Intralesional Injection of Botulinum Toxin Type A Compared with Intralesional Injection of Corticosteroid for the Treatment of Hypertrophic Scar and Keloid: A Systematic Review and Meta-Analysis

BACKGROUND: The optimal treatment for hypertrophic scar and keloid remains controversial. Therefore, the aim of this systematic review and meta-analysis was to compare the effectiveness of intralesional injection of botulinum toxin type A compared with placebo and intralesional injection of corticosteroid compared with placebo in patients with hypertrophic scar and keloid. MATERIAL/METHODS: Six databases were searched using Medical Subject Headings (MeSH) keywords and included Web of Science, PubMed, EMBASE, the Cochrane Library, WanFang, and CNKI from their inception to March 1 2019, without language restriction. Randomized controlled trials (RCTs) and prospective controlled trials (PCTs) were identified that compared intralesional injection of botulinum toxin type A with placebo and corticosteroid with placebo in hypertrophic scar and keloid. The quality of controlled trials was assessed by the Newcastle-Ottawa Scale (NOS). RESULTS: Comparison of intralesional botulinum toxin type A and corticosteroid showed significant differences in the Visual Analog Scale (VAS) (P<0.001) (WMD, −4.30; 95% CI, −4.44 to −4.16) and effective rate (P=0.012) (RR=0.82; 95% CI, 0.70–0.96). Intralesional injection of botulinum toxin type A compared with placebo showed significant differences in the VAS (P<0.001) (WMD, 1.41; 95% CI, 1.21–1.62), the width of scar (P=0.00) (WMD, −0.15; 95% CI, −0.19 to −0.10) and Vancouver Scar Scale (VSS) (P=0.003) (WMD, −0.69; 95% CI, −1.14 to −0.23). CONCLUSIONS: Systematic review and meta-analysis showed that injection of intralesional botulinum toxin type A was more effective in the treatment of hypertrophic scar and keloid than injection of intralesional corticosteroid or placebo.