Melasma is an acquired hypermelanosis skin disorder that commonly affects women than men. It is characterized by irregular light to dark brown macules occurring in the sun-exposed areas of the face, neck and arms.
It occurs most commonly with pregnancy and with the use of contraceptive pills.
Other factors implicated in the etiopathogenesis are photosensitizing medications, mild ovarian or thyroid dysfunction and certain cosmetics.
Solar and ultraviolet exposure is the most common important factor in its development.
While exposure to UV light remains the top risk factor for skin cancer, other variables, such as smoking, immunosuppression and hypertension, also contribute to keratinocyte carcinoma, especially in nonwhite persons, a recent study has found.