Background: Topical anesthetics are important tools for many dermatologic procedures. The S-Caine Peel is composed of a 1:1 (w:w) eutectic mixture composed of lidocaine base 7%, USP, and tetracaine base 7%, USP. It is applied as a cream, dries on exposure to air, and forms a flexible membrane, which can be easily peeled off.
Objective: To evaluate the effectiveness of the S-Caine Peel in providing clinically useful local dermal anesthesia for laser-assisted tattoo removal and to monitor the nature and frequency of adverse events associated with the safety of the S-Caine Peel.
Methods: Thirty adult patients undergoing laser-assisted tattoo removal were enrolled in this multicentered, randomized, double-blind, placebo-controlled study. Each subject received both the S-Caine Peel and placebo simultaneously for 60 minutes. The primary efficacy parameter was a 100 mm visual analog scale (VAS) for patient self-assessment of pain. Secondary efficacy parameters included both the investigator's and an independent observer's evaluation of subject pain (4-point categorical scale: no pain through severe pain) and the patient's and the investigator's overall impression of the local anesthetic.
Results: Mean VAS scores were 42 mm for the S-Caine Peel and 66 mm for placebo treatment sites (p=.001). Patients received adequate pain relief in 50% of S-Caine Peel sites versus 7% of placebo sites (p=.002). The percentage of those who would like to use the S-Caine Peel again were 43% for the S-Caine Peel compared with 7% for placebo (p=.005). Investigators' evaluations revealed that 70% of patients had less pain at S-Caine Peel treatment sites compared with 10% with less pain at placebo sites (p<.001), and 70% of the S-Caine Peel-treated sites achieved adequate anesthesia versus 10% of placebo sites (p<.001). The independent witness assessed less pain in 67% of S-Caine Peel-treated sites versus 10% of the placebo sites (p=.002). One occurrence of moderate to severe erythema was noted at both an S-Caine Peel and a placebo treatment site on removal of the S-Caine Peel after 60 minutes, which self-resolved quickly. There was no statistical difference between the two groups. Other side effects were limited to local mild, transient erythema at the application sites.
Conclusion: Administration of the S-Caine Peel for 60 minutes prior to laser-assisted tattoo removal was effective in significantly reducing pain levels associated with the procedure.