The level of evidence is downgraded by study limitations (several issues) and indirectness (heterogeneity in interventions and outcomes, short follow-up times)
A Cochrane review «Interventions for acne scars»1 «Abdel Hay R, Shalaby K, Zaher H et al. Interventions for acne scars. Cochrane Database Syst Rev 2016;(4):CD011946. »1 included 24 studies with a total of 789 subjects aged 18 years or older. Twenty trials enrolled men and women, three trials enrolled only women and one trial enrolled only men.
For the outcome 'Participant-reported scar improvement' in one study fractional laser was more effective in producing scar improvement than non-fractional non-ablative laser at week 24 (RR 4.00, 95% CI)1.25 to 12.84; n = 64); fractional laser showed comparable scar improvement to fractional radiofrequency in one study at week eight (RR 0.78, 95% CI 0.36 to 1.68; n = 40) and was comparable to combined chemical peeling with skin needling in a different study at week 48 (RR 1.00, 95% CI 0.60 to 1.67; n = 26). In a further study chemical peeling showed comparable scar improvement to combined chemical peeling with skin needling at week 32 (RR 1.24, 95% CI 0.87 to 1.75; n = 20). Chemical peeling in one study showed comparable scar improvement to skin needling at week four (RR 1.13, 95% CI 0.69 to 1.83; n = 27). In another study, injectable fillers provided better scar improvement compared to placebo at week 24 (RR 1.84, 95% CI 1.31 to 2.59; n = 147).
For the outcome ‘Serious adverse effects’ in one study chemical peeling was not tolerable in 7/43 (16%) participants (RR 5.45, 95% CI 0.33 to 90.14; n = 58). For the secondary outcome ‘Participant-reported short-term adverse events’, all participants reported pain in the following studies: in one study comparing fractional laser to non-fractional non-ablative laser (RR 1.00, 95% CI 0.94 to 1.06; n = 64); in another study comparing fractional laser to combined peeling plus needling (RR 1.00, 95% CI 0.86 to 1.16; n = 25); in a study comparing chemical peeling plus needling to chemical peeling (RR 1.00, 95% CI 0.83 to 1.20; n = 20); in a study comparing chemical peeling to skin needling (RR 1.00, 95% CI 0.87 to 1.15; n = 27); and also in a study comparing injectable filler and placebo (RR 1.03, 95% CI 0.10 to 11.10; n = 147). For our outcome ‘Investigator-assessed short-term adverse events’, fractional laser (6/32) was associated with a reduced risk of hyperpigmentation than non-fractional non-ablative laser (10/32) in one study (RR 0.60, 95% CI 0.25 to 1.45; n = 64); chemical peeling was associated with increased risk of hyperpigmentation (6/12) compared to skin needling (0/15) in one study (RR 16.00, 95% CI 0.99 to 258.36; n = 27). There was no difference in the reported adverse events with injectable filler (17/97) compared to placebo (13/50) (RR 0.67, 95% CI 0.36 to 1.27; n = 147).
Date of latest search: 2015-11-18