Vitiligo

It affects approximately 1 person in every 200 of the population. Around 40 per cent of patients have an affected family member.

What causes vitiligo?

Healthy skin contains melanin, a brown pigment produced from the amino acid tyrosine by pigment cells (melanocytes) in the skin.

If skin affected by vitiligo is examined under a 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.

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. Symptoms involve the physical appearance as well as its psychological impact.

Physical appearance

- 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.

Psychological impact

This varies greatly from person to person, depending on their condition, their social and occupational situation and their psychological wellbeing.

Vitiligo is often most obvious in darkly pigmented individuals, in whom the disease can have profound psychological consequences. These effects ranges from mild embarrassment to a severe loss of self-confidence and social anxiety, especially for those who have lesions on exposed skin.

Can vitiligo be a sign of serious disease?

Malignant melanoma (cancer of the melanocyte) can develop simultaneously with vitiligo. However, the vast majority of patients with vitiligo do not have this cancer, which tends to occur at a later age.

Patients have an increased chance of developing any of the autoimmune diseases, which include Addison's disease, thyroid problems (hyperthyroidism and hypothyroidism), diabetes and alopecia areata (patchy hair loss).

What is the treatment?

Patients need to use strong sunscreens to prevent sunburn of severely affected skin. Several treatments exist that aim to hide or reverse depigmentation, or prevent further pigment loss from occurring. None are universally successful and all have limitations.

- Camouflage: the depigmented areas can be covered with makeup or topical dyes that are applied to the skin. Specific advice can be obtained from a camouflage clinic (see 'Support groups and relevant organisations below).
- Photochemotherapy has been used extensively for vitiligo. This treatment combines a light-activated drug (psoralen) with ultraviolet A (UVA) irradiation (hence it is called PUVA). PUVA is rarely completely successful and often requires many treatments over months, which is a considerable commitment for the patient. Studies show PUVA offers only a slight advantage over placebo (dummy treatment).
- Corticosteroids, both topical (applied to the skin) and systemic (as tablets or by injection) are used for vitiligo. While there is no doubt that the degree of improvement is greater than one would expect with placebo therapy, less than 50 per cent of patients respond to this treatment.
- Skin grafting: in dark-skinned patients, skin grafting of pigmented skin samples from another body site can stimulate repigmentation.
- Depigmentation: where depigmentation has been extensive, a monobenzyl ether of hydroquinone can be used as a cream to remove remaining areas of pigment. This treatment is usually a last resort, but occasionally it is the best approach for a patient.

What is the outlook?

Vitiligo usually slowly progresses, often in fits and starts - ie it will extend rapidly over a short period of months and then show little change over subsequent years.

Treatment is generally unsatisfactory - long-term PUVA will help a proportion of patients. Small skin grafts or potent topical steroid preparations occasionally help cosmetically disabled patients.

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