Vitiligo

 

Mbah Dukun listen the music, oldies song, do you know Michael Jackson? King of Pop? Yeah he was famous singer, everybody know who he is. He was a Afro American, however his skin changes to be white? How could it be happened? The anwer is…..

Vitiligo is a non contagious acquired pigmentation disorder characterized by sharply-defined white or loss the pigment of patches  variable shape and dimensions, increasing in size and number with time.

Etiology

The exact cause of vitiligo is not known. It is an autoimmune disease that is believed to be hereditary. The proposed theories are that stress, thyroid dysfunction, skin injury, severe sunburns, chemicals, and medicines combined with the genetic tendency towards vitiligo can all contribute to the condition. However, these are theories that have not yet been substantiated.

Differential diagnosis

Differential diagnosis is made versus:
1) piebaldism, which is a rare depigmentation disorder due to a mutation of c-kit protooncogene affecting the differentiation and migration of melanocytes. It is characterized by stable and circumscribed white patches (with absence of melanocytes) present at birth, affecting the face (especially the central area with localized poliosis), sternal and abdominal zones, knees and elbows;
2) achromic nevus, which is a well-limited depigmented area, stable and evident at birth, in which melanocytes are either normal or reduced;
3) post-inflammatory leukoderma (e.g., after psoriasis or syphilis) in which patients have a history of pre-existing dermatosis;
4) pytiriasis versicolor, where mycologic examination reveals hyphae and spores;
5) depigmented lesions in leprosy, which shows anesthetic disturbance of sensibility.

Clinical description

The clinical picture consists of one or more well-demarcated and white maculae, progressing in size and number. They are asymptomatic generally. The lesions usually appear on sun-exposed or constitutionally hyperpigmented areas or on sites of stretch and pressure (face, dorsum of hands and fingers, external genitalia, knees and elbows). The margins of the patches are often hyperpigmented; hypopigmented areas sometimes occur together with the depigmented lesions and the normally pigmented skin (trichrome vitiligo). Rarely an inflammatory border may be found around the vitiligo patch resulting in a raised and erythematous edge (inflammatory vitiligo). Poliosis circumscripta, as well as canities and premature graying, can be observed; mucosae are rarely involved.
A. Vitiligo classification by Nordlund
Nordlund established a clinical classification based on distribution and extension of lesions (3). Three types have been delineated: localized, generalized and universal vitiligo.
1. Localized vitiligo
Localized vitiligo is classified into focalis (one or more patches in one area but not in a segmental pattern) and segmental (one or more maculae in dermatomal distribution) forms.
2. Generalized vitiligo
Generalized vitiligo can be subdivided into acrofacial (affecting face and distal extremities), vulgaris (the most common variety, with a symmetrical distribution of lesions in typical zones) and mixed (segmental plus vulgaris or acrofacial) types.
3. Universal vitiligo
Universal vitiligo involves more than 80% of the body.
B.Vitiligo classification by Koga
This is a more recent classification subdividing vitiligo into two clinical types: vitiligo non segmentalis (type A) and vitiligo segmentalis (type B) and (4).
1.Type A
Type A is more common, has a potential lifelong evolution and is associated with Koebner phenomenon and frequently with autoimmune diseases, such as Sutton nevus, thyroid disorders, juvenile diabetes mellitus, pernicious anemia and Addison’s disease.
2. Type B
Type B is rarer and has a dermatomal distribution; after rapid onset and evolution it usually exhibits a stable course.
The natural course of the disease is generally unpredictable, but it is often progressive; some degree of spontaneous repigmentation occurs in 10-20% of patients, but it is rarely cosmetically acceptable (5), often occurring in a perifollicular pattern.

Treatment

Vitiligo is a challenging disease to treat. Most of the available treatments are not 100% successful. General aspects of treatments that need to be addressed include psychological support, use of sunscreens and camouflage cosmetics. There are a range of treatment modalities for re-pigmentation, which is discussed below.
a. General aspects
Psychosocial support-vitiligo can have a devastating effect on sufferers, affecting self-esteem and consequently, the ability of individuals to form and maintain relationships. Thus, it is important that psychological help is sought and given to sufferers. There are various support groups worldwide and joining this may be of help. Please click on our educational link for details of vitiligo support groups. Camouflage cosmetics can help to disguise the pigmentary abnormalities, especially for localized patches on the face. It is important that the right shade is used and proper application techniques are taught. The use of high factor broad-spectrum sunscreens is advisable in vitiligo sufferers. Other camouflage techniques, which can be used for this disorder, include self-tanning preparations, topical dyes and tattooing. These techniques generally do not result in an ideal colour match.
b. Re-pigmentation Techniques
The choice of re-pigmentation techniques depends on the location and size of the white patches. Treatment options that are of use in current clinical practice are discussed below.
1. Corticosteroids
Corticosteroids can be applied to lesional skin as a cream. It is efficacious in the treatment of localized patches of vitiligo and works by modifying the immune cells in lesional skin. The correct strength must be used on the appropriate sites of the body for the right time. Hence, steroid creams must be used under medical supervision.
2. Topical Calcipotriene
These agents when used as monotherapy have minimal effect in inducing re-pigmentation of vitiliginous lesions. When combined with phototherapy (such as PUVA) or with topical steroids (compound creams are available), they can be useful in selected patients.
3. Ultraviolet radiation
Ultraviolet radiation can induce re-pigmentation of the skin in patients with vitiligo. The mode of action is via modulation of the immune system. Natural sunlight can be used, as well as UVA with a psoralen (PUVA) and UVB. PUVA and UVB are types of ultraviolet radiation, distinguished by their wavelength. With PUVA, a psoralen, which absorbs the UVA, is given as a tablet (oral PUVA) or applied topically to the skin. UVB, especially narrow-band UVB (NBUVB)
is more efficacious for treating widespread vitiligo. Furthermore, evidence to date, indicates that it is associated with fewer side effects compared to PUVA. For an in-depth discussion on the uses of PUVA and UVB, please read our upcoming article on ‘the uses of phototherapy in blacks’.
4. Excimer laser
This is a targeted laser, with a wavelength of 305nm, similar to the spectrum of UVB. Studies have shown that this laser promotes re-pigmentation in vitiligo when used as monotherapy or in combination with topical tacrolimus. It is an alternative therapy for treating localized patches of vitiligo in units where it is available. For an in-depth review of the excimer laser, please read the article ‘lasers and light therapy in blacks’.
5. Surgical techniques
There are various surgical techniques, which can be used for grafting normal skin onto affected sites of vitiligo. This allows melanocytes (pigment producing cells of the skin) to be transplanted onto lesional sites, thereby inducing re-pigmentation of the affected sites.
Practitioners performing these techniques must be well trained, as complications may arise. To have success with this technique, appropriate selection of patients is mandatory. In fact, a number of studies have shown that surgical treatments are satisfactory when they are implemented to patients with stable type vitiligo, which is unresponsive to conventional therapies. The surgical techniques available include suction blister grafting, split-thickness skin grafting, punch grafting, follicular grafting, injection of cultured melanocytes and non-cultured melanocytes transplantation. This will be discussed in-depth in an upcoming article on surgical procedures in dermatology.
c. De-pigmentation Therapy
Where a large proportion of the skin is affected by vitiligo, another mode of treatment is to de-pigment unaffected skin using potent agents (monobenzones). Once this is done, the skin will be more sensitive to light and for this reason, general sun protection advice should be given. This will include the use of a high factor broad-spectrum sunscreen.
d. Special Issue-Topical Calcineurin Inhibitors
The calcineurin inhibitors, Tacrolimus and Elidel (pimecrolimus), are approved for the treatment of atopic dermatitis. Their mechanism of action is via modulation of the immune system. Recently both have had a black box warning of cancer risk applied to them by the US Food and Drug Administration (FDA). Although there has been published data indicating both medications are successful in treating localized patches of vitiligo, the FDA has not approved the use of either medication for treating vitiligo. Accordingly, treating vitiligo with them is an off label use. We advice our readers to discuss with their skin care physicians about the risks and benefits of their use for vitiligo prior to use.


refferences
1. http://blackhealthmatters.org/Vitiligo.pdf
2. http://www.hcvadvocate.org/hepatitis/factsheets_pdf/Vitiligo_09.pdf
3. http://www.orpha.net/data/patho/GB/uk-vitiligo.pdf