Efficacy of oral tranexemic acid in refractory melasma: A clinico-immuno-histopathological study.

Tranexamic acid (TXA), a plasmin inhibitor, is an antifibrinolytic drug widely used to prevent and treat hemorrhage. We evaluated the effects of oral TXA clinically and immunohistopathologically in patients of refractory melasma. To evaluate the efficacy of oral TXA in patients with refractory melasma and correlate histopathological and immunohistochemical changes in pretreatment and post-treatment skin biopsies in patients willing to undergo biopsy. Thirty patients with refractory melasma were treated with oral TXA 500 mg twice daily along with a sunscreen and followed up. Modified MASI score (MMASI) and melasma quality of life (MELASQOL) were noted at baseline and after treatment. In patients willing to undergo skin biopsy, a 2 mm punch biopsy was obtained for histopathology and immunohistochemistry examination both before and after treatment with TXA. Clinical, histopathological, and immunohistochemical parameters were compared and correlated. Clinical improvement in melasma correlated in a perfect linear relationship with quality of life, decrease in epidermal pigmentation and decrease in Melan A staining on immunohistochemistry. Based on our observations, TXA can be said to have an inhibitory action on melanin synthesis and melanocyte proliferation. Future studies are required to further characterize the effects of TXA on the histopathology and immunohistochemistry of melasma, to standardize dosing schedule, duration of treatment and long term outcome, of which there are no definitive guidelines at present.