Treating acne scars effectively depends almost entirely on correctly identifying which type of scar you have, because the treatments that work well for one type can be useless or even counterproductive for another. Atrophic scars (indentations in the skin) break down into ice pick, boxcar, and rolling subtypes, each responding to different procedures. Raised scars like hypertrophic and keloid types require the opposite approach entirely. And the flat red or brown marks many people call “scars” are a separate category with their own treatment logic.
The Three Atrophic Scar Types
Most acne scars are atrophic, meaning they sit below the surface of the surrounding skin. The damage happens when severe inflammation destroys collagen and tissue within the follicle wall, sometimes driven by bacterial enzymes that break down the structural support of the skin.1Burns & Trauma. Acne-induced pathological scars: pathophysiology and current treatments The three subtypes look and behave differently:
- Ice pick scars: Narrow, deep, V-shaped pits that extend into the dermis. They look like the skin has been punctured with a sharp instrument. Their depth and narrow opening make them the hardest atrophic type to treat with surface-level procedures.
- Boxcar scars: Wider depressions with sharply defined vertical edges, almost like a crater. They can be shallow or deep, and the depth matters for choosing treatment.
- Rolling scars: Broad, shallow undulations that give the skin a wave-like texture. They form when fibrous bands of tissue tether the skin’s surface to deeper layers, pulling it downward.2PubMed Central. Can Subcision with the Cannula be an Acceptable Alternative Method in Treatment of Acne Scars?
Most people with acne scarring have a mix of all three types scattered across their face, which is one reason a single treatment rarely gets the job done.
TCA CROSS for Ice Pick and Deep Boxcar Scars
The go-to targeted treatment for ice pick scars is a technique called CROSS, which stands for chemical reconstruction of skin scars. A dermatologist applies a high concentration of trichloroacetic acid (TCA) directly into individual scars using a toothpick or fine applicator. The acid triggers a controlled wound-healing response at the base of each scar, stimulating new collagen that gradually lifts the depressed area closer to the surrounding skin level.
In one study using 100% TCA, more than 70% improvement was seen in eight out of ten patients, with the remaining two still achieving good results in the 50 to 70% improvement range. Side effects were minimal, limited to temporary pigment changes in two patients.3PubMed Central. An Assessment of the Efficacy and Safety of CROSS Technique with 100% TCA in the Management of Ice Pick Acne Scars Both 50% and 80% TCA concentrations have been studied and found safe and effective for this purpose.4Dermatologic Surgery. Comparing the Use of 80% Trichloroacetic Acid and 50% Trichloroacetic Acid for the Treatment of Ice Pick Acne Scars
TCA CROSS also works on boxcar scars. When researchers compared results across scar types using 50% TCA, ice pick and boxcar scars both showed significant improvement after three sessions, but rolling scars did not respond meaningfully to the same treatment.5Egyptian Journal of Dermatology and Venereology. Chemical reconstruction of skin scars (CROSS) technique using trichloroacetic acid 50% in different types of atrophic acne scars This is a consistent finding across the literature: TCA CROSS is well suited for narrow, well-defined scars but does little for the broad, shallow depressions of rolling scars. The treatment typically requires multiple sessions spaced weeks apart, with each round building on the collagen produced by the last.
Punch Techniques for Deep Scars
For scars that are too deep or too wide for chemical reconstruction alone, minor surgical procedures called punch techniques remain the gold standard. These use a small circular blade, similar to a biopsy punch, to physically remove or reshape individual scars.6PubMed Central. Efficacy of Punch Elevation Combined with Fractional Carbon Dioxide Laser Resurfacing in Facial Atrophic Acne Scarring
In punch excision, the entire scar is cut out and the wound is closed with a tiny suture or allowed to heal on its own, leaving a much smaller, flatter mark in place of the original pit. Punch elevation takes a different approach: instead of removing the whole scar, only the depressed base is freed and lifted to the level of the surrounding skin, while the scar’s walls are left intact. This reduces the risk of color mismatch or additional scarring at the treatment site. Punch elevation is especially useful for deep boxcar scars with sharp edges and a normal-looking base. Both techniques are often followed by a resurfacing procedure like a fractional laser to blend the treated areas into the surrounding skin.
Subcision for Rolling Scars
Rolling scars require a fundamentally different approach because their problem is not missing tissue at the surface but fibrous tethering underneath. Subcision addresses this directly. A needle or small cannula is inserted beneath the scar to physically break the fibrous bands pulling the skin down. Once those bands are severed, the skin releases upward, and the pocket of space created underneath fills with blood that eventually reorganizes into new connective tissue.2PubMed Central. Can Subcision with the Cannula be an Acceptable Alternative Method in Treatment of Acne Scars?
Subcision alone produces visible improvement in rolling scars, but studies consistently show better outcomes when it is combined with other modalities. In a trial comparing subcision alone against subcision plus fractional CO2 laser or subcision plus hyaluronic acid filler, both combination groups outperformed subcision by itself, and the percentage of patients achieving excellent improvement was significantly higher in the combination arms.7PubMed Central. A combined subcision approach with either fractional CO2 laser (10,600 nm) or cross-linked hyaluronic acid versus subcision alone in atrophic post-acne scar treatment The logic is straightforward: subcision releases the tethering, and the second procedure (laser or filler) rebuilds the volume or texture that was lost.
Fractional Lasers and Radiofrequency Microneedling
These energy-based devices treat broader areas of scarring rather than targeting individual pits. They work across all atrophic scar types, though not equally well for each.
Fractional lasers come in two main categories. Ablative fractional lasers (typically CO2 at 10,600 nm) vaporize tiny columns of skin tissue, triggering a robust wound-healing and collagen-remodeling response. Non-ablative fractional lasers (like erbium glass at 1,540 or 1,550 nm) heat the tissue without removing it, causing less damage and less downtime but requiring more sessions. A split-face study found that the ablative CO2 laser produced slightly higher improvement grades, but the non-ablative side had significantly less crusting (about 2 days versus 7), less redness, and lower pain scores.8PubMed. Non-ablative 1550-nm erbium-glass and ablative 10 600-nm carbon dioxide fractional lasers for acne scars: a randomized split-face study with blinded response evaluation Another comparison found similar patient satisfaction between the two approaches, with roughly a third of patients in each group achieving more than 50% improvement.9PubMed. Acne scars in ethnic skin treated with both non-ablative fractional 1,550 nm and ablative fractional CO2 lasers
Not all scar types respond equally to fractional lasers. One study using a non-ablative fractional laser found boxcar scars improved by about 53%, rolling scars by about 43%, and ice pick scars by only about 26%.10PubMed Central. Which type of atrophic acne scar (ice-pick, boxcar, or rolling) responds to nonablative fractional laser therapy? The deep, narrow channels of ice pick scars simply do not respond as well to treatments that resurface the skin from the top down.
Radiofrequency microneedling combines the collagen-stimulating punctures of microneedling with heat energy delivered through the needle tips. A real-world study of 126 patients found that about 73% achieved moderate to significant improvement, and results kept getting better with additional sessions.11PubMed. Efficacy and safety of fractional microneedle radiofrequency for atrophic acne scars: A real-world clinical study of 126 patients Another study confirmed rolling and boxcar scars responded better to radiofrequency microneedling than ice pick scars did.12PubMed Central. Efficacy and safety of microneedling radiofrequency in acne scars The technology is considered safe for all skin tones, which matters because some laser treatments carry higher risks for people with darker skin.13PubMed Central. The Role of Fractional Radiofrequency in Long-term Acne Remission and Reduction of Acne Scar Load
Raised Scars Need the Opposite Strategy
Hypertrophic scars and keloids are the mirror image of atrophic scars: instead of losing tissue, the skin overproduces collagen, creating raised, firm bumps at the site of old breakouts. Hypertrophic scars stay within the original wound boundary and sometimes flatten on their own over months or years. Keloids extend beyond the original wound and almost never resolve without treatment.
A systematic review and meta-analysis of treatments for hypertrophic scars in adults found that silicone gel or sheets, injected triamcinolone (a steroid), pulsed dye laser, and fractional CO2 laser all had supporting evidence. Combining injected triamcinolone with either silicone products or 5-fluorouracil worked better than steroid injections alone.14PubMed. Management of hypertrophic scars in adults: A systematic review and meta-analysis If you have raised acne scars, the worst thing you could do is pursue the aggressive resurfacing treatments designed for atrophic scars, as they could worsen the excess collagen production.
Red and Dark Marks That Are Not True Scars
Many people looking up “acne scar treatment” actually have post-inflammatory erythema (persistent red or pink marks) or post-inflammatory hyperpigmentation (brown or dark spots) rather than true textural scarring. These marks are flat, meaning the skin surface is smooth, but the discoloration can last months or even years after a breakout heals.
Post-inflammatory erythema responds well to light-based treatments. Intense pulsed light (IPL) therapy significantly reduced redness scores in one study, with about a third of patients seeing excellent improvement and another 45% seeing good improvement.15PubMed Central. Intense Pulsed Light Therapy for Acne-induced Post-inflammatory Erythema A larger retrospective study of 60 patients found that over 80% achieved complete or partial clearance of both redness and dark spots after IPL treatment.16PubMed Central. Intense Pulsed Light Therapy Improves Acne-Induced Post-inflammatory Erythema and Hyperpigmentation: A Retrospective Study in Chinese Patients Pulsed dye lasers, which target blood vessels specifically, have also shown good results for post-inflammatory erythema.17PubMed Central. Easy as PIE (Postinflammatory Erythema)
Post-inflammatory hyperpigmentation is more common in people with darker skin tones and can be addressed with topical agents like hydroquinone, azelaic acid, and vitamin C, as well as chemical peels. Sunscreen is critical during treatment since UV exposure darkens the marks further. The distinction matters because spending money on scar treatments when you have flat discoloration is wasteful, and some aggressive scar treatments could actually trigger more hyperpigmentation.
Why Skin Tone Changes the Treatment Plan
People with darker skin (generally Fitzpatrick types IV through VI) face a real dilemma with acne scar treatment. The most powerful resurfacing tools, particularly ablative fractional lasers, carry a higher risk of triggering post-inflammatory hyperpigmentation, which can leave you with new dark marks in exchange for slightly smoother texture. The risk depends on the specific device, the energy used, and especially the density of the treatment pattern.18PubMed. Energy-based devices in the treatment of acne scars in skin of color
Non-ablative fractional lasers have become the default first-line choice for acne scars in darker skin because of their better safety profile, even though they require more sessions and produce somewhat less dramatic results per session. Radiofrequency microneedling offers another good option since its energy is delivered through needles below the skin surface rather than through melanin-absorbing light, which reduces the risk of pigment changes. And combination protocols using subcision plus filler or fractional laser have shown significant and persistent improvement in Fitzpatrick skin types IV through VI without considerable complications.19Dermatological Reviews. Efficacy of a combination approach using subcision, fillers, and fractional carbon dioxide laser for the treatment of facial acne scars in Fitzpatrick skin types IV–VI
A dermatologist experienced with treating darker skin tones will typically start with conservative settings and evaluate pigment response before increasing intensity. This slower approach adds time and sessions but dramatically reduces the chance of trading one cosmetic problem for another.
Why Most People Need Combination Treatments
Dermatologists increasingly treat acne scars with layered protocols rather than relying on a single modality. The logic is straightforward: because most patients have multiple scar types simultaneously, a treatment plan that combines type-specific procedures (TCA CROSS for ice picks, subcision for rolling scars) with broad resurfacing (fractional laser or RF microneedling) addresses the full picture more effectively than any one treatment alone.
A study combining laser-assisted subcision with fractional CO2 laser found a mean improvement of more than 90 points on a validated scar severity scale, with no severe adverse effects.20PubMed Central. Subdermal Laser-Assisted Scar Subcision (SLASS) Combined With Fractional CO(2) Laser for Acne Scars: Efficacy Evaluation The optimal approach depends on more than just scar type. Skin tone, budget, tolerance for downtime, and the total number of scars all factor into the plan.21PubMed. Procedural and surgical treatment modalities for acne scarring: Part II Treatment needs to be selected considering these individual differences alongside economic realities.22PeerJ. Optimal treatment options for acne scars in patients with historic acne: a systematic review and network meta-analysis
A realistic combination plan might look like subcision of the deepest rolling scars in the first session, TCA CROSS on ice pick scars a few weeks later, and a round of fractional laser resurfacing once the targeted treatments have healed. Filler injections can be used between sessions to lift persistent deep scars. This kind of staged approach stretches cost over time but tends to produce more complete results than repeating the same procedure over and over.
PRP as an Add-On to Microneedling
Platelet-rich plasma (PRP), drawn from your own blood and concentrated, is sometimes applied to the skin immediately after microneedling. The idea is that the concentrated growth factors in PRP amplify the collagen-remodeling response that microneedling already triggers.23PubMed Central. Split Face Comparative Study of Microneedling with PRP Versus Microneedling with Vitamin C in Treating Atrophic Post Acne Scars Results from split-face studies (where one side of the face gets PRP and the other gets a comparison like vitamin C) suggest PRP adds some benefit, though the evidence is still relatively thin compared to the evidence base for lasers and subcision. PRP is not a standalone scar treatment, but it can be a useful adjunct if you are already undergoing microneedling.
Topical Retinoids and Preventing New Scars
Tretinoin (prescription-strength retinoid) does not erase established scars on its own, but it plays a supporting role in scar management. A randomized controlled trial found that topical tretinoin at 0.025% applied twice daily to healing wounds was effective at preventing hypertrophic scars and keloids, performing comparably to silicone gel.24PubMed Central. An Updated Review of Topical Tretinoin in Dermatology: From Acne and Photoaging to Skin Cancer – Section: Prevention of Hypertrophic Scars and Keloids For someone with active acne who is trying to prevent scarring in the first place, retinoids serve double duty by reducing acne and potentially reducing the scarring risk from the breakouts that do occur.
Retinoids also help with skin turnover and collagen production over time, which can modestly improve the appearance of shallow scars and improve the results of other procedures. Most dermatologists recommend stopping retinoids a week or so before ablative laser treatments or deep chemical peels, then resuming once healing is complete.
What to Expect After Procedures
Recovery looks different depending on what was done. After ablative fractional laser, expect about a week of crusting and redness that can linger for a couple of weeks beyond that. Non-ablative treatments usually involve just a couple of days of mild peeling and redness. Subcision can cause bruising and swelling for a week or more. TCA CROSS produces small white frost marks that scab over and peel within a week.
Post-procedure skin care matters for results. After treatments that disrupt the skin barrier, the focus should be on repair. Occlusive moisturizers help act as a temporary barrier while the skin heals, and formulations containing peptides or growth factors may support faster barrier restoration.25Aesthetic Surgery Journal Open Forum. Recommendations on Periprocedural Skincare for Energy-Based Dermatologic Procedures Sunscreen is non-negotiable after any resurfacing treatment, especially for people prone to hyperpigmentation. Avoid active ingredients like retinoids, vitamin C serums, and exfoliating acids until the skin has fully healed, usually a minimum of five to seven days for lighter procedures and longer for ablative lasers.
The Emotional Weight of Acne Scars
The psychological toll of acne scarring is well documented and often underestimated by people who do not have visible scars themselves. Greater perceived scar severity is linked to higher anxiety, lower confidence, reduced life satisfaction, and impaired social participation.26PubMed Central. Beyond the Surface: A Deeper Look at the Psychosocial Impacts of Acne Scarring A multi-country survey found that even people with mild scars reported significant embarrassment and self-consciousness, and the impact on quality of life increased with scar severity.27PubMed Central. Impact of Facial Atrophic Acne Scars on Quality of Life: A Multi-country Population-Based Survey In one study focused on depression and body image, all patients reported that their facial scarring had a very large effect on quality of life, leading to feelings of embarrassment and interference with sexual and personal relationships.28PubMed Central. Depression, body image and quality of life in acne scars
This context matters when you are deciding whether scar treatment is “worth it.” Insurance rarely covers cosmetic scar treatment, and the cumulative cost of a multi-session combination plan can run into thousands of dollars. But for people whose scarring genuinely affects how they move through the world, the impact on self-esteem and social functioning is real and measurable. If cost is a barrier, starting with targeted lower-cost treatments like TCA CROSS for ice pick scars or at-home microneedling for mild rolling scars and layering on professional treatments over time is a reasonable strategy. The key is working with a dermatologist who will assess your specific scar types, skin tone, and goals rather than applying a one-size-fits-all protocol.