The Factors Affecting Skin Colour
There are 3 main elements that contribute to the colour of the skin. They are:
Melanin – melanocytes (melanin cells) are responsible for creating pigment that helps protect the dermis by filtering UV radiation. Melanin is also the pigment that gives skin its colour. Melanin is found in the basal layer of the epidermis.
All humans have approximately the same amount of melanin in their skin. Skin colour varies due to the differences in the amount of melanin that the melanocytes (melanin cells) produce.
When there is a failure of the melancytes to produce and pigment the individual concerned is affected by a condition called Albinism. Partial lack of pigment results in white spots known as Vitiligo. Freckles result from the production of melanin in small areas.
Melanin production is stimulated by UV radiation. The melanin is taken up by the epidermal cells and distributed through the skin. Continual exposure to UV radiation then produces increased amounts of melanin resulting in a tan.
Carotene – is another pigment found in the stratum corneum and other areas of the dermis in Asiatic races. Carotene and melanin combine to form a yellow undertone to the skin.
Blood – in the capillaries of the dermis combines with the lowered levels of pigmentation contributing to the pinkish hue of Caucasian skin.
Skin exhibits four main colours – red, yellow, blue and brown. Haemoglobin in red blood cells generates the red (pink) tones. Yellow colours are generated from carotene levels. When oxygen is replaced with carbon dioxide carried in veins they appear blue. Brown pigment makes up the fourth tone found in melanin.
Skin colour can also be affected by other factors such as absorption and reflection of light, use of lightening and darkening products, use of artificial radiation. Skin pigmentation and pigmentation disorders are particularly relevant to therapists as most people have a desire to even their skin tone.