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Melanocytes are melanin-producing neural crest-derived [3] cells located in the bottom layer (the stratum basale) of the skin's epidermis, the middle layer of the eye (the uvea), [4] the inner ear, [5] vaginal epithelium, [6] meninges, [7] bones, [8] and heart found in many mammals and birds. [9] Melanin is a dark pigment primarily responsible ...
This is an accepted version of this page This is the latest accepted revision, reviewed on 28 January 2025. "Skin pigmentation" redirects here. For animal skin pigmentation, see Biological pigment. Extended Coloured family from South Africa showing some spectrum of human skin coloration Human skin color ranges from the darkest brown to the lightest hues. Differences in skin color among ...
Hyperpigmentation can be diffuse or focal, affecting such areas as the face and the back of the hands. Melanin is produced by melanocytes at the lower layer of the epidermis . Melanin is a class of pigment responsible for producing color in the body in places such as the eyes, skin, and hair.
Phototoxicity, also called photoirritation, is a chemically induced skin irritation, requiring light, that does not involve the immune system. [1] It is a type of photosensitivity. [1] [2] The skin response resembles an exaggerated sunburn.
Acanthosis nigricans is a medical sign characterised by brown-to-black, poorly defined, velvety hyperpigmentation of the skin. [1] It is usually found in body folds, [2] such as the posterior and lateral folds of the neck, the armpits, groin, navel, forehead and other areas.
[1] Melanism is the congenital excess of melanin in an organism resulting in dark pigment . Pseudomelanism, also called abundism, is another variant of pigmentation, identifiable by dark spots or enlarged stripes, which cover a large part of the body of the animal, making it appear melanistic.
Melasma (also known as chloasma faciei, [1]: 854 or the mask of pregnancy [2] when present in pregnant women) is a tan or dark skin discoloration.Melasma is thought to be caused by sun exposure, genetic predisposition, hormone changes, and skin irritation. [3]
Freckles are clusters of concentrated melaninized cells which are most easily visible on people with a fair complexion.Freckles do not have an increased number of the melanin-producing cells, or melanocytes, but instead have melanocytes that overproduce melanin granules (melanosomes) changing the coloration of the outer skin cells (keratinocytes).