A Pilot Study to Evaluate the Efficacy and Safety of Treatment with Botulinum Toxin in Patients with Recalcitrant and Persistent Erythematotelangiectatic Rosacea

Background: There are few pharmacologic options to reduce erythema and flushing in patients with recalcitrant erythematotelangiectatic rosacea (ETR). We previously reported two cases of refractory flushing and erythema of rosacea that were successfully treated with intradermal botulinum toxin injection, and additional research is needed to prove the efficacy and safety of this treatment. Objective: To report the efficacy and safety of botulinum toxin injection as an aid in persistent erythema of rosacea patients. Methods: A total of 20 Korean patients with recalcitrant ETR were enrolled to receive treatment by injection of botulinum toxin. Patients received one treatment of intradermal botulinum toxin injection and were assessed 1, 2, 4, and 8 weeks after treatment. The severity of erythema and telangiectasia was investigated by a non-treating physician, and the Erythema Index (EI) was assessed by mexameter at each visit. Patient satisfaction and any adverse events were also assessed at each visit. Results: 17 patients completed all follow-up visits and were included in the analysis. Intradermal injection of botulinum toxin significantly reduced erythema severity and EI in ETR patients. Patients reported a satisfaction score of $2.94{\pm}0.56$ at 8 weeks after treatment. Except for three patients who discontinued the study early due to inconvenience of facial muscle paralysis, 17 patients participating in the final analysis did not report side effects except injection pain at the time of the procedure. Conclusion: Intradermal injection of botulinum toxin can be used as an effective and relatively safe adjuvant agent for recalcitrant and persistent erythema of ETR patients.