What it means for a patient
- For depressed acne scars on the face, the two approaches gave comparable improvement in this analysis.
- Fractional CO2 laser carried about three times the risk of skin darkening after treatment compared with standard microneedling.
- Radiofrequency microneedling scored higher for pain than fractional CO2 laser.
- The authors state that skin type, scar type and possible complications should guide the choice of treatment.
- The pooled studies differed widely in their results, which limits how firm the conclusions can be.
Why this paper matters
It pooled head-to-head studies of fractional CO2 laser and needling-based treatment for atrophic acne scars and reported effect and side effects side by side. The authors call for tailored treatments that carry a low risk of complications.
Overview
Acne can leave permanent depressed (atrophic) scars on the face. Fractional CO2 laser and needling procedures are both used to treat them, but data comparing their results and safety are limited. The authors searched PubMed, Cochrane, Google Scholar and ClinicalTrials.gov under PRISMA guidelines. They included only studies in adults that compared fractional CO2 laser with a needling-based treatment used alone, and pooled the results with a random-effects model in Review Manager.
Findings
- 17 studies were included in the meta-analysis.
- Mean scar score reduction: no significant difference (SMD -1.08, 95% CI -2.48 to 0.32; I² = 97%).
- Mean quantitative scar reduction: no significant difference (SMD 0.12, 95% CI -0.80 to 1.04; I² = 92%).
- Results for these two outcomes varied significantly between studies.
- Categorical treatment success favored CO2 laser (RR 1.10, 95% CI 1.01 to 1.20; I² = 0%).
- Post-inflammatory hyperpigmentation: higher risk with fractional CO2 than with standard microneedling (RR 3.04, 95% CI 1.49 to 6.21; I² = 3%).
- Pain: lower with fractional CO2 than with radiofrequency microneedling (SMD -0.74, 95% CI -1.27 to -0.21; I² = 0%).
- No significant differences in redness, crusting or scabbing, or swelling.
Terms
- Atrophic acne scar: a depressed scar left after acne.
- Fractional CO2 laser: a laser that treats tiny columns of skin and leaves the skin between them intact.
- Microneedling: treatment with fine needles that make small punctures in the skin to prompt healing.
- Radiofrequency (RF) microneedling: microneedling that also delivers heat through the needles.
- Post-inflammatory hyperpigmentation (PIH): darkening of the skin after injury or inflammation.
- Erythema: redness of the skin.
- Edema: swelling.
- Meta-analysis: a method that pools the results of several studies.
- Risk ratio (RR): how many times more likely an outcome is in one group than in another.
- Standardized mean difference (SMD): a measure that compares average results across studies that used different scales.
- Heterogeneity (I²): how much results differ between studies; a higher value means more difference.