Single-Center, Double-Blind, Randomized Study to Evaluate the Efficacy of 4% Lidocaine Cream versus Vehicle Cream During Botulinum Toxin Type A Treatments

BACKGROUND: Botulinum toxin type A (BTX-A) injections are overwhelmingly safe and effective treatment in cosmetic treatment, but some patients are apprehensive about pain associated with injection. OBJECTIVE: To determine whether preprocedural application of lidocaine 4% topical anesthetic cream to the injection site will reduce pain on injection of BTX-A for the treatment of crow's feet. METHODS: Twenty-four participants receiving bilateral injections for crow's feet were enrolled. Subjects were randomized to one of four study groups. Prior to BTX-A injection, group 1 (n = 6) received lidocaine 4% cream on the right side of the face and vehicle cream on the left side of the face; group 2 (n = 6) received vehicle cream on the right side and lidocaine 4% on the left side; group 3 (n = 6) received lidocaine 4% on both sides; and group 4 (n = 6) received vehicle cream on both sides. RESULTS: We observed a statistically significant reduction in subject-reported procedural pain in participants pretreated with lidocaine 4% on both sides of the face compared with controls. CONCLUSION: Lidocaine 4% cream is effective in reducing the pain associated with BTX-A injection for crow's feet. We encourage further study to clarify the optimal use of topical anesthetics in the practice of cosmetic dermatology.