Vitiligo

Vitiligo is a condition that causes depigmentation of patches of skin. It occurs when melanocytes, the cells responsible for skin pigmentation, die or are unable to function. The cause of vitiligo is unknown, but research suggests that it may arise from autoimmune, genetic, oxidative stress, neural, or viral causes. The incidence worldwide is less than 1%. The most common form is non-segmental vitiligo.

Signs and symptoms
The most notable symptom of vitiligo is depigmentation of patches of skin that occurs on the extremities. Although patches are initially small, they often enlarge and change shape. When skin lesions occur, they are most prominent on the face, hands and wrists. Depigmentation is particularly noticeable around body orifices, such as the mouth, eyes, nostrils, genitalia and umbilicus. Some lesions have hyperpigmentation around the edges. Patients who are stigmatised for their condition may experience depression and similar mood disorders.

Treatment
There are a number of treatments that cure Vitiligo. Treatment options generally fall into four groups:

UVB Phototherapy
Exposing the skin to UVB light from UVB lamps is the most common treatment for Vitiligo.

The treatments can be done at home with a domestic UVB lamp or in a clinic. Normally a small lamp is needed if the spot is small.

Treatment can take a few weeks if the spots are on the neck and face and if they existed not more than 3 years. If the spots are in the the hands and legs and more than 3 years it can take few months.

In a clinic the treatments are done 2-3 times a week, and at home every day, which makes the home treatments more effective.

If the spots are on large area of the body, full body treatment in a clinic or hospital are needed.

Both UVB Broadband and UVB Narrowband lamps can be used.

Narrow-band ultraviolet B is a useful and well-tolerated treatment for vitiligo.

Treatment of vitiligo Treatment of vitiligo with broadband ultraviolet B and vitamin

Adding a Psoralen, a material that increases the effect of the UV light, can speed the cure, especially if the spots are in the hands or legs, where the cure can take several months.

Studies have shown that immunomodulator creams such as Protopic and Elidel also cause repigmentation in some cases, when used with UVB narrowband treatments.

A 1997 report suggests that combining Vitamin B12 and folic acid supplements with sun exposure caused repigmentation in 52% of cases.

PUVA Phototherapy
Ultraviolet light (UVA) treatments are normally carried out in a hospital clinic. Psoralen and Ultraviolet A light (PUVA) treatment involves taking a drug which increases the skin sensitive to ultraviolet light. The skin is then exposed to high doze of ultraviolet A light (UVA). Treatment is required twice a week for 6–12 months or longer. Because of the high doze of UVA and the Psoralen, PUVA may cause side effects such as 'sunburn' type reactions or skin freckling.

Narrowband ultraviolet B (UVB) phototherapy is now used more commonly than PUVA as it is less damaging to the skin. As with PUVA, treatment is carried out twice weekly in a clinic or every day at home, and there is no need to use a Psoralen.

A few preliminary trials have been carried out using the herb ginkgo biloba. A small scale open label pilot clinical trial found the progression of vitiligo stopped in all participants; the total VASI (Vitiligo Area Scoring Index) indicated an average repigmentation of vitiligo lesions of 15%. The authors conclude "Larger, randomized double-blind clinical studies are warranted and appear feasible."

Transplanting Melanocytes
In October 1993, a scientific report was published of successfully transplanting melanocytes to vitiligo affected areas, effectively repigmenting the region. The procedure involved taking a thin layer of pigmented skin from the patient's gluteal region. Melanocytes were then separated out to a cellular suspension that was expanded in culture. The area to be treated was then denuded with a dermabrader and the melanocytes graft applied. Between 70 and 85 percent of patients experienced nearly complete repigmentation of their skin. The longevity of the repigmentation differed from person to person.

Skin camouflage
In mild cases, vitiligo patches can be hidden with makeup or other cosmetic camouflage solutions. If the affected person is pale-skinned, the patches can be made less visible by avoiding sunlight and sun tanning of unaffected skin.

Reversal
The traditional treatment used by dermatologists is the application of corticosteroid cream.

De-pigmenting
In cases of extensive vitiligo the option to de-pigment the unaffected skin with topical drugs like monobenzone, mequinol or hydroquinone may be considered to render the skin an even colour. The removal of all the skin pigment with monobenzone is permanent and vigorous sun-safety must be adhered to for life to avoid severe sun burn and melanomas. Depigmentation takes about a year to complete.

Non-segmental
In non-segmental vitiligo (NSV), there is usually some form of symmetry in the location of the patches of depigmentation. New patches also appear over time and can be generalized over large portions of the body or localized to a particular area. Vitiligo where little pigmented skin remains is referred to as vitiligo universalis. NSV can come about at any age, unlike segmental vitiligo, which is far more prevalent in teenage years.

Classes of non-segmental Vitiligo include:
 * Generalized Vitiligo: the most common pattern, wide and randomly distributed areas of depigmentation
 * Universal Vitiligo: depigmentation encompasses most of the body
 * Focal Vitiligo: one or a few scattered macules in one area, most common in children
 * Acrofacial Vitiligo: fingers and periorificial areas
 * Mucosal Vitiligo: depigmentation of only the mucous membranes

Segmental
Segmental vitiligo (SV) differs in appearance, etiology and prevalence from associated illnesses. Its treatment is different from that of NSV. It tends to affect areas of skin that are associated with dorsal roots from the spine. It spreads much more rapidly than NSV and, without treatment, it is much more stable/ static in course and it is associated with auto-immune diseases and a very treatable condition that responds to topical treatment.

Differential diagnosis
Conditions with similar symptoms include:
 * Pityriasis alba
 * Tuberceloid Leprosy
 * Post inflammatory hypopigmentation
 * Tinea versicolor
 * Albinism
 * piebaldism
 * idiopathic guttate hypomelanosis
 * progressive macular hypomelanosis

Pathogenesis
Vitiligo is a disorder characterized by patchy loss of skin pigmentation due to immune attacks on melanocytes. While there is no significant proof or evidence for this, many doctors believe that it can be caused by defects in many genes. Variations in genes that are part of the immune system or part of melanocytes have both been associated with vitiligo. The immune system genes are associated with other autoimmune disorders.

In one case, the gene TYR, which makes the melanocyte more susceptible to the immune system in vitiligo, also makes the melanocyte more susceptible to the immune system in the skin cancer malignant melanoma. So people with vitiligo caused by the TYR gene are less likely to have malignant melanoma.

A genomewide association study found 10 independent susceptibility loci for generalized vitiligo, responsible for 7.4% of the genetic risk. Some patients had vitiligo alone; others had generalized vitiligo with other autoimmune diseases. Most loci were associated with both forms. (The exception was PTPN22, which was only associated with generalized vitiligo.) In the MHC region, which controls the immune system, major association signals were identified in the class I gene region (between HLA-A and HLA-HGC9) and class II gene region (between HLA-DRB1 and HLA-DQA1). Outside the MHC region, association signals were identified near RERE, PTPN22, LPP, IL2RA, GZMB, UBASH3A and C1QTNF6 genes, which are associated with other autoimmune diseases. TYR encodes tyrosinase, which is not a component of the immune system, but is an enzyme of the melanocyte that catalyzes melanin biosynthesis, and a major autoantigen in generalized vitiligo. The major alleles of TYR are associated with vitiligo, and the minor alleles are associated with malignant melanoma. Vitiligo-associated 402R tyrosinase may be more efficiently presented to the immune system. Melanoma-associated 402Q may fail to be identified by the immune system.

The transcriptional profile of melanocytes from vitiligo patients have been studied. Oligonucleotide microarrays containing approximately 16,000 unique genes were used to analyse mRNA expression in melanocytes from vitiligo patients and age-matched healthy controls. In total, 859 genes were identified as differentially expressed.

Vitiligo is sometimes associated with autoimmune and inflammatory diseases, commonly thyroid overexpression and underexpression. A study comparing 656 people with and without vitiligo in 114 families found several mutations (single-nucleotide polymorphisms) in the NALP1 gene.The NALP1 gene, which is on chromosome 17 located at 17p13, is on a cascade that regulates inflammation and cell death, including myeloid and lymphoid cells, which are white cells that are part of the immune response. NALP1 is expressed at high levels in T cells and Langerhan cells, white blood cells that are involved in skin autoimmunity. Polymorphisms of CD4 were shown to be associated with the vitiligo and other autoimmune diseases like type I Diabetes Mellitus.

Among the inflammatory products of NALP1 are caspase 1 and caspase 5, which activate the inflammatory cytokine interleukin-1β. Interleukin-1β is expressed at high levels in patients with vitiligo. There are compounds which inhibit caspase and interleukin-1β, and so might be useful drugs for vitiligo and associated autoimmune diseases. In one of the mutations, the amino acid leucine in the NALP1 protein was replaced by histidine (Leu155->His). The original protein and sequence is highly conserved in evolution, and found in humans, chimpanzee, rhesus monkey, and bush baby, which means that it is an important protein and an alteration is likely to be harmful. Addison's disease (typically an autoimmune destruction of the adrenal glands) may cause vitiligo.

Notable cases

 * Michael Jackson was diagnosed with vitiligo in 1986. In a 90-minute interview with Oprah Winfrey in February 1993, Jackson claimed that he didn't bleach his skin, stating for the first time that he had vitiligo. A friend claimed he started wearing his signature sequin glove to cover the vitiligo that had begun to appear in the early 80s.  It was also claimed by Jackson during a leaked deposition tape in 1996, that he did not "bleach" his skin. The tape was leaked months after his death in June 2009. This is further reinforced in the official autopsy report which confirms Jackson's diagnosis with the skin condition.
 * Graham Norton, Irish television personality.
 * Lee Thomas, a news anchor and entertainment reporter for WJBK (Fox) Detroit.
 * Yvette Fielding, British TV presenter, has had vitiligo from age 11; her mother developed it at age 24.
 * John Wiley Price, Dallas County Commissioner.
 * Amitabh Bachchan, Bollywood actor.
 * Scott Jorgensen, UFC fighter.
 * Daniel Bryan, professional wrestler, WWE superstar.
 * Jon Hamm, actor best known for his role in Mad Men.
 * John Henson, one of the hosts of ABC's Wipeout has vitiligo and has a white patch of hair on the right side of his head from it.
 * Krizz Kaliko, rapper from Kansas City, Missouri, is affected by vitiligo mostly around the eyes. He also named his debut album after the condition.
 * J. D. Runnels, an American football fullback, who is affected by vitiligo around his eyes and mouth.
 * Francesco Cossiga, former President of Italy. Vitiligo became evident after the stress he underwent, being both a minister of Interior in charge then and friend and fellow party member of the victim, during kidnapping and murder of Aldo Moro by the Red Brigades.
 * Holly Marie Combs suffers from it on her hands.