Hyperpigmentation (dark skin areas) is characterized by an increased production and accumulation of melanins or an increased number of melanocytes. Melanins are dark colored pigments produced by special skin cells, called melanocytes.
Hyperpigmentation can be inherited or, more often,
aquired by a number of causes including photoaging, hormonal changes (contraceptives, pregnancy, menopause), repeated and prolonged
exposure to the sun, and chronic skin irriations, inflammation or skin diseases.
Dark skin areas may be of cosmetic relevance especially if they occur in the face or other uncovered body areas. Many efforts have been devoted
to screening and testing recognized and putative
depigmenting agents. In addition, physical therapies, such as lasers, are currently under investigation to treat hyperpigmentation.
Skin may appear darker than normal and may be blotchy, uneven areas, or patches of brown to gray discoloration or freckling. Skin pigmentation disorders occur because the body produces either too much or too little melanin, a pigment produced by melanocytes.
Increased melanin production, also known as hyperpigmentation, is often referred to as melasma (general term describing darkening of the skin), chloasma (discolorations caused by hormones) or solar lentigines (darkened spots on the skin caused by the sun).
In addition, hyperpigmentation can be caused by skin damage, such as remnants of blemishes, wounds or rashes.
Skin-lighteners (like bearberry leaves extract and undecylenoyl phenylalanine) inhibit melanin tyrosinase or melanotropin and reduce or block some amount of melanin production.
Many treatments use a combination of topical lotions or gels containing melanin-inhibiting ingredients along with a sunscreen, and a prescription retinoid. Depending on how the skin responds to these treatments exfoliants, either in the form of topical cosmetic or chemical peels, and lasers may be used.