The colour of your skin
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- Published 17.05.10
Indians are very conscious of their skin colour. There is great alarm and anxiety if the skin suddenly develops white patches. About 1 per cent of the population is affected by this condition — called leukoderma (white skin) or vitiligo (“streaked calf” in Greek). The patches usually appear between the ages of 12 and 40. The disease affects people in all socio-economic strata. Michael Jackson was affected by it. Other rich and famous sufferers are Amitabh Bachchan and Gautam Singhania, the chairman and managing director of Raymonds.
The sudden loss of pigmentation causes 25 per cent of these people to become obsessed with their skin colour, depressed or even suicidal. Money does not make the disease disappear; it only makes it possible to consult the world’s best dermatologists.
The de-pigmentation often starts on the hands and feet. In the case of Jackson, it first appeared on his hands. This was the reason behind his signature white glove. In others it may start around orifices like the nose, mouth, eyes, umbilicus, genital areas and rectum. The patches may remain stationary, increase in size or spread over the whole body. They are symmetrical on both sides of the body. Some areas may suddenly re-pigment while the white patches continue to spread.
The loss of colour is due to the mutation of one of the genes on chromosome 17. This is usually inherited. The mutations may remain unexpressed and the person may be normal all through life. However, if a family member is affected, the risk of vitiligo developing eventually in another member is increased five-fold. The same gene is responsible for premature greying. Some members may have patches, others may develop grey hair in their twenties while still others may appear perfectly normal. The gene may start to express itself and cause de-pigmentation as a result of a trigger like a stressful event. It may also be precipitated by an injury or constant friction in shoes or clothing.
The mutated gene triggers an autoimmune disorder and the body forms antibodies against melanocytes (pigment producing cells). The latter are thus destroyed. Vitiligo may be associated with other autoimmune disorders which affect organs such as the thyroid, stomach and adrenal glands. It may form part of the spectrum of systemic lupus (an autoimmune disease that affects all the organs in the body, and is thus difficult to diagnose).
Sometimes a white baby is born to a “normal” family. The entire skin, hair and even the eyes lack pigment. This condition is called albinism and the person is referred to as an albino. It occurs because the melanocytes are unable to produce melanin, the colouring pigment. This is also an inherited condition but since the gene is recessive it does not express itself and manifest itself as a “white baby” unless it is inherited from both parents. A person who carries the gene may look normal and not be aware of it. If he or she incidentally marries another carrier, the child can be albino.
The pigment producing melanocytes may be absent from birth in certain areas. This hereditary condition is called piebaldism. It can occur anywhere, and can result in just a white forelock — like in the case of Indira Gandhi.
Owing to the similarity in symptoms, vitiligo is sometimes confused with piebaldism, albinsim or even leprosy. White scars may give rise to a similar appearance. A diagnosis can be reached by a skin biopsy.
It is better to avoid sunlight when vitiligo first appears. As the skin tans, the areas without melanin become obvious. Use an umbrella or apply SF (sunfilter) 30 sunscreen on the exposed areas.
Small patches can be camouflaged with cosmetics. They can also be treated under supervision by applying steroid creams. Constant use of these creams, however, can damage the skin texture.
Physicians in India and Egypt documented vitiligo as early as 1,500 BC. They treated it by applying and administering extracts of the fruit, seeds and leaves of two plants — Psoralea coryifolia Linnaues and Ammi majus Linnaeus. Even today, isolates of these plants are successfully used topically and orally. Synthetic compounds are also available. They act by increasing sensitivity to light and augmenting pigmentation in the affected areas (photochemotherapy). Treatment usually involves exposure to a measured amount of natural sunlight (PUVASOL) or artificial UV radiation (PUVA) to induce re-pigmentation. Phototherapy (without light-sensitising chemicals) can also be used. Sunburn is a common complication.
Surgical treatment can be tried by using skin grafts from pigmented areas. The success rate varies between 65 and 90 per cent. If the de-pigmented areas are extensive, some patients bleach the remaining dark portions of the skin to achieve a universal white colour.
Dr Gita Mathai is a paediatrician with a family practice at Vellore. Questions on health issues may be emailed to her at firstname.lastname@example.org