The plan should include immediate intervention (topical hydroquinone, corticosteroid) and a protocol for adjusting subsequent treatments.
Sources
- Fractional CO2 Laser Versus Microneedling Radiofrequency for Post Acne Scarring: A Meta-Analysis of RCTs. PMC, 2025. https://pmc.ncbi.nlm.nih.gov/articles/PMC12982687/
- Advances in the Treatment of Acne Scars. Frontiers in Medicine, 2025. https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2025.1643035/full
- Noninvasive Cosmetic Treatments for Fitzpatrick IV–VI: A Narrative Review. PRS Global Open, 2026. PMC: https://pmc.ncbi.nlm.nih.gov/articles/PMC13012588/
- Niaz G, et al. Fractional Radiofrequency Microneedling as a Monotherapy in Acne Scar Management: A Systematic Review. Clin Cosmet Investig Dermatol, 2025;18:19–29.
- Alexis AF, et al. Nonablative Fractional Laser Resurfacing for Acne Scarring in Fitzpatrick IV–VI. Dermatol Surg, 2016;42:392–402.
- Rullan PP, Olson R, Lee KC. A Combination Approach to Treating Acne Scars in All Skin Types. J Clin Aesthet Dermatol, 2020;13(5):19–23.
- Semchyshyn N, et al. Treating Acne Scars in Fitzpatrick IV–VI Using the 1450-nm Diode Laser. Cutis, 2013;92:49–53.
- Graber EM, et al. Side Effects and Complications of Fractional Laser Photothermolysis: Experience With 961 Treatments. Dermatol Surg, 2008;34:301–305.
- 755-nm Picosecond Laser With Diffractive Lens Array for Acne Scars in Fitzpatrick V and VI. Dermatol Surg, 2025. PMID: 39250814.
- Le Q, Sha S, et al. Comparison of Non-insulated Microneedle Fractional RF and Ablative Fractional CO2 for Atrophic Acne Scarring. Acta Dermato-Venereologica, 2025;105:43611.
