Botulinum Toxin Type A for Rosacea Flushing: A Review

Abstract

Introduction: Erythematotelangiectatic rosacea features refractory flushing. Botulinum toxin type A (BoNT-A) may inhibit vasodilation via cholinergic blockade. This review evaluates its efficacy. Methods: Nine studies (2 RCTs, 7 open-label; n=184) with BoNT-A intradermal injections. Outcome: clinician erythema score and patient-reported flushing episodes. Results: BoNT-A reduced erythema severity by 55% at 4 weeks (p<0.001). Flushing episodes decreased from 7.2 to 1.8 per week. Duration of effect 3–6 months. Adverse events: temporary frontalis weakness (12%), bruising (20%). Discussion: Mechanism likely involves blocking acetylcholine-induced nitric oxide release from endothelial cells. Lack of standardized injection doses (10–40 units per side) limits meta-analysis. Conclusions: BoNT-A appears promising for refractory rosacea flushing, but larger sham-controlled trials are needed.