What causes vitiligo?

There are many theories about what causes vitiligo, and no one is positively certain. However, many doctors and researchers believe that a genetic predisposition or susceptibility to vitiligo exists in most people who develop vitiligo.

Vitiligo may result from a number of factors -- autoimmune, oxidative stress (excess of hydrogen peroxide), neurotrophic (interaction of melanocytes and the nervous system), and toxic (substances formed as a part of normal melanin production actually being toxic to melanocytes) hypotheses have been advanced. The mechanism involves progressive destruction of selected melanocytes, probably by cytotoxic T-cell lymphocytes.

Many believe that vitiligo is a type of autoimmune disorder, in which the body's immune system sees the pigment cells in the skin as foreign bodies, and attacks them. The basis for this autoimmune disorder is believed by many to be genetic. Stress, traumatic events, injury, or severe sunburns, may trigger or exacerbate vitiligo in those who are susceptible, though this has not been substantiated.

Other theories include the possibility that an abnormally functioning nervous system may produce a substance that injures melanocytes. Some believe that melanocytes in vitiligo patients may self-destruct, releasing toxic byproducts that then destroy other pigment cells. Another theory suggests that vitiligo is entirely genetic, and that there is a defect in the melanocytes that makes them more susceptible to injury.

We know that some cases of vitiligo arise from exposure to certain chemicals, for example, phenols used in photography. Surgery wounds or injuries to the skin have also been known to result in vitiligo, which can spread. The question is, are those people susceptible to vitiligo to begin with. Many experts say yes.

Finally, there are alternative theories about vitiligo that suggest diet, nutrition, and digestive disorders may play a role in the destruction of melanocytes. Some believe that internal pathogens within the digestive tract, such as yeast proliferation, might relate to vitiligo.

What is oxidative stress?

This is one theory about what may cause or contribute to the onset or exacerbation of vitiligo. Oxidative stress is an over-accumulation of hydrogen peroxide in the skin. Every person develops hydrogen peroxide in the skin, as a result of natural biological processes. An enzyme called "catalase" normally breaks down the hydrogen peroxide in the skin into water and oxygen. However, some people with vitiligo may have a problem manufacturing, using or delivering catalase to the skin.

Is it true that genetics may play a part in vitiligo?

Most experts believe that there is a genetic base to vitiligo which leads to susceptibility. In about 12% of families where a person has vitiligo, the condition is seen in another family member. Though no one else in your family may show signs of vitiligo, it is still possible that it is passed on genetically. The most likely reason for this is that more than one gene is responsible for the development of vitiligo. In fact, a combination of genes that may prove to be involved. In some cases, an independent stimulus may cause the condition to onset.

Genes are inherited in a random fashion from both parents, so only sometimes will the genes which make a person susceptible to vitiligo come together in the same person. Those who do not inherit a complete set of the abnormal genes are unlikely to develop the disorder. Those people who do inherit a complete set may also need some other factor to trigger the vitiligo patches to appear. In this way vitiligo genes can pass through several generations of a family without anyone actually developing vitiligo.

Currently, researchers are studying the genetic aspects of vitiligo, using gene-sequencing computers and the mapping of the human genome to determine how genetic therapy and technology might help treat or arrest vitiligo.

What is genetic susceptibility?

This is the theory that the susceptibility or predisposition to vitiligo is genetic, and that some defect in the genetic structure, makes people more susceptible to vitiligo. While we do see vitiligo in more than one family member about 20% of the time, about 80% of patients report no other family members with vitiligo. Many experts agree that not everyone who is susceptible to vitiligo will necessarily develop it. Recent genetic studies, which ran the DNA of hundreds of people with vitiligo through gene sequencing computers, have produced important information about the enzyme operations in the bodies of those with vitiligo, which may help researchers better understand how to treat the underlying cause of vitiligo.

As with all genes, people may carry the defect that causes vitiligo, and even pass it on to their children, without ever developing vitiligo themselves. Thus other factors, including environmental and personality factors, may play a role in the onset (beginning) of vitiligo.

Is it true that exposure to certain chemicals can cause vitiligo?

Some chemicals, particularly photography chemicals such as Phenols, can trigger vitiligo in those who are susceptible. Phenols can also be found in many types of hair colorings, household stains, and similar products. There are other industrial chemicals and substances which may also trigger the onset of vitiligo.

Are there things that a person with vitiligo should avoid?

In addition to the phenol type chemicals listed in the previous paragraph, there are other things and activities which people with vitiligo should avoid. Unfortunately, the list of activities, products and chemicals to avoid varies, depending on who you talk to. Our Main Message Board has numerous topics about this subject, however, we will be updating this section shortly, with a list of some of the things many people agree may make vitiligo worse.

Are there any other symptoms? Will Vitiligo lead to other conditions or diseases?

Other than the white patches of skin, there are no other physical symptoms of vitiligo. As a secondary effect, vitiligo patches will tend to sunburn more easily, and sunscreen is often recommended. Though some websites suggest eye color and vision may be affected by vitiligo, experts indicate that any effect on eye color or the retinal pigment is extremely rare, and any impairment of vision, even rarer.

Are there other conditions related to vitiligo?

Vitiligo in of itself does not appear to "lead" to other conditions. However, there are other autoimmune-related conditions, which may arise in vitiligo patients, and that may even arise from the same genetic disorder that results in vitiligo.

Thyroid disorders (especially hypothyroidism) are quite common in those with vitiligo, and many doctors feel treating thyroid disorders is important in treating vitiligo. Other related autoimmune conditions are much rarer, but include alopecia areata, pernicious anemia, lupus, and occasionally diabetes. To worry that these other conditions will arise is unwarranted, as they are not very common. But understanding these other conditions, and knowing about their symptoms, may be wise.

Nevertheless, most people with vitiligo have no other autoimmune disorders.

How is thyroid function related to vitiligo?

Thyroid disorders are extremely common in every ethnic and racial group on the planet.

The thyroid is a small, butterfly-shaped gland just below the Adam's apple. This gland plays an important role in controlling the body's metabolism, that is, how the body functions. It does this by producing thyroid hormones (T4 and T3), chemicals that travel through the blood to every part of the body. Thyroid hormones tell the body how fast to work and use energy.

Because vitiligo may well be related to numerous functions within the body, a properly functioning thyroid (or sufficient supplemental hormone) could be important in treating vitiligo.

What is alopecia areata?

Alopecia areata is a fairly common condition (ranking with vitiligo) that results in the loss of hair on the scalp and elsewhere. It usually starts with one or more small, round, smooth patches. It occurs in males and females of all ages, but onset most often occurs in childhood. In alopecia areata, the affected hair follicles become very small, drastically slow down production, and grow no hair visible above the surface for months or years. It is not the same as male pattern baldness, which is a much more common genetic condition in males.

Current research suggests that something triggers the immune system to suppress the hair follicle. Recent research indicates that some persons have genetic markers that may increase their susceptibility to develop alopecia areata. Some believe alopecia may be one of vitiligo's closest relatives, because of the autoimmune nature of the condition. However, only a very small percentage of people with vitiligo also develop alopecia areata. Alopecia areata may result in symptoms (skin pigment loss) which appear similar to vitiligo, and some vitiligo patients are initially diagnosed with alopecia. However, proper medical examination can determine which condition is present.