To date, there has been little study of comparison between picosecond 532 nm laser and 755 nm Q-switched Alexandrite lasers in the treatment of freckles. To evaluate the efficacy and safety of picosecond 532 nm laser (PS 532) and 755 nm Q-switched Alexandrite laser (QSAL) for treatment of freckles in a split-face manner. Eighteen patients with freckles were enrolled in the study. The right and left sides of their faces were randomly assigned to either a QSAL-treated group or PS 532-treated group. The degree of pain, satisfaction with the results, and adverse events associated with the laser treatment were evaluated using a questionnaire. All of the patients were followed up at 4 and 12 weeks after one treatment session. Among the 18 patients, PS 532 was found to be associated with less pain (3.56 ± 2.431) than QSAL (3.94 ± 1.893), but the difference was not statistically significant. The curative effect and satisfaction associated with 755 nm Q-switched Alexandrite laser was greater than that of picosecond 532 nm laser (P < .001). Both picosecond 532 nm laser and QSAL are effective in the treatment of freckles, and QSAL has a greater rate of satisfaction and curative effect.
Keywords: Freckles; alexandrite laser; picosecond laser.