What is vitiligo, and what causes it?
(DR.MUHAMMAD MANSOOR-UL-HAQ)
Vitiligo (vit-ill-EYE-go) is apigmentation disorder in which melanocytes (the cells that make pigment) in the skin are destroyed. As a result, white patches appear on the skin in different parts of the body. Similar patches also appear on both the mucous membranes (tissues that line the inside of the mouth and nose), and the retina (inner layer of the eyeball). The hair that grows on areas affected by vitiligo sometimes turns white.
The cause of vitiligo is not known, but doctors and researchers have several different theories. There is strong evidence that people with vitiligo inherit a group of three genes that make them susceptible to depigmentation. The most widely accepted view is that the depigmentation occurs because vitiligo is an autoimmune disease -- a disease in which a person's immune system reacts against the body's own organs or tissues. As such, people's bodies produce proteins called cytokines that alter their pigment-producing cells and cause these cells to die. Another theory is that melanocytes destroy themselves. Finally, some people have reported that a single event such as sunburn or emotional distress triggered vitiligo; however, these events have not been scientifically proven as causes of vitiligo.
Who is affected by vitiligo?
About 0.5 to 1 percent of the world's population, or as many as 65 million people, have vitiligo. In the United States, 1 to 2 million people have the disorder. Half the people who have vitiligo develop it before age 20; most develop it before their 40th birthday. The disorder affects both sexes and all races equally; however, it is more noticeable in people with dark skin.
Vitiligo seems to be somewhat more common in people with certain autoimmune diseases. These autoimmune diseases include hyperthyroidism (an overactive thyroid gland), adrenocortical insufficiency (the adrenal gland does not produce enough of the hormone called corticosteroid), alopecia areata (patches of baldness), and pernicious anemia (a low level of red blood cells caused by the failure of the body to absorb vitamin B12). Scientists do not know the reason for the association between vitiligo and these autoimmune diseases. However, most people with vitiligo have no other autoimmune disease.
Vitiligo may also be hereditary; that is, it can run in families. Children whose parents have the disorder are more likely to develop vitiligo. In fact, 30 percent of people with vitiligo have a family member with the disease. However, only 5 to 7 percent of children will get vitiligo even if a parent has it, and most people with vitiligo do not have a family history of the disorder.
What are the symptoms vitiligo?
People who develop vitiligo usually first notice white patches (depigmentation) on their skin. These patches are more commonly found on sun-exposed areas of the body, including the hands, feet, arms, face, and lips. Other common areas for white patches to appear are the armpits and groin, and around the mouth, eyes, nostrils, navel, genitals, and rectum.
Vitiligo generally appears in one of three patterns:
1. focal pattern -- the depigmentation is limited to one or only a few areas
2. segmental pattern -- depigmented patches develop on only one side of the body
3. generalized pattern -- the most common pattern. Depigmentation occurs symmetrically on both sides of the body.
In addition to white patches on the skin, people with vitiligo may have premature graying of the scalp hair, eyelashes, eyebrows, and beard. People with dark skin may notice a loss of color inside their mouths.
Will the depigmented patches spread?
Focal pattern vitiligo and segmental vitiligo remain localized to one part of the body and do not spread. There is no way to predict if generalized vitiligo will spread. For some people, the depigmented patches do not spread. The disorder is usually progressive, however, and over time the white patches will spread to other areas of the body. For some people, vitiligo spreads slowly, over many years. For other people, spreading occurs rapidly. Some people have reported additional depigmentation following periods of physical or emotional stress.
The diagnosis of vitiligo is made based on a physical examination, medical history, and laboratory tests.
A doctor will likely suspect vitiligo if you report (or the physical examination reveals) white patches of skin on the body-particularly on sun-exposed areas, including the hands, feet, arms, face, and lips. If vitiligo is suspected, the doctor will ask about your medical history. Important factors in the diagnosis include a family history of vitiligo; a rash, sunburn, or other skin trauma at the site of vitiligo 2 to 3 months before depigmentation started; stress or physical illness; and premature (before age 35) graying of the hair. In addition, the doctor will ask whether you or anyone in your family has had any autoimmune diseases, and whether you are very sensitive to the sun.
To help confirm the diagnosis, the doctor may take a small sample (biopsy) of the affected skin to examine under a microscope. In vitiligo, the skin sample will usually show a complete absence of pigment-producing melanocytes. On the other hand, the presence of inflamed cells in the sample may suggest that another condition is responsible for the loss of pigmentation.
Because vitiligo may be associated with pernicious anemia (a condition in which an insufficient amount of vitamin B12 is absorbed from the gastrointestinal tract) orhyperthyroidism (an overactive thyroid gland), the doctor may also take a blood sample to check the blood-cell count and thyroid function. For some patients, the doctor may recommend an eye examination to check for uveitis (inflammation of part of the eye), which sometimes occurs with vitiligo. A blood test to look for the presence of antinuclear antibodies (a type of autoantibody) may also be done. This test helps determine if the patient has another autoimmune disease.
How can people cope with the emotional and psychological aspects of vitiligo?
While vitiligo is usually not harmful medically, its emotional and psychological effects can be devastating. In fact, in India, women with the disease are sometimes discriminated against in marriage. Developing vitiligo after marriage can be grounds for divorce.
Regardless of a person's race and culture, white patches of vitiligo can affect emotional and psychological well-being and self-esteem. People with vitiligo can experience emotional stress, particularly if the condition develops on visible areas of the body, such as the face, hands, arms, and feet; or on the genitals. Adolescents, who are often particularly concerned about their appearance, can be devastated by widespread vitiligo. Some people who have vitiligo feel embarrassed, ashamed, depressed, or worried about how others will react.
Fortunately, there are several strategies to help people cope with vitiligo. Also, various treatments-which we will discuss a bit later-can minimize, camouflage, or, in some cases, even eliminate white patches. First, it is important to find a doctor who is knowledgeable about the disorder and takes it seriously. The doctor should also be a good listener and be able to provide emotional support. You must let your doctor know if you are feeling depressed, because doctors and other mental health professionals can help people deal with depression. You should also learn as much as possible about the disorder and treatment choices so that you can participate in making important decisions about medical care.
Talking with other people who have vitiligo may also help. The National Vitiligo Foundation can provide information about vitiligo and refer you to local chapters that have support groups of patients, families, and physicians. Contact information for the foundation is listed at the end of this brochure. Family and friends are another source of support.
Some people with vitiligo have found that cosmetics that cover the white patches improve their appearance and help them feel better about themselves. You may need to experiment with several brands of concealing cosmetics before finding the product that works best.
