Fractional laser edges microneedling on non-acne scars

Design

systematic review and random-effects meta-analysis of nine randomised trials, PROSPERO registered, parallel-group and split-body designs

Population

patients with non-acne scars and scar-like dermal fibrotic lesions from trauma, burns and surgery

Primary outcome

overall scar severity score, with collagen and elastic fibre changes, epidermal thickness and adverse events

Effect

scar score SMD −0.99 (95% CI −1.83 to −0.15, P = 0.02) favouring fractional laser; collagen regeneration −2.14 (−3.57 to −0.72); no difference in adverse events

Microneedling is cheap, portable and needs no laser licence, which is why it has spread so widely for scar resurfacing. Whether it matches fractional laser outside acne scarring has not been settled. A meta-analysis pooled nine randomised trials — parallel-group and split-body — comparing the two for scars from trauma, burns and surgery and other dermal fibrotic lesions.

Fractional laser came out ahead on overall scar score, with a standardised mean difference of −0.99 (95% confidence interval −1.83 to −0.15, P = 0.02) favouring laser, and on histological collagen fibre regeneration (−2.14, −3.57 to −0.72). There was no difference in elastic fibre improvement, epidermal thickness or adverse events. Subgroup analysis did not separate carbon dioxide from non-carbon-dioxide platforms, or traditional from newer fractional systems — so the advantage appears to belong to fractional laser as a class rather than to any particular device.

Heterogeneity was substantial and the authors say so. Nine small trials with different scar types, different scoring instruments and different treatment intervals is a thin evidence base for a confident recommendation, and the confidence interval on the headline result reaches almost to zero. The honest reading for a clinic is that laser is probably the better resurfacing modality for non-acne scars where it is available and affordable, with no safety penalty — and that microneedling remains a defensible choice where it is not, rather than an inferior one that should be abandoned.

• Where both are available, offer fractional laser first for established non-acne scars.
• Do not choose a platform on this evidence — carbon dioxide and erbium systems were not separated.
• Counsel on adverse events the same way for both; the analysis found no difference.
• Set the scar score you will use before starting, since outcome instruments varied widely between trials.
• Cost and access matter here: microneedling remains reasonable where laser is not affordable or not available.

Why it matters

It gives a direction to a choice that has been made on equipment availability and habit rather than on comparative evidence.

Don't overread it

Substantial heterogeneity and nine small trials — this supports a preference, not a standard of care, and it does not identify which laser platform to buy.

The statistics, in plain English

A standardised mean difference of −0.99 sounds large, but the confidence interval runs from −1.83 to −0.15: the lower end would be a substantial clinical advantage and the upper end would be barely perceptible, so the size of the benefit is genuinely unresolved. The collagen result (−2.14) is a histological surrogate, not something a patient notices. Substantial heterogeneity across outcomes means the trials were not measuring the same thing in the same populations, which is why a pooled estimate here should guide a preference rather than settle a question.

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