Causes of Vitiligo:
Various causes are attributed to the disease. some of the common ones are:
Hereditary
Vitiligo can run in families. Children whose parents have the disorder are more likely to develop Vitiligo. However most children will not get vitiligo even if a parent has it and most people with vitiligo do not have a family history of the disorder.
Auto-immunity
Healthy skin contains melanin, a brown pigment produced from the amino acid tyrosine by pigment cells (melanocytes) in the skin. Melanin is the pigment that determines the colour of skin, hair, and eyes. It is produced in cells called melanocytes. If melanocytes cannot form melanin or if their number decreases, skin colour will become progressively lighter. If skin affected by vitiligo is examined under the microscope, the melanocytes are absent and there are signs of inflammation in the deeper layer of the skin.
It is not known exactly why some people develop this condition and others do not. Some experts believe it is an autoimmune disorder (in which an individual's immune system reacts against part of their own body). In vitiligo, specific autoantibodies against a patient's melanocytes are found in the blood, although it is not known whether autoantibodies are the cause or an effect of the damage seen. There are many autoimmune disorders and some families are more prone to this group of conditions as a whole. Another explanation for vitiligo suggests it is due to a nerve disorder, because nerve damage has been associated with pigment loss in the area of skin served by the nerve.
There are certain auto-immune diseases which are associated with Vitiligo like:
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Hyper Thyroidism (Overactive Thyroid Gland). |
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Adrenocortical Insufficiency (Decrease in level of Hormone called corticosteriod). |
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Alopecia Aerate (Patches of Baldness).Pernicious Anaemia (a low level of Haemoglobin caused by the failure of the body to absorb Vitamin B12). |
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Diabetes Mellitus, Psoriasis. |
Segmental Vitiligo
Here the lesion spreads along the course of a particular nerve. It is thought that the nerve releases certain toxic substances which may destroy the melanocytes.
Chemical/Contact leukoderma
This occurs at the site of contact of certain chemicals like rubber gloves containing monobenzylether of hydroguinone, rubber condoms, bindis, brassiere, watch strap, surgeons gloves, rubber chappal straps.
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.
Healthy skin contains melanin, a brown pigment produced from the amino acid tyrosine by pigment cells (melanocytes) in the skin. Melanin is the pigment that determines the colour of skin, hair, and eyes. It is produced in cells called melanocytes. If melanocytes cannot form melanin or if their number decreases, skin colour will become progressively lighter. If skin affected by vitiligo is examined under the microscope, the melanocytes are absent and there are signs of inflammation in the deeper layer of the skin.
It is not known exactly why some people develop this condition and others do not. Some experts believe it is an autoimmune disorder (in which an individual's immune system reacts against part of their own body). In vitiligo, specific autoantibodies against a patient's melanocytes are found in the blood, although it is not known whether autoantibodies are the cause or an effect of the damage seen. There are many autoimmune disorders and some families are more prone to this group of conditions as a whole. Another explanation for vitiligo suggests it is due to a nerve disorder, because nerve damage has been associated with pigment loss in the area of skin served by the nerve.
The severity of vitiligo differs with each individual. Light skinned people usually notice the pigment loss during the summer as the contrast between the affected skin and sun tanned skin becomes more distinct. People with dark skin may observe the onset of vitiligo any time. In a severe case pigment may be lost from the entire body. The eyes do not change colour. There is no way to predict how much pigment an individual will lose. The degree of pigment loss can vary within each vitiligo patch which means that there may be different shades of brown in a vitiligo patch. This is called ‘trichrome’. A border of darker skin may circle an area of light skin. Vitiligo frequently begins with a rapid loss of pigment which may be followed by a lengthy period when the skin colour does not change. Later, the pigment loss may begin again. The loss of colour may continue until, for unknown reasons, the process stops. Cycles of pigment loss followed by periods of stability may continue indefinitely.
Vitiligo is equally common in men and women. It can appear at any age but 50 per cent of patients are under 20 when it first appears.
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.
Hereditary: 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.
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 rectal areas.
Vitiligo generally appears in one of three patterns:
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Focal pattern—the depigmentation is limited to one or only a few areas |
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Segmental pattern—depigmented patches develop on only one side of the body |
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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.
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