Changes in melanin pigmentation, hypervascularization, pregnancy, inflammation, diet, growth of foreign organisms, diseases, cyanosis, hypercarotenemia, mineral overload, medicines and jaundice can cause these various hues of coloration.
Skin coloration with white or pale spots and patches
White patches and lightening of epidermis occurs due to hypopigmentation, wherein the melanin pigmentation gets reduced. This situation can be due to self destruction of melanin producing cells (melanocytes) in diseases like vitiligo.
Certain infections like tinea versicolor can affect the melanocytes and white patches can appear. Conditions like nevus depigmentosus, idiopathic guttate hypomelanosis, fordyce spots can also give rise to harmless white spots and patches.
Skin discoloration with dark/brown spots and patches
Dark/brown type of spots are due to hyperpigmentation caused by excessive production and deposition of melanin pigment by melanocytes (pigment producing cells).
Prolonged sun exposure, hormonal imbalances, diabetes, melasma, pregnancy and old age may be some of the reasons for this condition.
Reddish type of discoloration
- Reddening of the epidermis may be caused by infections, inflammation, rash, eczema, sunburn and dermatitis. Hypervascularization of the certain areas of the dermis also can cause reddening.
Blue type of skin coloration
- The dermis becomes bluish when the blood is low in oxygen (cyanosis). This type of coloration can be observed in young children when the weather gets very cold. This is due to slowing down of circulation in the blood vessels in the dermis. In case of lung infections and impaired heart functions the oxygen level may go down resulting in blueness of epidermis.
Yellow type of skin
In case of jaundice, mucus membranes, eyes and epidermis become yellow due to the presence of bilirubin.
Bilirubin is the yellow pigment (a product of RBC breakdown) present in bile and when the bile is obstructed from reaching the gastrointestinal canal, it gets into circulation.
Bronze or slate-grey skin pigmentation
- When there is iron overload or iron poisoning the epidermis may appear slate-grey or bronze in color. This type of coloration is a grave situation and necessary medical treatments must be given to avoid greater damages.
Orange skin coloration
- When epidermis accumulates carotenoids, it appears yellowish orange in color. Carotenoderma occurs when fruits and vegetables containing carotene is consumed in excess. This is a harmless condition resolving by itself when the carotene consumption is brought down.