Intradermal Tranexamic Acid Injection for the Treatment of Melasma: A Pilot Study with 48-week Follow-up.

Despite being an effective treatment for melasma, there have been limited reports on the long-term efficacy of intradermal tranexamic acid (TA) injection. This study sought to evaluate the 48-week efficacy of a 4mg/mL intradermal TA injection for the treatment of melasma. Five female patients with melasma participated in the 48-week follow-up after receiving 4-mg/mL intradermal TA injections on the face every two weeks for seven sessions and a sunscreen prescription. Assessments were performed at baseline and Weeks 4, 8, 12, 16, and 48 using the modified Melasma Area Severity Index (mMASI) score, melanin index, and patient satisfaction score. Safety and adverse effects were also evaluated. The mean (standard deviation) age of patients was 53.6 (8.14) years and Fitzpatrick Skin Type IV (60%) and Fitzpatrick Skin Type V (40%) were observed. The mean (standard deviation) duration of melasma was 7.6 (2.51) years and 60 percent of participants reported a family history of melasma. There was a significant decrease in mMASI score and melanin index at 16 weeks, without a statistically significant improvement of mMASI score at 48 weeks. Melasma recurrence was observed in 60 percent of the participants, with higher mMASI scores recorded, but the severity remained less than at baseline. The patient satisfaction score was lower from Week 16 to Week 48. Interestingly, a statistically significant decrease in the melanin index was observed up to Week 48, with no serious adverse effects. The 4-mg/mL intradermal TA injection yields significant efficacy at Week 16; however, melasma recurrence occurred during the 48-week follow-up. In addition to tranexamic acid injections, maintenance therapy and sun protection should be considered for patients with melasma.