Tuesday, December 30, 2008

Pigmentation Disorders

Skin color is determined by a combination of pigments produced in the skin and natural colors of the external layers of the same. Without pigmentation, skin color would have a pale white with various ranges of pink, due to blood flowing through it. The main pigment of the skin is melanin, a dark brown pigment formed by cells (melanocytes) distributed among the other cells in the upper layer of skin, the epidermis.

The hypopigmentation, an abnormally low amount of pigment, it is generally restricted to small areas of skin. Usually stems from an inflammatory process prior to the skin or in exceptional cases may represent an inherited disease.

When skin is exposed to solar radiation increases the production of melanin and this produces the tan. An increase in the amount of melanin (hyperpigmentation) may be a response to hormonal abnormalities, such as those that may take place in Addison's disease during pregnancy or with use of oral contraceptives. The skin may also darken in diseases such as hemochromatosis or haemosiderosis, or as a response to many medications that are applied to the skin, are ingested or injected.


The albinism is a rare hereditary disease in which no melanin is formed.

People with albinism (albino) may have white hair, pale skin and pink eyes. Often, they can also present abnormal vision and involuntary eye movements (nystagmus).

Because the melanin protects the skin from the sun, albinos are very prone to sunburn and, consequently, to skin cancers. However, they can minimize these problems away from direct sunlight, using sunglasses and apply a sunscreen with a protection factor (SPF) increased from 15 in the parts of your skin.

Lack of pigmentation in the skin.


The vitiligo is a disease in which the loss of melanocytes produce smooth and white plates in the skin.

In some people are only one or two well-defined plaques, in other, the sheets of vitiligo appear on a large part of the body. The changes are more showy in people of darker pigmentation. As with albinism, non-pigmented skin is extremely sensitive to sunburn. The areas of skin affected by vitiligo also produce white hair, because hair follicles lose melanocytes.

The vitiligo may occur after a rare physical trauma, especially trauma to the head, and tends to concur with certain diseases, such as Addison's disease, diabetes, pernicious anemia and thyroid disease. The vitiligo can be psychologically devastating because of the great disfigurement that occurs after the change in pigmentation.

Pityriasis versicolor is a fungal infection of the skin that may resemble the vitiligo, although sometimes produces hyperpigmentation.


There is no known cure for vitiligo. Small areas can hide with different dyes that do not soiled clothes and whose effects last for several days. On occasion, treatment with psoralens (photosensitive drugs) combined with ultraviolet A (PUVA) is effective, but treatment requires time and must be continued indefinitely. The sunscreens and protective against exposure to sunlight can prevent burns.

Loss of pigment after skin injury

Sometimes the skin loses its pigment once they are cured some skin diseases such as blisters, sores, burns and skin infections. In this case the skin is not as white as in the vitiligo and with the passage of time may reappear pigmentation cosmetics can hide this kind of stain skin.


The melasma appears on the face (usually on the forehead, cheeks, temples and jaws) as plates hyperpigmented dark brown, often well-delineated on both sides of the face so symmetrical.

The melasma appears mostly during pregnancy (pregnancy mask) but may also occur in women taking oral contraceptives. Darkening, usually disappears shortly after birth or the suspension of oral contraceptives.

People suffering from melasma can use sunscreens on the plates dark and avoid sun exposure to prevent the worsening of the disease. If applied regularly for a long time, some ointments that are sold without a prescription can clarify the plates dark.

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