The skin is the body's largest organ and contains special pigment-making cells called melanocytes. There are a wide variety of conditions that can lead to problems or abnormalities in skin pigmentation. Skin pigmentation problems can result in too much pigment being made (hyperpigmentation) or little or no pigment (hypopigmentation).
Melasma
Melasma is a skin condition that can cause patches of tan or brown skin to appear on the face, particularly the cheeks, forehead, chin, nose and upper lip. This condition (which is also known as chloasma) is sometimes called "the mask of pregnancy" because of its tendency to affect pregnant women, though it can also be developed by men. It can also be caused by the use of hormonal birth control or estrogen supplementation (for the symptoms of menopause). It can be treated with prescription or over-the-counter skin care products, although the condition will often go away without treatment. Sunlight will make the condition worse, so patients with melasma should always wear sunscreen.
Vitiligo
Vitiligo is an autoimmune disease, which means it is caused by the immune system attacking the body's cells. In vitiligo, skin cells called melanocytes are attacked. Because the melanocytes make melanin, which is the skin's pigmentation molecule, patients with vitiligo tend to have white patches of skin, particularly around the eyes, the mouth, and on the backs of their hands. This condition is related to other immune problems, including diabetes, thyroid disorders and Addison's disease. Although vitiligo cannot be cured, it can be treated using light-sensitive dyes along with exposure to ultraviolet light.
Albinism
Another cause of abnormal skin pigmentation is albinism. This condition, which is inherited, results in melanin not being made, leading to a lack of pigment in the hair, skin and eyes. This disease typically occurs in Caucasians, though it can be present in patients of any race. Albinos should wear sunscreen at all times due to their increased risk of sunburn and skin cancer.
Skin Damage
Skin damage, whether from an infection, burns, blisters or any other type of trauma can also result in a loss of pigmentation around the skin. This hypopigmentation is usually only temporary, however, and can be cosmetically concealed.
