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.
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.
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.