Efficacy of Botulinum Toxin in the Treatment of Cutaneous Flushing: A Systematic Review and Meta-Analysis

BACKGROUND Flushing is a common dermatologic complaint and can be resistant to many treatments. As the utility of botulinum toxin continues to expand, recent data suggest that it may also be a therapeutic option for flushing. OBJECTIVE To evaluate the efficacy of botulinum toxin for the treatment of cutaneous flushing. MATERIALS AND METHODS A systematic search of Medline, Embase, Cochrane CENTRAL, CINAHL, Scopus, and Web of Science databases was conducted to identify studies evaluating the effect of botulinum toxin on flushing 1 month after treatment. Prespecified outcome measures included a clinical flushing score, dermatology life quality index (DLQI), and erythema index (EI). Meta-analysis was performed to calculate the mean differences in these outcomes before and after treatment at 1-month follow-up. RESULTS Nine studies (132 patients) were included in the analysis of this study (2 randomized controlled trials and 7 nonrandomized studies). All studies had a low risk of bias (high quality). The most frequent outcome reported was a clinical flushing score, which significantly decreased by 1.25 points overall (95% confidence interval [CI]: −2.47; −0.04) 1 month after treatment with botulinum toxin. Mean DLQI scores decreased (i.e., improved) by 9.02 points (95% CI: −19.81; 1.77) 1 month after botulinum toxin injections. The EI (measured by Mexameter) before and after botulinum toxin was evaluated in 2 studies; however, not enough statistical information was provided to analyze with meta-analytic techniques. CONCLUSION Based on this meta-analysis, botulinum toxin significantly improves clinical flushing scores 1 month after treatment.