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 AND 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.

Keywords: 17-Hydroxycorticosteroids, Botulinum Toxins, Type A, Cicatrix, Hypertrophic, keloid, Adrenal Cortex Hormones, Injections, Intralesional