A randomized controlled trial comparing treatment regimens for acute pain for topical oleoresin capsaicin (pepper spray) exposure in adult volunteers.

Objective: Several topical therapies have been proposed to treat acute pain from exposure to oleoresin capsaicin (OC). The purpose of this study was to determine the most beneficial topical treatment for relieving contact dermatitis pain caused by OC exposure.

Methods: We performed a single-blind, randomized human experiment evaluating the effectiveness of five different regimens for the treatment of topical facial OC exposure. Forty-nine volunteer, adult law enforcement trainees were exposed to OC during a routine training exercise and were randomized to one of five treatment groups (aluminum hydroxide-magnesium hydroxide [Maalox], 2% lidocaine gel, baby shampoo, milk, or water). After initial self-decontamination with water, subjects rated their pain using a 10-cm visual analog scale (VAS) and then every 10 minutes, for a total of 60 minutes. Subjects were blinded to previous VAS recordings. A two-factor analysis of variance (ANOVA) (treatment, time) with repeated measures on one factor (time) was performed using a 1.3-cm difference as clinically significant.

Results: Forty-four men and five women, with an average age of 24 years, participated in the study. There was a significant difference in pain with respect to time (p < 0.001), but no significant interaction between time and treatment (p > 0.05). There was no significant difference in pain between treatment groups (p > 0.05).

Conclusion: In this study, there was no significant difference in pain relief provided by five different treatment regimens. Time after exposure appeared to be the best predictor for decrease in pain.