Skin Lighteners / Bleachers

Vitiligo

Vitiligo, or depigmentation of the skin, is a skin condition caused by destruction of melancocytes, which are the cells that produce the pigment melanin. This results in loss of skin colour and the appearance of patches of pale skin that can occur anywhere on the body. Vitiligo is thought to be an autoimmune condition, whereby the body destroys its own melanocytes and cannot be cured. However, creams containing a skin lightener are used to lighten the surrounding skin and thereby mask the existing depigmented patches. Monobenzone (monobenzyl ether of hydroquinone) works by causing free-radical formation in the skin and this causes destruction of remaining melanocytes. As melanin production decreases the areas of normal skin gradually lighten to match the patches of vitiliginous paler skin.

Skin discolouration

Melanin is produced by the melanocytes in the skin epidermis to protect the deeper layers of the skin from damage due to ultraviolet radiation. Increased production of melanin causes the skin colour to darken. Repeated exposure to the sun results in more melanin production and eventually this causes formation of liver spots also known as solar lentigine, which are visible signs of sun damage. Liver spots become more common as we age, known as age spots or senile lentigine, and are more frequent in parts of the body receiving the most sun exposure, like the face, forearms and shoulders. Freckles are similar to sun spots and are caused by areas of concentrated melanin production, triggered by sun exposure. They are usually related to a genetic predisposition and associated with fair skin.

Another form of skin discolouration, melasma or chloasma has a genetic predisposition and is more common in women. Melasma is triggered by sun exposure, hormonal treatments like contraceptives and HRT, pregnancy and thyroid disease. These patches of increased pigmentation appear on the face and are also caused by overproduction of melanin. Skin discolouration can also be caused by scar formation, such as acne scars.

Lightening the skin

A cream containing hydroquinone is used to lighten patches of skin discolouration such as age spots, sun spots, freckles and acne scars. It works by Inhibiting tyrosinase, an enzyme involved in the production of melanin, which decreased the amount of melanin produced, as well as increasing the breakdown of melanosomes in melanocytes that contain the melanin. This action gradually causes the skin to lighten and match the surrounding normal skin colour.