Melasma is a skin condition defined by the appearance of dark, irregular patches on the face, typically on the forehead, cheeks, upper lip and chin. The main contributing factors are genetic predisposition, hormonal changes (for example during pregnancy or with certain contraceptives) and sun exposure, especially without adequate protection.
Prevention relies on consistent high-SPF photoprotection, with sunscreen reapplied several times a day, combined with hats and sunglasses, and, when medically appropriate, on adjusting or suspending photosensitising medications before direct sun exposure.