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This is an accepted version of this page This is the latest accepted revision, reviewed on 11 February 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 ...
People with this IB variant of the disorder commonly have white hair and skin at birth, but rapidly develop normal skin pigmentation in infancy. [56] Ocular albinism affects not only eye pigmentation but visual acuity, as well. People with albinism typically test poorly, within the 20/60 to 20/400 range.
Human skin pigmentation varies substantially between populations; this has led to the classification of people(s) on the basis of skin colour. [ 3 ] In terms of surface area, the skin is the second largest organ in the human body (the inside of the small intestine is 15 to 20 times larger).
Melanin is a dark pigment primarily responsible for skin color. Once synthesized, melanin is contained in special organelles called melanosomes which can be transported to nearby keratinocytes to induce pigmentation. Thus darker skin tones have more melanosomes present than lighter skin tones.
The Fitzpatrick scale has been criticized for its Eurocentric bias and insufficient representation of global skin color diversity. [9] The scale originally was developed for classifying "white skin" in response to solar radiation, [2] and initially included only four categories focused on white skin, with "brown" and "black" skin types (V and VI) added as an afterthought.
Epidermal nevi, neoplasms, and cysts are skin lesions that develop from the epidermal layer of the skin. [8] [26] Aberrant basal cell carcinoma; Acanthoma fissuratum (granuloma fissuratum, spectacle frame acanthoma) Acrospiroma (clear cell hidradenoma, dermal duct tumor, hidroacanthoma simplex, nodular hidradenoma, poroma)
Melanocytes and basal cells are embedded in the epidermal layer. Upon exposure to UVB rays, melanocytes will produce more melanin , a pigment that gives skin its color. UVB can cause the formation of freckles and dark spots, both of which are symptoms of photoaging; these are most common in people with fair or light skin. [ 7 ]
The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and hypodermis. [1] The epidermal layer provides a barrier to infection from environmental pathogens [2] and regulates the amount of water released from the body into the atmosphere through transepidermal water loss.