The term discoloration refers to an alteration of the colour of the skin due to excess of melanin or, in some cases, to the deposit of pigments of a different nature, for example derived from haemoglobin or of exogenous origin, on the epidermis. This alteration may be localized in a specific part of the body, or spread.
In the case of melanin, two types of discoloration are possible: hyperchromia and hypochromia.
Hyperchromia takes place when there is an increase in pigmentation, such as in the case of freckles, melasma and ephelides.
On the contrary, hypochromia takes place when the pigment is absent, such as in the case of vitiligo and albinism.
Melanin is a pigment produced by melanocytes, cells found in the skin, which gives colour to the skin and is produced by the body in different quantities, depending on the different ethnic groups. When the production of melanin undergoes changes, skin discoloration takes place.
Discoloration or skin spots may occur to anyone, although the skin type and tone may affect it.
The main cause of skin discoloration or spots is solar radiation. Damage due to exposure to the sun may, in fact, take decades before be outwardly visible; therefore, even if there are no immediate problems, it is always better to apply a protective filter when exposing the skin to the sun.