Epidemiology

It occurs in about 1-2% of the population. Around 30% have clustering in families. It is more obvious but no more frequent in dark-skinned races. Sex distribution is equal.^[3][4]

Risk factors

As well as familial clustering there is an association with autoimmune thyroid disease and other autoimmune conditions, including pernicious anaemia.^[5] The presence of thyroid antibodies may well precede or follow the onset of vitiligo, especially in children, and anyone with the disease should receive regular screening, repeated if necessary.^[6]

There is also an association with certain HLA antigens in various groups. The HLA-B13 is related to thyroid disease and vitiligo.The disease can occur after trauma or injury or in response to occupational exposure to some chemicals.^[7]

History

The condition can present at any age but most commonly is noticed around the age of 20.

In early disease the white areas are indistinct and there may be pruritus.^[4]

Fig. 1. Vitiligo - note the very extensive lesions but clear demarcation

Fig. 2. Vitiligo of the hand. Very obvious on dark skin but on white skin this lesion may need Wood's light to make it more apparent.

Examination^[3][4]

• The patches of vitiligo tend to be clearly circumscribed areas of whiteness. They are especially obvious if the surrounding skin is dark. As they will not tan in sunlight they become more apparent after exposure. Furthermore, because of the loss of melanin they are also more susceptible to sunburn.
• At first there are a few clearly defined lesions that may be slightly darker around the perimeter. They increase in size and number, becoming confluent and it may be difficult, if they are extensive, to decide if it is a dark person with pale patches or a fair person with pigmented patches.
• Vitiligo can be localised or generalised. If localised, it stays within one area that is very roughly a dermatome. If generalised, it is far more diffuse and affects both sides of the body. Generalised distribution is more common.
• The face neck and scalp are most frequently affected.
• There may be a predisposition to occur in sites of repeated trauma such as bony prominences, extensor surface of the forearm, the ventral side of wrists and the dorsal side of hands and fingers. Mucous membranes may be involved as may lips, genitals, areola and nipples.
• Hair may be white or grey. It is usually in patches on the scalp but can be generalised. Other body hair, including eyebrows, pubic and axillary hair, is less commonly affected.
• Variants include trichrome vitiligo in which there is an area of partial depigmentation as well as the depigmented and normal, so that there are 3 colours. There may be marginal inflammatory vitiligo in which a raised red periphery occurs either at onset or up to a year later. Blue vitiligo may occur with postinflammatory hyperpigmentation that proceeds to vitiligo.

Investigations^[3]

• The diagnosis is generally made clinically.
• Check for evidence of associated disease like diabetes, pernicious anaemia, thyroid disease and Addison's disease.
• A Wood's light can be helpful to exclude superficial fungal infections that fluoresce in the ultraviolet light. Not all fungal infections fluoresce and the colour with which they fluoresce also varies. If a Wood's light is shone on areas of depigmentation, the exact margin is more readily seen on fair skin and the lesions appear a bright blue-white. This can be used in occupational screening for vitiligo.^[8]

Differential diagnosis^[3]

Typical vitiligo may be easy to diagnose in primary care. Atypical variations may require referral to a specialist for confirmation.^[9] Other conditions to consider include:

• Use of potent topical steroids
• Leprosy, especially the tuberculous variety
• Piebaldism
• Tinea versicolor
• Tuberous sclerosis

Management

The variety of treatments available suggests that none is totally satisfactory. The response is highly variable between patients. Guidelines were issued by the British Association of Dermatologists in 2008.^[9]

Children and adults

• Make-up and cosmetic camouflage can be very effective but should be used along with high-factor sun protection.^[4] This approach may be acceptable for adults with skin types I or II (I = highly sun-sensitive, always burns, never tans; II = very sun-sensitive, burns easily, tans minimally).
• Despite the fact that topical steroids can cause depigmentation they may be useful in vitiligo. Potent or very potent topical steroids may be used on the pigmented areas for a trial period of no more than 2 months. The patient should be warned about overuse and the possibility of skin atrophy.
• Topical pimecrolimus can be considered as an alternative to steroids and has a better side-effect profile.
• Despite the caveats about burning affected skin and darkening unaffected skin to make lesions more apparent, phototherapy can be useful for patients who do not respond to more conservative treatment, have widespread vitiligo or localised disease that significantly affects quality of life. Narrow-band ultraviolet B (UVB) is more effective than oral psoralen with ultraviolet A (PUVA). Patients with dark skin seem to fare best. Progress should be monitored with photographs every 2-3 months.
• Psychological treatments should be considered, especially in helping children to cope.
• Systemic steroids may produce benefit but this has to be weighed carefully against risks.^[1]

Adults only

• Depigmentation with p-(benzyloxy)phenol (monobenzyl ether of hydroquinone) should only be considered for adults with more than 50% depigmentation of the body or extensive pigmentation of the face or hands. Such patients should be aware that they will never be able to tan in the future.
• Surgery can be considered in adults who have cosmetically-sensitive sites where there have been no new lesions, no Köbner's phenomenon and no extension of the lesion in the previous 12 months. Split-skin grafting gives better results than micrografting.