Hyperpigmentation is the process of darkening of a skin or nail area caused by the increased presence of melanin in it.
It can be congenital (like café au lait, nevus of ota, and others) or acquired (caused by sun damage, inflammation, or other skin injuries, including those related to acne vulgaris). People with darker Asian, Mediterranean, or African skin tones are also more prone to it, especially if they have excessive sun exposure.
Many forms of hyperpigmentation are caused by an excessive production of melanin. It can be diffuse or focal, affecting such areas as the face and the back of the hands.
Melanin is a class of pigment produced by melanocytes at the lower layer of the epidermis and is responsible for producing coloration in the body, in places such as the eyes, skin and hair. As the body ages, melanocyte distribution becomes less diffuse and its regulation less controlled by the body. UV light stimulates melanocyte activity, and where concentrations of the cells are denser than surrounding areas, hyperpigmentation is affected. Hyperpigmentation can also be caused by using skin lightening lotions.
Another form of hyperpigmentation is post inflammatory hyperpigmentation. These are dark and discolored spots that appear on your skin following acne that has healed
Treatment of hyperpigmentation includes treating the possible cause of its occurrence: