skin changes >vitiligo
Vitiligo (vit-ill-EYE-go) is a pigmentation disorder in which melanocytes (the cells that make pigment) in the skin, the mucous membranes (tissues that line the inside of the mouth and nose and genital and rectal areas), and the retina (inner layer of the eyeball) are destroyed. As a result, white patches of skin appear on different parts of the body. The hair that grows in areas affected by vitiligo usually turns white.
The cause of vitiligo is not known, but doctors and researchers have several different theories. One theory is that people develop antibodies that destroy the melanocytes in their own bodies. 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 to cause vitiligo.
How Is Vitiligo Diagnosed?
If a doctor suspects that a person has vitiligo, he or she usually begins by asking the person about his or her medical history. Important factors in a person's medical history are 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 need to know whether the patient or anyone in the patient's family has had any autoimmune diseases and whether the patient is very sensitive to the sun. The doctor will then examine the patient to rule out other medical problems. The doctor may take a small sample (biopsy) of the affected skin. He or she 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). 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.
What are the symptoms of vitiligo?
In childhood, vitiligo frequently appears as 'halo naevi', in which areas of depigmentation surround small, pigmented naevi. (A naevus is any clearly defined skin abnormality present at birth.) The areas of depigmentation are usually seen first on skin that is exposed to light, particularly the face or back of the hands. Initially the pigment loss is often patchy, with areas of partial loss close to areas with complete absence of melanin. Often it is symmetrical with both halves of the body equally
Affected, but occasionally only one segment of skin will be involved (so-called segmental vitiligo). Some sufferers will have the Koebner phenomenon, in which skin changes occur at the site of skin trauma. In this situation, vitiligo can develop at the site of abrasions, surgical scars and even eczema or psoriasis. The hairs in areas of vitiligo either remain pigmented or can go white (leukotrichia). Occasionally premature greying of hair can occur not only in vitiligo patients but also in their relatives.
People who develop vitiligo usually first notice white patches (depigmentation) on their skin. These patches are more common in sun-exposed areas, 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, and genitals.
Vitiligo generally appears in one of three patterns. In one pattern (focal pattern), the depigmentation is limited to one or only a few areas. Some people develop depigmented patches on only one side of their bodies (segmental pattern). But for most people who have vitiligo, depigmentation occurs on different parts of the body (generalized pattern). 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.
Vitiligo causes light or white patches on your skin that are symmetrical (even), with well-defined dark or red borders. The patches can occur anywhere, but the areas most commonly affected are the backs of the hands, the face, and areas that have skin folds, such as the armpits and genitals. Body openings, such as the lips, eyes and nipples, and areas that have been sunburned are also common areas for vitiligo.
The loss of pigment may be rapid during the beginning stages of the condition, but later, the condition may not progress for long periods.
There are a number of ways to alter the appearance of vitiligo without addressing its underlying cause. In mild cases, vitiligo patches can be hidden with makeup or other cosmetic solutions. If the affected person is pale-skinned, the patches can be made less visible by avoiding sunlight and the sun tanning of unaffected skin. However, exposure to sunlight may also cause the melanocytes to regenerate to allow the pigmentation to come back to its original color.
Methods for removing the white patches include corticosteroids, calcineurin inhibitors, ultraviolet light and surgery, but they are not very effective. Current treatments include exposure to Narrow Band UV-B light, which seems to blur the edges of patches, and lightly freckling the affected areas. Scientific studies have also shown that immunomodulator creams such as Protopic and Elidel also cause repigmentation in some cases.
Alternatively, some people with vitiligo opt for chemical depigmentation, which uses 20% monobenzylether of hydroquinone. This process is irreversible and generally ends up with complete or mostly complete depigmentation.
In late October of 2004, doctors successfully transplanted melanocytes to vitiligo affected areas, effectively repigmenting the region. The procedure involved taking a thin layer of pigmented skin from the patient's gluteal region. Melanocytes were then separated out and used to make a cellular suspension. The area to be treated was then ablated with a medical laser, and the melanocyte graft applied. Three weeks later, the area was exposed to UV light repeatedly for two months. Between 73 and 84 percent of patients experienced nearly complete repigmentation of their skin. The longevity of the repigmentation differed from person to person.
Who is affected by vitiligo?
About 1 to 2% of people in the world, or 40 to 50 million people, have vitiligo. In the United States alone, 2 to 5 million people have the disorder.
Ninety-five percent of people who have vitiligo develop it before their 40th birthday. The disorder affects all races and both sexes equally.