Pigmentation

Excessive skin pigmentation is a result of abnormal production and deposition of melanin by the melanocytes. Melanocytes are pigment-producing cells. The number of melanocytes present in our skin will determine our skin colour. Production of melanin is dependent on UV or sun exposure, and is a natural protective mechanism of the skin.

Excess skin pigmentation or hyperpigmentation is usually caused by an overwhelming of the melanin-protective system. This leads to excess production and clumping of melanin, and the appearance of brown or darker spots of pigmentation in the skin.

Reasons for skin pigmentation problems are;

• UV radiation - in most cases, especially in areas of high UV radiation levels like Australia, skin pigmentation problems can be caused by excessive UV or sun exposure (most common)
• Hormonal - as seen in melasma or chloasma that is a type of pigmentation usually caused by pregnancy or the pill (common)
• Trauma to the skin - this can be a result of physical trauma to the skin, chemical peels, laser treatments, or acne. This is known as post-inflammatory hyperpigmentation (common).
• Birthmarks and acquired pigmentation - skin pigmentation can be present at birth (birthmarks), appear in childhood, or adulthood

Some lasers can be used for the treatment of skin pigmentation and have minimal or no impact on normal skin. This is possible due to the process of selective photothermolysis. This is a term that describes how a particular laser wavelength is attracted to pigmented lesions, and only minimally to the normal skin to allow selective removal of a lesion. This allows the laser to selectively disrupt the pigment with minimal or no damage to surrounding skin. Generally, the wavelengths that are attracted to the melanin in pigmented lesions range from 532 nanometers(nm) to 1064nm.