Atrophic acne scars: types and treatment in 2026

Atrophic acne scars are permanent depressions in the skin caused by collagen loss after inflammatory acne heals. They are commonly grouped into three shapes that behave differently under treatment: narrow, deep ice-pick scars; sharply walled boxcar scars; and broad, tethered rolling scars [1]. This shape-based classification matters because the most effective approach is matched to the scar type rather than applied uniformly, and because most patients improve more with a combination of methods than with a single device [1][2].

This article summarizes how atrophic acne scars are categorized and what the current evidence supports for the main treatment categories: subcision, focal trichloroacetic acid (TCA CROSS), fractional lasers, microneedling radiofrequency, fillers and biostimulators, and platelet-rich plasma. It is not medical advice; assessment and treatment should be directed by a board-certified dermatologist.

How atrophic scars form

Acne inflammation damages the dermis and the structures that anchor the skin. When repair produces too little collagen, the surface heals below its original level, leaving a depression. The depth, wall steepness, and degree of tethering to deeper tissue determine the scar's shape and how it responds to treatment [1]. Because the collagen deficit is structural, topical products alone do not correct established atrophic scars; effective treatments work by remodeling the dermis or releasing tethered scars.

The three scar types

Most patients have a mixture of types, which is why treatment plans are often layered rather than singular [1].

Matching treatment to scar type

Subcision for rolling scars

Subcision uses a needle or blunt cannula to release the fibrous bands that tether rolling scars to deeper tissue, allowing the surface to lift. The systematic review of non-energy techniques reported improvement across a wide range after subcision, and the procedure is frequently combined with resurfacing or filler to maintain the correction [1].

TCA CROSS for ice-pick scars

The chemical reconstruction of skin scars (CROSS) technique applies a high concentration of trichloroacetic acid to the base of a narrow scar to stimulate localized collagen formation. In the same review, focal TCA achieved meaningful improvement in a majority of treated patients with deep, narrow scars, where broad resurfacing is less effective [1].

Fractional lasers and microneedling radiofrequency

Fractional ablative lasers and microneedling radiofrequency create controlled microscopic injuries that drive dermal remodeling, and both are mainstays for boxcar and mixed atrophic scarring. A randomized split-face trial in patients with acne and acne scars found that combining fractional microneedling radiofrequency with an ablative fractional laser produced greater improvement in scar grading and lesion counts than the laser alone, with side effects that were minimal and well tolerated [2]. Combination and staged device strategies are a recurring theme in the evidence.

Fillers and biostimulators

Soft-tissue fillers can lift depressed scars, and biostimulatory injectables add a collagen-building component. A randomized controlled trial found that injecting poly-L-lactic acid after CO2 fractional laser treatment improved scarring scores more than the laser alone, with the largest gains in rolling scars, followed by boxcar scars, and the least change in ice-pick scars [3]. Reported adverse reactions were transient redness, bruising, and pigmentation.

Platelet-rich plasma as an adjunct

Platelet-rich plasma (PRP) is often added to laser or microneedling treatment. A systematic review and meta-analysis reported that PRP alone produced response rates comparable to laser or microneedling, and that adding PRP to those procedures increased the proportion of patients with marked or excellent results while reducing post-procedure side effects such as redness and downtime [4]. PRP is best understood as a complementary step rather than a standalone cure.

Skin tone considerations

The main safety concern across resurfacing and needle-based treatments is post-inflammatory hyperpigmentation, which is more common in Fitzpatrick III to VI skin. Conservative settings, longer intervals between sessions, test spots, diligent sun protection, and pigment-directed aftercare lower that risk. Patients with a history of keloids or hypertrophic scarring need individualized planning, because aggressive resurfacing can provoke raised scars in susceptible skin.

Adverse events, limitations, and realistic expectations

• Improvement, not erasure. The evidence base describes partial improvement that accumulates over multiple sessions and months of remodeling, not complete removal [1][3].
• Multiple sessions are the norm. Most energy-based and needle-based treatments are delivered as a series, and benefits continue to develop for weeks after each session [2].
• Expected short-term effects include redness, swelling, bruising, crusting, and temporary pigment change; these are usually transient but vary by device and skin type [3].
• Pigmentation risk is the principal limitation in darker skin and is managed with conservative settings and sun protection.
• Control active acne first. New inflammatory lesions can create fresh scars and complicate healing, so scar treatment generally follows control of active disease (see our adult female acne guide).
• Evidence quality varies. Many studies are small and use different scar-grading scales, which limits direct comparison between devices and protocols [1][4].

Bottom line

Atrophic acne scars respond best when treatment is matched to scar shape and layered over several sessions. Subcision targets tethered rolling scars, focal TCA addresses narrow ice-pick scars, and fractional lasers and microneedling radiofrequency remodel boxcar and mixed scarring, with fillers, biostimulators, and PRP used to enhance results [1][2][3][4]. Realistic counseling centers on meaningful reduction in scar depth and visibility rather than complete removal, with particular attention to pigmentation risk in darker skin.

This article is for informational purposes and does not constitute medical advice.