The single best treatment for acne scars depends almost entirely on which type of scar you have. Ice pick scars, boxcar scars, rolling scars, raised scars, and the flat discoloration many people call “scars” all respond to different procedures and products. A treatment that works beautifully on one scar type can be close to useless on another. Getting the scar type right is the first and most consequential step, and most faces carry a mix of types, which is why dermatologists increasingly favor combination protocols rather than any single silver-bullet procedure.
How to Tell Your Scar Types Apart
Acne affects roughly 80 percent of people between ages 11 and 30, and many end up with some degree of scarring.1PubMed Central. Acne Scarring-Pathogenesis, Evaluation, and Treatment Options The most common category is atrophic scars, meaning the skin has lost tissue and sits below the surrounding surface. Within that category, there are three distinct shapes:
- Ice pick scars: Narrow, deep, and V-shaped, like someone poked the skin with a thin instrument. They extend into the deeper dermis and are the hardest type to treat with surface-level procedures.
- Boxcar scars: Wider than ice picks with steep, well-defined vertical edges and a flat base, often described as U-shaped. They can be shallow or deep.
- Rolling scars: Broad, shallow depressions with sloping edges that give the skin a wave-like or undulating look. They are caused by bands of scar tissue pulling the surface down from beneath.
On the opposite end, some scars are raised above the skin surface. Hypertrophic scars stay within the borders of the original acne lesion and may flatten on their own over time. Keloids grow beyond the original wound and are especially common on the jawline, chest, and back. Finally, many people use the word “scar” to describe the flat red or brown marks left behind after a pimple heals. These are post-inflammatory erythema (the redness) and post-inflammatory hyperpigmentation (the dark spots). They are technically not scars because the skin’s texture is intact, but they can last months or years and deserve their own treatment strategy.
Ice Pick Scars
Ice pick scars are the most stubborn of the atrophic types. Because they plunge deep and narrow into the skin, broad resurfacing tools struggle to reach the bottom. One study that compared how the three atrophic scar types responded to non-ablative fractional laser found that ice pick scars improved the least, by only about 26 percent, compared to roughly 53 percent for boxcar and 43 percent for rolling scars.2PubMed Central. Which type of atrophic acne scar (ice-pick, boxcar, or rolling) responds to nonablative fractional laser therapy? That gap explains why dermatologists reach for different tools here.
The treatment with the strongest track record for ice pick scars is the TCA CROSS technique, which stands for chemical reconstruction of skin scars. A clinician dips a wooden applicator or toothpick-like tool into high-concentration trichloroacetic acid (typically 90 to 100 percent) and applies it directly into each individual scar. The acid triggers a controlled wound-healing response at the bottom of the pit, and repeated sessions build up new collagen from the inside out. In one study using 100 percent TCA, eight of ten patients showed more than 70 percent improvement, with the remaining two showing 50 to 70 percent improvement.3PubMed Central. An Assessment of the Efficacy and Safety of CROSS Technique with 100% TCA in the Management of Ice Pick Acne Scars A comprehensive review across multiple studies found patient improvement rates in the 50 to 80 percent range with TCA CROSS, and generally high satisfaction.4PubMed Central. The Use of Chemical Reconstruction of Skin Scars (CROSS) Method With Trichloroacetic Acid (TCA) for Atrophic Scars
For the deepest ice pick scars, especially those classified as the most severe grade, resurfacing alone often is not enough. Punch excision, where the scar is literally cut out with a small circular blade and the wound sutured or allowed to heal, remains a practical option. Punch elevation is a variation where the base of the scar is lifted to match the surrounding skin level. These minor surgical approaches are considered when lasers and chemical methods have reached their limits.5PubMed Central. Evidence-based Surgical Management of Post-acne Scarring in Skin of Color The trade-off is a tiny new scar line, but it usually looks far better than a deep pit.
Boxcar Scars
Boxcar scars are the most responsive of the three atrophic types to a wide range of resurfacing tools, which is good news if this is your dominant scar pattern. Their relatively flat base and defined edges mean that building up the floor of the scar with new collagen can dramatically improve how they look.
Fractional lasers are a primary option. Ablative fractional CO2 laser and non-ablative fractional lasers both stimulate collagen remodeling. In one split-face study of 30 patients, both fractional CO2 and a non-ablative 1410-nm diode laser produced significant improvement in scar scores compared to baseline, with no statistically significant difference between the two devices. Both showed increased collagen deposition on biopsy.6Cosmetics. Fractional Ablative Carbon Dioxide Laser versus Fractional Non-Ablative 1410 nm Diode Laser in the Treatment of Acne Scars That finding is helpful because non-ablative lasers involve less downtime and lower complication risk, so they can be a reasonable alternative when aggressive ablative treatment is not practical.
Radiofrequency microneedling has also gained ground for boxcar scars. The device drives insulated needles into the skin and delivers radiofrequency energy at the tip, heating the deep dermis to stimulate collagen without damaging the surface. One study specifically found that boxcar scars responded better than other types to this treatment, with statistically significant improvement.7PubMed. Microneedle fractional radiofrequency for atrophic acne scars The collagen remodeling triggered by radiofrequency microneedling is slow and progressive but continues improving for at least six months after the last session.8Dermatologic Surgery. Radiofrequency Microneedling: A Comprehensive and Critical Review Patience matters here; judging results too early is a common mistake.
Rolling Scars
Rolling scars look different from boxcar and ice pick scars because the problem is not just at the surface. Fibrous bands of scar tissue beneath the skin tether the surface downward, creating that undulating, wave-like terrain. Treating these scars effectively means releasing those tethers.
Subcision is the treatment most directly aimed at this problem. A dermatologist inserts a needle or a blunt cannula under the skin and sweeps it back and forth to physically cut the fibrotic bands anchoring the scar. This allows the skin to lift back up. Published improvement rates after subcision range widely, from about 10 to 100 percent depending on the study and technique used, but the procedure is one of the few that addresses the underlying structural cause of rolling scars rather than just the surface appearance.9PubMed Central. A systematic review of treatments for acne scarring. Part 1: Non-energy-based techniques
One problem with subcision alone is that the bands can re-form as the wound heals. To prevent this, some practitioners combine subcision with injectable fillers that hold the released tissue in its new, elevated position. A pilot study that combined radiofrequency-assisted subcision with polycaprolactone-based dermal fillers found statistically significant reductions in rolling scar counts, with the total number of rolling lesions dropping by an average of about five per patient.10PubMed Central. Radiofrequency-assisted subcision combined with polycaprolactone-based dermal fillers in the management of atrophic facial acne scars The filler acts as a spacer, keeping the skin from sinking back down while new collagen develops.
Subcision also pairs well with microneedling and TCA CROSS. A case series using all three in combination reported consistently high patient satisfaction and photographic evidence of improvement across all skin types. Subcision released the tethers, CROSS stimulated collagen at the base of deeper scars, and microneedling smoothed the overall texture.11PubMed Central. A Combination Approach to Treating Acne Scars in All Skin Types
Hypertrophic and Keloid Scars
Raised scars from acne are less common than atrophic ones but more common than many people realize, particularly on the jawline, chest, upper back, and shoulders. Hypertrophic scars stay within the borders of the original lesion, while keloids spill past them. The treatment approach for both centers on flattening the excess tissue and quieting the overactive wound-healing process that created it.
Steroid injections with triamcinolone acetonide have been the go-to treatment for decades. More recently, clinicians have been combining the steroid with 5-fluorouracil (5-FU), a drug that slows the overgrowth of scar-forming cells. A study comparing the three approaches found that all were effective, but the combination of triamcinolone plus 5-FU offered the fastest response with fewer side effects than either drug alone.12PubMed Central. Comparison of Intralesional Triamcinolone Acetonide, 5-Fluorouracil, and Their Combination in Treatment of Keloids A systematic review covering nearly 500 patients confirmed that 5-FU treatment was effective in 45 to 96 percent of cases, though it cautioned that the evidence base is still not strong enough to declare the combination definitively superior.13Acta Dermato-Venereologica. Intralesional 5-Fluorouracil in Keloid Treatment: A Systematic Review
Silicone gel sheets and topical silicone products are an accessible first step and can be used at home. A meta-analysis of hypertrophic scar treatments in adults found that silicone modalities and laser treatments both significantly improved scar scores, and it supported the use of injected triamcinolone combined with 5-FU or silicone, pulsed dye laser, and fractionated CO2 laser for these scars.14PubMed. Management of hypertrophic scars in adults: A systematic review and meta-analysis That said, one older controlled study found that silicone gel sheeting and pulsed dye laser were not significantly better than the untreated control sections over 40 weeks, with all three sections (including control) showing improvement in redness over time.15Archives of Dermatology. Prospective, Single-blind, Randomized, Controlled Study to Assess the Efficacy of the 585-nm Flashlamp-Pumped Pulsed-Dye Laser and Silicone Gel Sheeting in Hypertrophic Scar Treatment The evidence is mixed enough that many dermatologists still recommend silicone as a low-risk starting point while reserving injections and lasers for scars that do not respond.
Post-Inflammatory Erythema and Hyperpigmentation
Many people seeking treatment for “acne scars” actually have flat discoloration rather than textural scars. This is worth identifying early because the treatments are different, generally less invasive, and sometimes the marks will fade on their own with time. Post-inflammatory erythema (PIE) is the persistent redness that lingers after a pimple, more visible on lighter skin. Post-inflammatory hyperpigmentation (PIH) is the brown or dark patch left behind, more common and more persistent in darker skin tones.
For PIE, vascular-targeting devices work best. Pulsed dye laser targets the dilated blood vessels that give these marks their red color and is considered the reference-point treatment for vascular lesions.16PubMed Central. The Comparable Efficacy Between Tranexamic Acid Intradermal Injection and Pulsed Dye Laser for Treatment of Post-Acne Erythema Intense pulsed light (IPL) is another option. In one study of 33 patients, roughly a third saw excellent improvement and another 45 percent saw good improvement in erythema scores after IPL.17PubMed Central. Intense Pulsed Light Therapy for Acne-induced Post-inflammatory Erythema A larger retrospective study found that about 82 percent of patients showed complete or partial clearance of both erythema and hyperpigmentation after IPL treatment.18PubMed Central. Intense Pulsed Light Therapy Improves Acne-Induced Post-inflammatory Erythema and Hyperpigmentation An interesting emerging option for PIE is intradermal tranexamic acid injections, which reduced redness comparably to pulsed dye laser in a split-face trial, cutting redness by about 18 percent on the tranexamic acid side versus 16 percent on the laser side.16PubMed Central. The Comparable Efficacy Between Tranexamic Acid Intradermal Injection and Pulsed Dye Laser for Treatment of Post-Acne Erythema
For PIH, topical agents are the foundation. Azelaic acid is one of the better-studied options. A trial of 15 percent azelaic acid gel found a significant decrease in melanin content in PIH lesions after 12 weeks.19PubMed Central. Effects of 15% Azelaic Acid Gel in the Management of Post-Inflammatory Erythema and Post-Inflammatory Hyperpigmentation in Acne Vulgaris Tranexamic acid used topically is another option. A clinical trial comparing 20 percent azelaic acid cream with 5 percent tranexamic acid solution found both improved hyperpigmentation scores over the study period, with no significant difference between the two.20PubMed Central. A comparative study of 20% azelaic acid cream versus 5% tranexamic acid solution for the treatment of postinflammatory hyperpigmentation in patients with acne vulgaris Other well-known options include retinoids, vitamin C serums, niacinamide, and hydroquinone (though prolonged hydroquinone use requires medical supervision). Sunscreen is non-negotiable during treatment for PIH because UV exposure can darken the spots and undo progress.
Treatment Considerations for Darker Skin Tones
If you have medium to deep skin, the treatment calculus shifts. Many laser-based and energy-based treatments carry a higher risk of triggering new post-inflammatory hyperpigmentation in darker skin, which would defeat the purpose. Fractional CO2 laser can still be used, but the parameters must be adjusted: lower fluence, lower density, and a preference for longer pulse modes to protect the epidermis. Some clinicians also perform a priming phase with chemical peels and laser toning before the ablative procedure to reduce baseline pigment and minimize complications.21PubMed Central. Fractional Carbon Dioxide Laser: Optimizing Treatment Outcomes for Pigmented Atrophic Acne Scars in Skin of Color
Procedures that work below the skin surface without heating the epidermis tend to be safer across all skin tones. Subcision, TCA CROSS (when applied carefully), and microneedling all carry lower risks of pigmentary complications because they either bypass the surface layer entirely or limit damage to tiny, controlled columns. The combination protocol of CROSS plus subcision plus microneedling was specifically studied across all skin types and produced high satisfaction regardless of skin tone.11PubMed Central. A Combination Approach to Treating Acne Scars in All Skin Types Radiofrequency microneedling is another option favored in darker skin because its insulated needles deliver energy beneath the surface rather than through it.
Why Combination Approaches Usually Win
Most real-world acne scarring is a mix of scar types scattered across the face. Even if one type dominates, you will likely have at least some of the others. This is a major reason why combining procedures, often across multiple sessions, tends to outperform any single treatment used alone. A review of the literature on acne scar treatment noted that while many individual treatments have evidence behind them, there is surprisingly little formal study of how to combine them safely and effectively.22Dermatologic Surgery. Acne Scar Treatment: A Multimodality Approach Tailored to Scar Type That gap between what clinicians actually do (combine treatments routinely) and what has been formally studied is worth keeping in mind.
One study that did evaluate a structured combination approach used subcision, TCA CROSS, and fractional CO2 laser together on patients with varying severity. Among those with the most severe scars (grade 4), nearly two-thirds improved by two full grades, and all patients with moderate (grade 2) scars were left with no visible scarring.23PubMed Central. Combination therapy in the management of atrophic acne scars Those results are better than what any single procedure typically delivers on severe scarring. The logic is straightforward: subcision handles the tethering under rolling scars, CROSS fills in the deep narrow pits of ice pick scars, and laser resurfaces the broader boxcar depressions and overall texture. Each tool addresses a different structural problem.
What Topicals Can and Cannot Do
Over-the-counter and prescription topicals are the most accessible option, but they have real limits. For established, deeper scars with actual tissue loss, no cream or serum will fill in the missing collagen. However, topicals have a role in two situations: improving very mild, shallow scarring and maintaining results after procedural treatments.
Tretinoin (prescription retinoid) has been shown to increase collagen synthesis in the skin and help remodel the epidermis, which can modestly improve the appearance of shallow scars over time.24PubMed Central. Retinoic acid and glycolic acid combination in the treatment of acne scars Glycolic acid peels, whether done at home in lower concentrations or in-office at higher ones, promote exfoliation and increase collagen and mucopolysaccharide production in the dermis.25PubMed Central. A comparative study of 70% glycolic acid and 30% trichloroacetic acid peel in the treatment of facial atrophic acne scars The combination of a retinoid with regular glycolic acid use is a reasonable low-cost starting point for mild scarring or as a maintenance strategy.
The honest framing is this: topicals work on texture and skin quality, not on filling craters. If your scars are deep enough to cast a shadow, you are going to need an in-office procedure. Topicals can help optimize your skin before and after those procedures, and they are the right tool for post-inflammatory hyperpigmentation, but expecting them to replace subcision or laser work for moderate-to-severe scarring will lead to frustration.
The Emotional Weight of Acne Scars
Acne scars carry a psychological burden that is often underestimated by people who do not have them. A multi-country survey of patients with facial atrophic acne scars found that three-quarters were self-conscious about their scarring, nearly half reported it negatively affected their social activities, and about 42 percent said it hurt their work performance. More than a fifth had quality-of-life scores indicating a “very large” or “extremely large” impact.26PubMed Central. Impact of Facial Atrophic Acne Scars on Quality of Life: A Multi-country Population-Based Survey The severity of this impact correlated with self-rated scar severity, with about a third of those with severe or very severe scars reporting the highest level of impairment.
Despite these numbers, the tools clinicians use to measure treatment success tend to focus on clinical scar grading rather than how the patient actually feels about the outcome. A review of patient-reported outcome instruments found that out of 54 surveys used in acne research, only two had adequate measurement properties, and only one of those, the ACNE-Q, specifically addressed the impact of post-acne scarring.27PubMed Central. Beyond the Surface: A Deeper Look at the Psychosocial Impacts of Acne Scarring This gap matters because a treatment that improves a scar by one clinical grade but does not change how a person feels about their face may not be delivering meaningful benefit. If you are considering treatment, it is worth being clear with your provider about your goals, not just in clinical terms but in terms of what would actually change your daily experience.
Emerging Treatments on the Horizon
Regenerative medicine is creeping into acne scar treatment. Platelet-rich plasma (PRP), where your own blood is drawn, concentrated, and reinjected, has been used as an add-on to microneedling and laser treatments for several years. More recently, researchers have begun exploring exosomes derived from fat-tissue stem cells. A split-face trial comparing PRP with these exosomes for skin rejuvenation found that both increased collagen and glycosaminoglycans over six months, with no statistically significant difference between the two.28PubMed Central. Adipose Mesenchymal Stem Cell‐Derived Exosomes Versus Platelet‐Rich Plasma Treatment for Photoaged Facial Skin That study focused on photoaged skin rather than acne scars specifically, but the collagen-boosting mechanism is why practitioners are interested in applying these tools to scarring.
These biologics are not yet standard-of-care for acne scars, and much of the available evidence consists of small studies or investigations that were designed for broader skin-quality endpoints. PRP has the most clinical track record so far, typically used alongside microneedling to enhance collagen production. Exosome therapies are newer and currently sit in a regulatory gray area in many countries. They are worth knowing about, but not worth choosing over well-established procedures when your scars are severe and you want predictable results.