Vitiligo

Question 1

What is vitiligo?

Answer 1

Vitiligo = an acquired depigmenting disorder of the skin, in which melanocytes (pigment cells) are lost.

=> presents with well-defined milky-white patches of skin (leukoderma).

=> cosmetically very disabling, esp. in people with dark skin

Question 2

Who gets vitiligo?

Answer 2

Vitiligo affects all races
=> more common in India

In 50% pigment loss begins before 20 years ; In ~80% before 30 years

In 20%, other family members also have vitiligo

Males = Females

Vitiligo = higher risk of other auto-immune diseases i.e. type 1 diabetes, thyroid disease, pernicious anaemia, Addison’s disease, SLE, rheumatoid arthritis, psoriasis and alopecia areata.

=> vitiligo-like leukoderma may occur in metastatic melanoma

Question 3

What causes vitiligo?

Answer 3

Vitiligo = loss or destruction of melanocytes (cells producing melanin)
=> Melanin determines the colour of skin, hair, and eyes
=> If melanocytes can’t form melanin or decrease in number, skin colour becomes progressively lighter.

Vitiligo = systemic autoimmune disorder, associated with deregulated innate immune response
=> genetic susceptibility

New-onset vitiligo sometimes follows emotional stress

Question 4

What are the clinical features of vitiligo?

Answer 4

Vitiligo can affect any part of the body
=> single or multiple patches of skin

Common sites are exposed areas i.e. face, neck, eyelids, fingertips, toes, body folds i.e. armpits, groin, nipples, navel, lips and genitalia.

Vitiligo also favours sites of injury (cuts, scrapes, acne, thermal burns and sunburn) => Koebner phenomenon

Loss of colour also affects the hair, eyebrows, eyelashes and body.
=> white hair = ‘leukotrichia’ or ‘poliosis’.

Colour of the edge of the white patch varies:
=> usually the colour of unaffected skin, but sometimes hyperpigmented or hypopigmented

=> trichrome vitiligo = three shades of skin colour (white, pale/dark brown and normal skin)

Occasionally, each patch of vitiligo has an inflamed, red border.

Cycles of pigment loss followed by periods of stability may continue indefinitely

=> Vitiligo more evident in naturally dark skin

=> Light skinned people usually notice the pigment loss during the summer as the contrast between the affected skin and suntanned skin becomes more distinct

Question 5

How is vitiligo classified?

Answer 5

1. Non-segmental vitiligo:

Subtype : Focal, Mucosal, Acrofacial, Generalised, Universal

=> Bilateral & symmetrical distribution
=> Stable or unstable

2. Segmental vitiligo:

Subtype : Focal, Mucosal, Unisegmental, bi-or multisegmental

=> Single white patch in 90%
=> Irregular border
=> Affects young people
=> Stable after 6mths - 1yr

3. Mixed vitiligo:

Subtype : Non-segmental combined with segmental vitiligo = rare

4. Unclassified vitiligo:

Subtype : Focal at onset, Mutlifocal asymmetrical non-segmental, Unifocal mucosal

=> early disease

Question 6

How is vitiligo diagnosed?

Answer 6

Vitiligo = clinical diagnosis + no tests necessary

=> White patches seen more easily under Wood lamp examination (blacklight)

=> Dermoscopy shows a white glow

=> Skin biopsy may be recommended, esp in early or inflammatory vitiligo showing lymphocytic infiltration. Melanocytes and epidermal pigment absent in established vitiligo patches.

=> Blood tests to assess other autoimmune diseases i.e. thyroid function, B12 levels and autoantibody screen

=> Clinical photographs useful to document the extent of vitiligo for monitoring

Question 7

Vitiligo treatment:

What are the general measures?

Answer 7

Treatment of vitiligo = unsatisfactory

Repigmentation treatment most successful on face and trunk
=> hands, feet and white hair respond poorly

1. General measures

=> Minimise skin injury ; wear protective clothing.

=> Cosmetic camouflage can disguise vitiligo i.e. make-up, dyes and stains, micropigmentation or tattooing for stable vitiligo

=> Sun protection: stay indoors when sunlight is at peak, sun protective clothing + SPF 50+ sunscreen to exposed skin

• Sunburn may cause vitiligo to spread.
• Tanning of normal skin makes vitiligo patches appear more visible.

Question 8

What are the topical treatments available for vitiligo?

Answer 8

1. Corticosteroid creams
   => used for trunk/limb vitiligo for up to 3 months
   *Potent steroids avoided on thin-skinned areas i.e. eyelids, neck, armpits and groin.
2. Calcineurin inhibitors i.e. pimecrolimus cream and tacrolimus ointment
   => for vitiligo affecting eyelids, face, neck, armpits and groin.

Question 9

What is the surgical treatment for vitiligo?

Answer 9

Surgical treatment of stable vitiligo & segmental vitiligo:
=> removal of the top layer of vitiligo skin (by shaving, dermabrasion, sandpapering or laser)
=> replacement with pigmented skin removed from another site

Techniques include:

=> Non-cultured melanocyte-keratinocyte cell suspension transplantation
=> Punch grafting
=> Blister grafts formed by suction or cryotherapy
=> Split skin grafting
=> Cultured autografts of melanocytes grown in tissue culture

Question 10

Phototherapy for vitiligo:

Phototherapy = ultraviolet (UV) radiation treatment. Options include:

*unsuitable for very fair-skinned people

Answer 10

Depigmentation therapy:

=> using monobenzyl ether of hydroquinone in severely affected, dark-skinned individuals

Cryotherapy for vitiligo:

=> Cryotherapy and laser treatment used to depigment small areas of vitiligo

Question 11

What is the systemic treatment for vitiligo?

Answer 11

Systemic treatments for vitiligo may include:

Mini-pulses of oral steroids for 3 to 6 months i.e. dexamethasone, methotrexate, ciclosporin, mycophenolate mofetil

=> aims to stop progression of the disease (stabilisation)
=> so immune-modulating treatments should be considered at an early stage, particularly for vitiligo affecting the face.