Hyper-pigmentation of the skin of the face.  Usually associated with pregnancy called the “mask of pregnancy”.  Thus hormonal fluctuation is generally understood to be a contributing factor in why Melasma happens.  Can also occur on Asian and hispanic skin that has been irritated to much and too often called Post traumatic hyper-pigmentation (PIH)  If sufficient PIH spots are present, individual spots might coalesce and become a larger “Melasma”