Background and Introduction: A common pigmentary condition, melasma, is best defined as localized, chronic – acquired hyper melanosis of the skin characterized by light to dark brown macules and patches symmetrically involving the sun-exposed areas of the face, neck and occasionally the forearms. It is commonly observed in reproductive age group women, rarely in postmenopausal females and males (10% of cases). Causative factors implicated in the melisma pathogenesis include genetic susceptibility, ultraviolet (UV) light exposure, pregnancy, sex hormones, contraceptive pills, thyroid disease, cosmetics, phototoxic drugs (e.g., antiseizure medications).
(Grimes PE,1995)(Park et al,2017)There are three clinical patterns of melasma, malar (most common), centro facial and mandibular. On the basis of visible light, wood’s light and lesional histology, melasma has been classified as epidermal, which has increased melanin predominantly in basal and suprabasal layers of the epidermis with pigment accentuation on Wood’s lamp. The dermal type has perivascular melanin-laden macrophages in the superficial and deep dermis and does not accentuate with Wood’s lamp.
The mixed variety has elements of both and appears as deep brown colors with Wood’s lamp accentuation of only the epidermal component.(Sanchez NP et al,1981)Melasma is well known for treatment resistance and relapses on treatment discontinuation.Melasma is found to be refractory to treatment, with a tendency to recur after treatment. There is not a single satisfactory treatment modality to date.(Del Rosario E.
, et al, 2018) In melasma treatment, the introduction of tranexamic acid ( oral, topical or intralesional) is relatively a novel concept. The skin?whitening effects of TXA were incidentally found when it was used in the treatment of aneurysmal subarachnoid hemorrhage. Nijor from Japan,1979 first reported TXA to be effective in melasma treatment