Localized Intradermal Microinjection of Tranexamic Acid for Treatment of Melasma in Asian Patients: A Preliminary Clinical Trial

Melasma is a common cosmetic problem among Asians. While various treatments are currently being used, there is no entirely satisfactory treatment. It was recently reported that the topical plasmin inhibitor is an effective treatment for ultraviolet-induced hyperpigmentation.Because there are no studies assessing the efficacy and safety of localized microinjection of tranexamic acid (TA) for the treatment of melasma, we conducted a pilot study to evaluate the efficacy and side effects of this potentially new method for the treatment of melasma in Korean women.A total of 100 women with melasma, after written consent, were enrolled for a prospective open pilot study of 12 weeks. After applying topical anesthesia, 0.05 mL TA (4 mg/mL) was injected intradermally into the melasma lesion at 1 cm intervals by using a 0.5 mL insulin syringe with a 30-gauge needle. This was repeated weekly for 12 weeks. A clinical investigator evaluated the results by using the Melasma Area and Severity Index (MASI) at baseline and at 4, 8, and 12 weeks. The patient satisfaction questionnaire was documented at 12 weeks. Safety evaluations were performed at each follow-up visit.Eighty-five patients completed the trial. A significant decrease in the MASI from baseline to 8 and 12 weeks was observed (13.22+/-3.02 vs 9.02+/-2.62 at week 8 and vs. 7.57+/-2.54 at week 12; p<.05 for both). The patients' self-assessment of melasma improvement was as follows: 8 of 85 patients (9.4%) rated as good (51-75% lightening), 65 patients (76.5%) as fair (26-50% lightening), and 12 patients (14.1%) as poor (0-25% lightening). Side effects were minimal and all the patients tolerated the treatment well.Based on these results, we suggest that the intralesional localized microinjection of TA acid can be used as a potentially new, effective, and safe therapeutic modality for the treatment of melasma.