Vitiligo is a chronic relatively common dermatologic disorder that causes depigmentation in patches of skin. It occurs when the melanocytes, the cells responsible for skin pigmentation, die or become unable to function. The precise pathogenesis, or cause, of vitiligo is complex and not fully understood. There is some evidence suggesting it is caused by a combination of autoimmune, genetic, and environmental factors. The population incidence worldwide is considered to be between 1% and 2%. There are two forms of vitilgo, non-segmental and segmental, with non-segmental vitiligo being far more prevalent than its segmental counterpart.
The most notable symptom of vitiligo is the depigmentation of patches of skin that occurs on the extremities. Although patches are initially small in size, they can often start to 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 a tendency to hyperpigment around the edges. In a more general sense, vitiligo is similar in appearance to leprosy, and as such (in countries where leprosy is prevalent), individuals with vitiligo can be stigmatized for the similarities in appearance. In regards to psychological damage, vitiligo can have a significant effect on the mental health of a patient. Psychological stress may even result in an individual becoming more susceptible to vitiligo. Patients who are stigmatised for their condition may result in depression and similar mood disorders.
In non-segmental vitiligo (NSV), there is usually some form of symmetry in regards to the location of the patches of depigmentation. New patches also appear over time, and can be generalised over the a large portions of the body, or localised 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.
Segmental vitiligo (SV) differs in appearance, aetiology and prevalence of associated illnesses. Its treatment is also different to 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, patches of depigmented skin remain throughout life.Top ^
Vitiligo is associated with autoimmune and inflammatory diseases, commonly thyroid overexpression and underexpression. JA 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.
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's 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.
There are a number of ways to alter the appearance of vitiligo without addressing its underlying cause. 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 the sun tanning of unaffected skin. However, exposure to sunlight may also cause the melanocytes to regenerate to allow the pigmentation to come back to its original color.
The traditional treatment given by most dermatologists is corticosteroid cream.
Phototherapy may also be beneficial. Using exposure to long-wave ultraviolet (UVA) light from the sun or from UVA, together with Psoralen, called "PUVA", Or with UVB Narrowband lamps (without Psoralen), can help in many cases. Psoralen can be taken in a pill 1–2 hours before the exposure or as a Psoralen soaking of the area 1/2 hour before the exposure. Lately, PUVA is being more and more replaced with exposure UVB Narrowband light at a wavelength of 311-313 nanometers. This treatment does not involve Psoralen since the effect of the lamp is strong enough. The source for the UVB Narrowband UVB light can be special fluorescent lamps that treat large areas in a few minutes, or high power fiber-optic devices in a fraction of a second.
Studies have also shown that immunomodulator creams such as Protopic and Elidel also cause repigmentation in some cases, when used with UVB Narrowband treatments.
Alternatively, some people with vitiligo opt for chemical depigmentation, which uses 20% monobenzone (monobenzylether of hydroquinone). This process is irreversible and generally ends up with complete or mostly complete depigmentation.
In late October 2004, doctors successfully transplanted 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 and used to make a cellular suspension. The area to be treated was then ablated with a medical laser, and the melanocyte graft applied. Three weeks later, the area was exposed to UV light repeatedly for two months. Between 73 and 84 percent of patients experienced nearly complete repigmentation of their skin. The longevity of the repigmentation differed from person to person. In the 1980s, dermatology professor Aaron B. Lerner had pioneered a skin transplantation therapy for vitiligo.
In early 2008 scientists at King's College London discovered that piperine, a chemical derived from black pepper can aid repigmentation in skin, especially when combined with UV therapy produces a longer lasting and more even pigmentation than previous treatments.
Support groups and organizations are available to help people learn more about vitiligo, understand treatment options, and find support from other people with vitiligo.
Vitiligo Support International is the largest vitiligo organization in the world. The nonprofit organization provides free access to online message boards, chat rooms, frequently asked questions, information and articles, as well as a patient-referred doctor search. The group advocates on behalf of patients, conducts patient conferences and has local support groups.
The National Vitiligo Foundation (NVF) is a 501©(3) nonprofit organization that provides access to online resources, physician listings, frequently asked questions (etc); funds research through grants and sponsors local support groups and workshop style conferences.