What is the Origin of Melasma?

The term originates from the Greek word melas, meaning "black," directly referring to the dark pigmentation of the lesions. Its clinical recognition as a "mask of pregnancy" solidified its association with the systemic hormonal environment.

What is the Mechanism of Melasma?

The pathogenesis of melasma is fundamentally driven by the synergistic action of hormonal stimulation and ultraviolet radiation exposure on melanocytes. Estrogen and progesterone receptors are present on melanocytes, and elevated levels of these sex hormones, such as during pregnancy or with oral contraceptive use, increase the expression of key melanogenic enzymes like tyrosinase. This hormonal signaling pathway amplifies the melanocyte's response to UV light, leading to persistent, localized overproduction of melanin and the characteristic hyperpigmented macules.

Melasma ∞ Area

Melasma

Meaning

Melasma is a common, chronic acquired disorder of hyperpigmentation characterized by symmetric, blotchy, light to dark brown patches predominantly appearing on sun-exposed areas of the face, such as the cheeks, forehead, and upper lip. This dermatological condition is histologically defined by the overproduction and deposition of melanin by hyperactive melanocytes within the epidermis and/or dermis. It is a cosmetically significant condition with a strong and recognized link to hormonal fluctuations.