Evaluating the efficacy of combining fractional CO2 laser and topical tranexamic acid for burn scar and hyperpigmentation treatment: A prospective, randomized, single-blinded, split-body study

Abstract Background: A fractional carbon dioxide (CO 2 ) laser can improve the appearance of burn scars. In addition, tranexamic acid (TXA) inhibits melanin production for whitening effects. Laser-assisted drug delivery (LADD) technology utilizes lasers to enhance the percutaneous absorption of drugs. Objectives: The purpose of this study was to investigate whether the use of a fractional CO 2 laser in combination with TXA can further improve pigmentation in burn scars. Methods: This prospective, randomized, single-blinded, split-body study included patients aged 20 years and older who had burn scars with associated hyperpigmentation for more than 6 months. A total of 12 patients were included between September 1, 2019, and August 31, 2020. For each patient, their pigmented burn scar was divided into two sides along the midline. One scar side received fractional CO 2 laser alone, and the other combined fractional CO 2 laser and topically applied TXA solution. Treatment sessions were conducted monthly for a total of three times. Photographs were captured at baseline and 3 months after completing the 3 monthly treatment sessions. Four plastic surgeons, blinded to the treatment sides, compared the improvement on both sides of each patient based on the photographs. The patients’ reported satisfaction levels were also recorded. Results: In the physician assessments, both methods showed a noticeable improvement in scar appearance and pigmentation. On a scale of 1 to 10, physicians rated the overall improvement in scar appearance between 4.6 and 5.6 points, while the improvement in overall hyperpigmentation ranged from 6.0 to 6.9 points. The average patient satisfaction score was 8.4 ± 1.6 points. However, there was no significant difference in the improvement of outcomes between the two methods, with or without the addition of TXA treatment. Conclusion: This study shows that fractional CO 2 laser treatment significantly improves burn scars and hyperpigmentation. However, adding TXA shows no clear additional benefits. Before making the final conclusion based on the results from the small patient sample size, further research is encouraged to clarify the delivery pathways in applying TXA and explore the mechanisms behind LADD.