Background and Objectives: Melasma is an acquired hyperpigmentary disorder mainly on the face. Tranexamic acid (TA), a plasmin inhibitor, has been suggested as an efficient treatment modality on melasma. The aim of this study was to investigate the effects and action mechanism of topical TA in the treatment of melasma.
Material and methods: Twenty three healthy Korean females with melasma were enrolled, and applied 2% TA formulation on the whole face for 12 weeks. Pigmentation and erythema were objectively assessed using melasma severity scale (MSS), modified melasma area and severity index (mMASI), and chromameter. The subject satisfaction questionnaire was also documented. Skin biopsies were obtained from 10 subjects on baseline and 12 weeks after treatment. Histological and immunohistochemical analyses were performed.
Results: After 12 weeks, significant improvement in MSS and mMASI showed in 22 of 23 patients. L* values were increased in both lesional and perilesional normal skin after 12 weeks. The improvement was noticed in 4 weeks. a* values were decreased in both lesional and perilesional normal skin. Subjective satisfaction score was improved. Fontana-Masson staining showed significant decrease of pigmentation in both lesional and perilesional normal skin after treatment. There were no changes in vascularity and number of mast cells. ET-1 expression was significantly decreased in the epidermis of both lesional and perilesional normal skin after treatment. SCF expression in the epidermis was significantly decreased in the lesional skin after treatment. There were no changes in expressions of α-MSH, EP2, and VEGF.
Conclusion: Topical TA improved pigmentation and erythema in melasma. Decreased expression of ET-1 and SCF in the epidermis after treatment was suspected to be an action mechanism of topical TA for melasma treatment.
