Excessive skin pigmentation is a result of abnormal production and deposition of melanin by the melanocytes. Melanocytes are the pigment-producing cells in our skin. The number of melanocytes present in our skin will determine our skin colour. Production of melanin is dependent on UV or sun exposure, and the natural protectiveness of the skin.
Hyperpigmentation, are areas that are darker than the rest of the skin.
Excess skin pigmentation is usually caused by an overproduction of the melanin-protective system. This leads to excess clumping of melanin, and the appearance of brown or darker spots of pigmentation in the skin.
Reasons for skin pigmentation are -
UV radiation – in most cases, especially when UV rays are at its highest, skin pigmentation problems can be caused by excessive UV or sun exposure.
Hormonal – as seen in melasma or chloasma, that is a type of pigmentation usually caused by pregnancy or birth control.
Trauma to the skin – this is a result of physical trauma to the skin, chemical peels, laser treatments and acne.
Birthmarks – Is a skin pigmentation that is present at birth and appear through childhood and adulthood.
Skin pigmentation is generally categorised into the following:
Epidermal (superficial) pigmentation – these pigmentation types are usually close to the outer layer of the skin and are induced by sun exposure and can include freckles.
Dermal (deep) pigmentation – these pigmentation types are usually found in the dermal layers.
Mixed dermal/epidermal pigmentation – These pigmentation types navigate through both the superficial and deeper layers of the skin. Melasma is an example of this.