The clinical feature of melasma is described as an acquired symmetrical hyperpigmentation occurring in exclusively photo-exposed areas, commonly on the face. Other sun-exposed areas such as the extensors of the forearms and upper mid-chest may also be involved. It is most common in women but may occur in men in about 10 % of cases [5, 6]. This hyperpigmentation varies from light to dark brown or brown-gray patches with irregular borders which may coalesce in a reticular pattern. On closer look, one notices some areas to be more homogenous or darker in tone in contrast to other areas. This detail, together with percentage involvement, is an important point of reference when doing clinical research in melasma.
Melasma is commonly referred to as “chloasma” or the “mask of pregnancy.” The name is derived from the Latin word “chloos” and the Greek “cloazein” to mean green and “melas” to mean black. Areas of hypermelanosis tend to disappear or diminish after parturition, but in brown or darker skin tone, this may persist for long periods of time .