What it means for a patient
- Laser with poly-L-lactic acid, laser with platelet-rich plasma, and microneedling with a chemical peel had lower average scar scores than laser alone.
- None of these differences was statistically certain.
- The authors state the evidence cannot rank acne scar treatments against each other.
- No trial measured which treatment works best for which scar shape.
- Limits: 9 trials, low to very low certainty, and a search limited to PubMed and PMC.
Why this paper matters
It combined randomized trials of acne scar treatments into one network and reported that current evidence does not support a treatment ranking.
Overview
Depressed (atrophic) acne scars differ in structure from patient to patient. The authors compared minimally invasive, energy-based and regenerative treatments, and discussed how scar type might guide future trials. They searched only PubMed and PMC, so eligible studies in other databases may have been missed.
Findings
- PROSPERO-registered review (CRD420261471957); PubMed/MEDLINE and PMC searched from inception to 20 June 2026.
- Embase, CENTRAL, Web of Science, Scopus, trial registries and gray literature were not systematically searched.
- Included: randomized and split-face randomized trials that reported extractable scar-severity outcomes.
- Network: 9 trials, 19 treatment arms, 11 direct comparisons and 10 nodes.
- Versus laser alone, laser plus PLLA: SMD -0.69 (95% CI -1.55 to 0.18).
- Versus laser alone, laser plus PRP: SMD -0.20 (95% CI -0.81 to 0.40).
- Versus laser alone, microneedling plus chemical peel: SMD -0.14 (95% CI -1.34 to 1.07).
- All confidence and prediction intervals crossed zero, the point of no difference.
- Heterogeneity was moderate to substantial (tau² = 0.124; I² = 65.3%).
- Most nodes were supported by 1 or 2 studies, and sensitivity analyses changed the top-ranked treatment.
- CINeMA rated the comparisons as low or very low confidence.
- No trial reported results by scar shape, so scar-type-based comparison could not be tested.
Terms
- Atrophic acne scar: a depressed scar left by acne.
- Network meta-analysis: a method that compares several treatments at once, using direct and indirect comparisons across trials.
- Node: one treatment in the network.
- Standardized mean difference (SMD): the size of a difference between treatments on a common scale; below zero here means less scar severity.
- Confidence interval (CI): the range in which the true value likely falls.
- PLLA (poly-L-lactic acid): an injectable that prompts the body to make collagen.
- PRP (platelet-rich plasma): a concentrate of the patient's own blood platelets, applied or injected to support healing.
- Microneedling: making many tiny punctures in the skin with fine needles.
- Split-face trial: a study that treats each side of the face differently in the same patient.
- CINeMA: a system for rating confidence in network meta-analysis results.