Pigmentation is the coloring of a person's skin. When a person is healthy, their skin color will appear normal. In the case of illness or injury, the person's skin may change color, becoming darker (hyperpigmentation) or lighter (hypopigmentation).
Hyperpigmentation and Skin
Hyperpigmentation in skin is caused by an increase in melanin, the substance in the body that is responsible for color (pigment). Certain conditions, such as pregnancy or Addison's disease (decreased function of the adrenal gland), may cause a greater production of melanin and hyperpigmentation. Exposure to sunlight is a major cause of hyperpigmentation, and will darken already hyperpigmented areas.
Hyperpigmentation can also be caused by various drugs, including some antibiotics, antiarrhythmics, and antimalarial drugs.
An example of hyperpigmentation is melasma. This condition is characterized by tan or brown patches, most commonly on the face. Melasma can occur in pregnant women and is often called the "mask of pregnancy;" however, men can also develop this condition. Melasma sometimes goes away after pregnancy. It can also be treated with certain prescription creams (such as hydroquinone).
If you have melasma, try to limit your exposure to daylight. Wear a broad-brimmed hat and use a sunscreen with an SPF of 30 or higher at all times, because sunlight will worsen your condition. Sunscreens containing the physical blockers zinc oxide or titanium dioxide are also helpful in blocking daylight’s UVA rays, which makes hyperpigmentation worse. People with darker skin are at higher risk for melasma. It will look like dark brown or greyish brown patches on darker skin.
Consult with your doctor before treating the condition yourself.
Hypopigmentation and Skin
Hypopigmentation in skin is the result of a reduction in melanin production. Examples of hypopigmentation include:
- Vitiligo: Vitiligo causes smooth, white patches on the skin. In some people, these patches can appear all over the body. It is an autoimmune disorder in which the pigment-producing cells are damaged. There is no cure for vitiligo, but there are several treatments, including cosmetic cover-ups, corticosteroid creams, calcineurin inhibitors (Elidel cream, Protopic ointment) or ultraviolet light treatments. The Janus Kinase inhibitor ruxolitinib (Opzelura) has been approved for the treatment of nonsegmental vitiligo in adult and pediatric patients 12 years of age and older.
- Albinism: Albinism is a rare inherited disorder caused by the absence of an enzyme that produces melanin. This results in a complete lack of pigmentation in skin, hair, and eyes. Albinos have an abnormal gene that restricts the body from producing melanin. There is no cure for albinism. People with albinism should use a sunscreen at all times because they are much more likely to get sun damage and skin cancer. This disorder can occur in any race, but is most common among whites.
- Pigmentation loss as a result of skin damage: If you've had a skin infection, blisters, burns, or other trauma to your skin, you may have a loss of pigmentation in the affected area. The good news with this type of pigment loss is that it's frequently not permanent, but it may take a long time to re-pigment. Cosmetics can be used to cover the area, while the body regenerates the pigment.