Solutions contre les cicatrices d'acné.

Can acne scars be eliminated?

Acne is a skin condition that can harm self-confidence and the skin itself. Depending on its severity, it can leave scars that persist long after the last blemish resolves. Are there methods to reduce them and restore an even skin tone? Discover here whether it is possible to fade acne scars.

Summary
Published January 10, 2022, updated on June 24, 2025, by Stéphanie, PhD, Doctorate in Life and Health Sciences — 13 min read

The different types of acne scars.

There are several types of acne scars. It is important to distinguish them for effective management. Note that we refer to scars when the mark remains visible one year after the lesion has healed.

  • Atrophic scars : Atrophic scars appear as depressions in the skin. They develop when a blemish fails to heal and connective tissue formation is insufficient. The size and depth vary. They can take three forms. First, ice-pick or V-shaped scars: narrow and deep. Second, U-shaped or crater scars: wide, shallow, with sharp or rounded edges. Third, boxcar scars: wide and deep.

  • Hypertrophic scars : Hypertrophic scars, also known as raised scars, are swollen bumps characterized by an overgrowth of skin tissue. They form when a second layer of skin covers scar tissue during acne healing. These scars result from an excess of collagen.

Acne scars can be mistaken for red spots (post-inflammatory erythema) or brown spots (post-inflammatory hyperpigmentation) left by pimples. Although these can persist on the skin for several months, they involve only the superficial layers of the epidermis and do not cause depressions or elevations in the skin.

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How to reduce acne scars?

If acne is severe, no effective treatment can fade or erase scars except surgery or aesthetic medicine.

Before considering any acne scar treatment, you must ensure the inflammatory phase has ended. If you underwent a course of isotretinoin (formerly Roaccutane), it should have ended at least six months earlier. This step matters because scar treatments may be ineffective and could trigger an inflammatory response and a new acne breakout. To reduce scars left by acne lesions, here are the available options.

Treatment No. 1 for acne scars: dermatologic peel.

Dermatological peeling is a procedure used to remove atrophic and hypertrophic scars. It requires applying a potent exfoliant to the skin, often phenol at 15%–60% or trichloroacetic acid (TCA) at 10%–70%. Chemical peeling triggers controlled destruction of part or all of the epidermis, with or without the dermis, leading to shedding of superficial lesions followed by regeneration of new epidermal and dermal tissue, yielding smoother skin with less visible scars. After a dermatological peel, the skin is sensitive. A healing cream should be applied each day for the weeks after treatment, and sun exposure must be avoided.

A study investigated the effects of a 70% TCA peel on atrophic scars in 53 patients. They were monitored over three months. A good or excellent improvement (>50%) was observed in 66% of patients, and 81.1% reported being satisfied to very satisfied.

Peeling dermatologique au TCA (70%) : avant/après à 3 mois.
70% TCA dermatological peel: before and after at three months.
Source: Mittal A. et al. Therapeutic response to 70% trichloroacetic acid CROSS in atrophic acne scars. Dermatologic Surgery. 2015.

Treatment No. 2 for acne scars: microdermabrasion.

Microdermabrasion is a noninvasive, gentle method that can help reduce acne scars. Its principle relies on a controlled mechanical exfoliation of the outer layers of the epidermis, using high-velocity microcrystals of aluminum oxide, or via a diamond abrasive tip. This abrasion stimulates cell turnover, promotes removal of dead cells and accelerates skin regeneration. By inducing mild local inflammation, microdermabrasion triggers collagen production and improves skin texture. To achieve visible improvement in acne scars, multiple sessions are required—between five and ten—spaced two to three weeks apart. Microdermabrasion carries a low risk of side effects when performed by a trained professional.

Treatment No. 3 for acne scars: laser therapy.

Laser therapy is effective for treating hypertrophic scars. It induces controlled skin injury by delivering successive laser pulses to the targeted area to stimulate cell renewal. A wide range of lasers is available: Fraxel laser, CO2, etc... This technique aims to even skin texture by correcting small depressions or elevations caused by acne. Laser treatment requires multiple sessions to reduce scars and achieve lasting results. Some studies also indicate that combining laser with another therapy can aid in removal of acne scars.

It is possible to combine a fractional ablative CO2 laser treatment with fractional microplasma radiofrequency. A study with 64 patients showed that this combination reduced acne scar visibility more than the laser alone. Another study with 30 patients applied a fractional CO2 laser to one side of the face and a fractional CO2 laser followed by intradermal platelet-rich plasma (PRP) injections to the other side. Both groups showed satisfactory outcomes. However, the combined treatments yielded greater improvement in atrophic scars.

Treatment No. 4 for acne scars: hyaluronic acid injections.

Injections of hyaluronic acid are used to soften shallow atrophic scars, including wave-shaped scars. The procedure relies on targeted hyaluronic acid injections beneath the skin depression to restore volume and smooth the skin surface. This mechanical filling reduces skin irregularity. Because hyaluronic acid is naturally resorbed by the body, its effects are temporary: a new injection is required every 6 to 12 months to maintain results. Considered safe, hyaluronic acid injections should not be taken lightly: this aesthetic medicine procedure must be performed by a professional and may cause side effects (edema, redness, infections).

Treatment No. 5 for acne scars: radiofrequency.

Radiofrequency is a technique that relies on the emission of high-frequency electromagnetic waves capable of heating the deep dermal layers without harming the epidermis. This thermal effect stimulates fibroblast activity, the cells responsible for collagen and elastin synthesis. By reactivating this skin regeneration process, radiofrequency improves dermal density and firmness. It is suited for reducing moderate atrophic scars by partially restoring lost volume. The protocol involves three to four sessions spaced about one month apart to induce sufficient collagen production and achieve a visible, lasting result. Numerous studies have evaluated radiofrequency for reducing acne scars. The results of several are presented in the table below.

AuthorsNumber of patientsType of radiofrequencyNumber of sessionsResults
Kim et al.52Fractional microneedle radiofrequency4 sessions73.1% of patients showed improvement.
CHANDRASHEKAR et al.31Radiofrequency microneedlingFour sessions over six months (every six weeks)80.64% of grade 3-4 scars improved by two grades, 19.35% by one grade
ELAWAR & al.53Radiofrequency microneedlingTwo to four sessions (every four weeks)Significant scar improvement
Kim et al.Not specifiedFractional bipolar radiofrequencyFour sessions (every three weeks)Significant improvement in elasticity and increased synthesis of type I and III procollagen
QIN & al. Radiofrequency (unspecified type)Four sessions (every four weeks)Significant improvement in acne scars
Summary of studies on radiofrequency efficacy for acne scars.
Source: Nowicka D. et al. Methods for improving acne scars in dermatology and cosmetology: a review. Journal of Clinical Medicine (2022).

Treatment No. 6 for acne scars: corticosteroid injections.

Another option to treat hypertrophic acne scars is intralesional corticosteroid injections. It involves injecting a cortisone derivative—triamcinolone acetonide at concentrations of 10 to 40 mg/mL—into the lesion. The goal is to reduce scar volume. This is achieved by the antimitotic effect of the injected corticosteroids, which inhibit fibroblast and keratinocyte proliferation that drive excessive collagen production. Corticosteroids may also promote degradation of accumulated collagen by inhibiting alpha-2-macroglobulin, a molecule that protects collagen deposits.

To optimize product diffusion in scar tissue, light cryotherapy with liquid nitrogen can be performed 10 to 15 minutes before injection. Use of a topical anesthetic cream or concurrent lidocaine injection is often recommended to improve patient comfort. Potential adverse effects include depigmentation, skin atrophy, telangiectasias, or, less commonly, local infections.

Treatment No. 7 for acne scars: microneedling.

Microneedling is a skin stimulation technique that involves creating microperforations on the skin surface using multiple ultrafine needles shorter than 0.5 mm. These superficial microinjuries signal repair and trigger a regenerative cascade in the skin. This physiological response leads to new collagen fiber synthesis and structural remodeling, helping reduce the appearance of acne scars. The main advantage of microneedling is its low invasiveness. It is a clinical procedure with limited downtime and a low risk of adverse effects when performed by a trained professional.

A prospective clinical study evaluated microneedling in atrophic acne scar management. Ten patients with various atrophic scar types underwent six microneedling sessions over three months, spaced two weeks apart. All participants showed visible scar improvement. Histological analyses revealed a significant increase in type I, III, and VII collagen and synthesized collagen. A significant decrease in total elastin was observed, suggesting extracellular matrix remodeling toward a more functional structure. The table below provides details on extracellular matrix changes after microneedling.

CriteriaBefore treatment1 month after treatment initiation (2 sessions)Three months after the start of treatment (six sessions)
Epidermal thickness (µm)63 ± 4,972 ± 7.180.2 ± 3.8
Type I collagen (%) 70.4 ± 5.478.2 ± 6.8
Collagen III (%)61.4 ± 3.665,5 ± 6,174.3 ± 7.4
Type VI collagen (%)15,2 ± 2,116.4 ± 1.721,3 ± 1,2
Newly synthesized collagen (%)14.5 ± 5.815,8 ± 5,319.5 ± 3.2
Elastin (%)51,3 ± 6,7… 50,1 ± 4,746,9 ± 4,3
Quantitative analysis of epidermal thickness and extracellular matrix proteins before and after microneedling treatment for post-acne atrophic scars.
Source: MEDHAT W. et al. Microneedling therapy for atrophic acne scars: an objective evaluation. Journal of Clinical and Aesthetic Dermatology (2015).

Advice : Acne scars are difficult to eliminate. Preventive measures can reduce their occurrence. Avoid touching your pimples and do not delay consulting a dermatologist if you have acne. The more severe the acne and the later treatment begins, the higher the risk of scarring.

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