Tranexamic acid versus fractional carbon dioxide laser in post-acne hyperpigmentation.

Post-acne hyperpigmentation is a common undesirable sequela of acne vulgaris that causes distress for many patients. This study's objective was to compare the efficacy of both low-power/low-density fractional carbon dioxide (CO2 ) laser and tranexamic acid (TXA) microinjection on post-acne hyperpigmentation. Twenty-five post-acne hyperpigmentation patients (resistant to regular treatment for more than 6 months) were enrolled in this randomized split-face study. One side of the face was randomly assigned to low-power fractional CO2 laser every 4 weeks, and the other side was assigned to TXA intradermal-microinjection every 2 weeks for 3 months. Efficacy was evaluated using digital photography, dermoscopy, post-acne hyperpigmentation index (PAHPI), melanin index (MI), and erythema index (EI) at baseline and 4 weeks after the last session. Both fractional CO2 laser and TXA microinjection treatment sides showed a significant reduction in the PAHPI and MI (p < 0.001). There was statistically significant difference with better percentage of improvement regarding total dermoscopic score on the fractional CO2 laser side than the TXA microinjections side (p < 0.009). Both fractional CO2 laser and TXA microinjection are effective and safe treatment options for post-acne hyperpigmentation with potential superiority of fractional CO2 laser. We also believe that dermoscopy could be helpful tool for assessment of pigmentation depth in patients on treatment by analyzing the color pattern. ClinicalTrials.govID: NCT03765021.