Melasma is a chronic and relapsing acquired dyschromia due to an increased epidermal-melanin unit activity that affects sun-exposed areas mainly in women throughout the reproductive years. It is more common in women, accounting for 90% of all cases.The majority of patients are in third and fourth decades of their life. There are several risk factors that influence its appearance including genetic predisposition,exposure to heat and UV radiation, pregnancy, and exogenous hormones (such as oral contraceptives,thyroid hormones, and hormone replacement therapy). Other factors implicated are phototoxic drugs, anticonvulsant medications,and the use of certain cosmetics. Types of melasma are epidermal, dermal and mixed according to location of melanin.