Last updated: 9 July 2009
Introduction
Vitiligo is a common pigmentary disorder in which the pigment producing cells of the skin (melanocytes) are absent or not functioning properly. As a result, lighter patches of skin appear in different parts of the body due the lack of melanin (pigment). Mucous membranes, such as the tissue inside the mouth, nose and the retina can also be affected. The hair growing on areas affected by Vitiligo can also turn white.
Incidence
The incidence of Vitiligo is thought to range from 0.5% - 2% in the population, affecting as many as 65 million people. It has been found affect both genders and all races equally; however it might appear to affect a higher percentage of darker individuals because the contrast in skin colour is greater, making it seem more obvious. The onset of this disease can be at any age but incidence usually peaks between the ages of 20 and 30. Vitiligo is known to progress and there is no cure available.
Causes
The cause of Vitiligo is unknown but is currently accepted that it is an autoimmune disease, where the individual’s immune system mistakes the body’s own tissue to be foreign and attacks it. Other theories include environmental/toxic contributors and melanocytes destroying themselves. Some people have reported that sunburn or stress has triggered Vitiligo but it has yet to be scientifically proven. 30% of people with Vitiligo have a family member that also has the disease, indicating that it might be hereditary.
Symptoms
Vitiligo commonly affects sun-exposed areas or areas of injury on the body, including the face, lips, hands, arms and feet. People who develop it usually first notice white patches on their skin. It often starts as a small area of pigment loss which can spread and become larger over time. Other common areas for patches to appear are the groin, armpits, torso, wrists, elbows, knees, nostrils and genitals. The severity of Vitiligo varies with different people and there is no way to predict how much pigment a person will lose or if it will spread.
Vitiligo generally appears as one of three patterns:
- Focal – depigmentation is limited to one particular area
- Generalized – the most common pattern, depigmentation is widespread and affects both sides of the body in a symmetrical manner
- Universal – a rare form of Vitiligo, this involves complete or near complete depigmentation
Other less common signs include:
- Premature graying of the scalp hair, eyelashes, eyebrows or beard
- Loss of colour in the retina (inner layer of the eye)
- Loss of colour in mucous membranes such as the skin that lines the inside of your mouth
Treatments
The main goal of treating Vitiligo is to improve the appearance of patients, however many are unsuccessful. Vitiligo doesn’t cause physical impairments but many patients choose to treat it in order to cope with the emotional distress it causes them. Many treatment options exist but challenges persist, as not all patients respond to available therapies and relapse is common. Factors such as the extent, distribution, and progression rate of the depigmentation dictate the choice of treatment.
Treatment includes self care, topical treatments, surgical intervention, and phototherapy.
Self care
There are effective ways for patients to protect their skin and improve the appearance of Vitiligo without medical intervention.
- Minimize sun exposure and ensure that protective clothing and sunscreen are worn whilst in the sun to protect against UV rays
- The use of cosmetics such as make up and tanning lotions to cover up the patches of skin.
Topical treatments
Many of the medical therapies available are applied topically and can reduce the appearance of Vitiligo.
- Topical steroid therapy – steroid creams such as Mometasone furoate may aid in the repigmentation of Vitiligo patches
- Depigmentation therapy – if a dark skinned individual has Vitiligo that affects large areas of exposed skin, they may choose to undergo depigmentation with bleaching creams containing hydroquinone.
- Immunomodulators – creams with agents such as Tacrolimus can be used to adjust the way the immune system functions.
Surgical intervention
Surgical therapies are only recommended for patients with stable Vitiligo, that is, patients whose patches have not grown or spread for at least 6 months. They are usually very costly and can leave scarring. They are only considered after other therapies have proven to be ineffective.
- Skin grafts – surgeons can remove skin from the patients own body or from a donor and attach it to an affected area.
- Tattooing – manual tattooing of depigmented areas
- Melanocyte transplantation – still an experimental procedure, doctors transplant normal melanocytes into the depigmented patches.
Phototherapy
Ultraviolet light can be used as a therapy to restore pigment in the skin. Up to 50 sessions of treatment may be needed before the patient sees results. It is also common for the response to be incomplete and relapse to occur. Even is the treatment is successful there is no way of knowing or preventing the patches from extending. The variations in light therapy for Vitiligo include the uses of:
- PUVA – Psolaren plus UV-A radiation.
- Narrowband UV-B radiation
- Targeted phototherapy using an excimer laser
Introduction
Vitiligo is a common pigmentary disorder in which the melanocytes in the skin are absent or not functioning correctly. As a result, lighter patches of various shapes and sizes; appear in different parts of the body due a lack of melanin. Lesions on the face and the back of the hands are very prominent. Mucous membranes, such as the tissue inside the mouth, nose and the retina can also be affected. The hair growing on areas affected by Vitiligo can also turn white, often being referred to as Poliosis.
Epidemiology and prevalence
Vitiligo occurs worldwide, with a prevalence of 0.5-2%. It affects all races and both sexes equally, but is more noticeable in races where the contrast in skin color is more obvious. A female predominance of Vitiligo has been reported but remains statistically irrelevant. These discrepancies could be attributed to female patients having a higher reporting rate due to cosmetic concerns. Vitiligo commonly begins in young adulthood, with peak onset of about 20-30 years, but it may occur at any age. Although familial clustering of cases is commonly seen, inheritance occurs in a non-Mendelian pattern. Approximately 30% of people with Vitiligo will also have a family member with the disease but the exact mode of inheritance is still yet to be determined.
Clinical features
Vitiligo is characterized by patchy discolorations of the skin in the form of typical white macules due to lack of melanin. Several classification schemes have been proposed for Vitiligo based on the localization of the lesions. The most commonly used classification uses three catergories; general, localized and universal.
Localized
- Focal – lesions are limited to one particular area, most common in the distribution of the trigeminal nerve
- Segmental – lesions develop in patches on one side of the body only or in a dermatomal pattern (corresponds to dorsal root nerves)
- Mucosal – affects mucous membranes only ie. Inside the mouth and the eye
Generalized
- Acrofacial – affects the face and distal extremities
- Vulgaris – Lesions are scattered all over the body with a symmetrical distribution
- Mixed – a combination of acrofacial and vulgaris
Universal
- Over 80% of the body is depigmented
Vitiligo initially manifests during the second or third decade of life as well defined white or hypopigmented macules or patches. These lesions can range from millimeters to centimeters. The most common type is ‘Vitiligo vulgaris’ whilst segmental Vitiligo is rare. The disease progresses naturally over time and is very unpredictable. For example, the lesions could be stable for several years and a sudden exacerbation could occur or a patient with a rapidly progressing case could lose all their pigment within 12 months. Spontaneous repigmentation is likely to happen time from time and localized whitening of scalp hair, eyelashes and eyebrows is frequently observed.
In addition to the different classes of Vitiligo there are a number of clinical variants in the presentation of the disease based on the appearance of the lesion.
- Trichrome Vitiligo - an intermediate zone of hypopigmentation is located between the white center and the peripheral unaffected skin. This results in 3 shades of color; brown, tan, and white—in the same patient
- Inflammatory Vitiligo – the depigmented lesion is surrounded by a raised erythermatous border. It can be present from the onset or develop over time
- Quadrachrome Vitiligo – this reflects the presence of a fourth band around the lesion. It is usually a hyperpigmented band and occurs during spontaneous repigmentation
- Blue Vitiligo – this occurs when the patches develop a blue colouration. It has been observed in patients who have developed Vitiligo after post inflammatory hyperpigmentation
Etiology and pathogenesis
Vitiligo is thought to be a complex multifactorial polygenic disorder with an unknown pathogenesis. Several theories have been put forward but none can completely explain all the features observed. The current accepted theories include:
- Genetic hypothesis
- Autoimmune hypothesis
- Neural hypothesis
- Self-destruction hypothesis and
- Convergence theory
Genetic hypothesis
Observations made suggest that Vitiligo is transmitted via a non-Mendelian mode of inheritance and may involve penetrance, multiple loci and heterogeneity. The inheritance of Vitiligo could involve genes to do with oxidative stress mechanisms, autoimmunity regulation or melanin biosynthesis and degradation. Other studies have revealed that the Human Leukocyte Antigen (HLA) gene is frequently associated with Vitiligo. Many studies are still being completed on the high number of allelic variations of the HLA gene but are thus far inconclusive.
Autoimmune hypothesis
As the association between Vitiligo and some autoimmune diseases has been established, this theory proposes that abnormalities in the immune system lead to the destruction of melanocytes. Thyroid disorders, diabetes mellitus, Addison’s disease, pernicious anemia and Grave’s disease are several autoimmune disorders that have been observed with Vitiligo. The most convincing evidence is the presence of circulating auto antibodies against melanocytes in those with Vitiligo. There are however, many discrepancies with the results obtained from different techniques used to detect the presence of antibodies.
In addition to the involvement of the humoral immune system in the pathogenesis of Vitiligo, there is strong evidence indicating the cellular immune system is involved. Immunohistochemical studies have shown a high abundance of T-cells in the infiltrate found in inflammatory Vitiligo therefore indicating that T cells play a large role in the destruction of melanocytes. Destruction of melanocytes may be directly mediated by melanocytes specific cytotoxic T cells. An increased number of circulating CD8+ cytotoxic lymphocytes reactive to melanoma antigen and tyrosinase has been reported in patients with Vitiligo of active investigation.
Neural hypothesis
Due to the nature of the spread of lesions in segmental Vitiligo, it has been suggested that certain chemical mediators released from nerve endings are cytotoxic to the pigment cells. Some Vitiligo patients have been shown to have mild degenerative or regenerative changes in axons and Schwann cells in the depigmented areas.
Self destruction hypothesis
Melanocytes possess an intracellular protective mechanism to eliminate toxic melanin precursors (e.g. dopa, dopachrome) and free radicals. This theory suggests that in Vitiligo there might be a disturbance of this mechanism, leading to an accumulation of toxic intermediates and free radicals. It has also been found that the erythrocytes of Vitiligo patients have a lower level of glutathione compared to controls. Glutathione has antioxidant properties which indicate that they might experience higher oxidative stress levels. High levels of free radicals lead to lipid peroxidation therefore impairing cell membranes and ultimately lead to cell lysis. It is proposed that this what happens to the melanocytes in individuals with generalized Vitiligo.
Convergence theory
It has been proposed that a combination of factors result in Vitiligo rather than just one, commonly referred to as the convergence theory. The variety of clinical and experimental features along with different family histories suggests that Vitiligo might be the end product of several pathological pathways. It is thought that genetic factors, accumulation of toxic compounds and free radicals, altered cellular environment, autoimmunity and impaired melanocyte function and proliferation can all contribute to Vitiligo. Experts believe that it is highly likely that Vitiligo is a syndrome rather than a single disease.
Prevention
There is no way of preventing Vitiligo even though it is likely to progress. It is very unpredictable in terms of progression which makes treatment difficult. However, systemic steroids may slow the progression down in active patients.
Treatment
The main goal of treating Vitiligo is to improve the appearance of patients, however many are unsuccessful. Although Vitiligo doesn’t cause physical impairments, many patients choose to treat it in order to cope with the emotional distress it causes them. Many therapeutic options exist but treatment challenges persist, as not all patients respond to available therapies and relapse is common. Factors such as the extent, distribution, and progression rate of the depigmentation dictate the choice of treatment.
Treatment includes self care, topical treatments, surgical intervention, and phototherapy.
Self care
There are effective ways for patients to protect their skin and improve the appearance of Vitiligo without medical intervention.
- Minimize sun exposure and ensure that protective clothing and sunscreen are worn whilst in the sun to protect against UV rays
- The use of cosmetics such as make up and tanning lotions to cover up the patches of skin.
Topical treatments
Many of the medical therapies available are applied topically and can reduce the appearance of Vitiligo.
- Topical steroid therapy – steroid creams such as Mometasone furoate may aid in the repigmentation of the patches in Vitiligo but may take up to 2-3 months to have an effect. It does this by suppressing the immune system and possibly slowing the progression of Vitiligo. This treatment can come with side effects such as atrophy of the skin and telangiectasias so doctors may monitor you in case. If there is no clinical response after 3 months then treatment should be discontinued.
- Depigmentation therapy – if a dark skinned individual has Vitiligo that affects large areas of exposed skin, they may choose to undergo depigmentation with bleaching creams containing hydroquinone. It is permanent and causes the skin to lose its pigment.
- Immunomodulators – creams with agents such as Tacrolimus can be used to modulate the immune system at the DNA level. It down regulates the gene expression of certain pro-inflammatory cytokines such as the interleukins and TNF-? to promote repigmentation.
Surgical intervention
Surgical therapies are only recommended for patients with stable Vitiligo, that is, patients whose patches have not grown or spread for at least 6 months. They are usually very costly, can leave scarring and are only considered after other therapies have proven to be ineffective.
- Skin grafts – surgeons can remove skin from the patients own body or from a donor and attach it to an affected area.
- Micropigmentation – manual tattooing of depigmented areas is a cheaper alternative however is it difficult to find an exact match for skin colour. The skin may not remain the same colour as the surrounding skin as it will not naturally change colour based on environmental influences.
- Melanocyte transplantation – still an experimental procedure, doctors will culture normal melanocytes from a sample of the patients skin and transplant them into the depigmented patches.
Phototherapy
Ultraviolet light can be used as a therapy to restore pigment in the skin. Up to 50 sessions of treatment may be needed before the patient sees results. It is also common for the response to be incomplete and relapse to occur. Even is the treatment is successful there is no way of knowing or preventing the patches from extending.
- PUVA – Psolaren plus UV-A radiation. Psolaren (a photo sensitizer) is combined with natural sunlight. It is a moderately effective treatment with a high relapse rate and side effects including: erythema, scaling and rarely, skin malignancies.
- Narrowband UV-B radiation has been shown to be the most effective form of treatment and is associated with the least amount of side effects.
- Targeted phototherapy using an excimer laser at the wavelength of 308nm. Useful for specifically targeting depigmented areas.
Differential Diagnosis
Vitiligo can be mistaken for many other dermatoses with similarities in clinical presentations. These include:
- Tinea versicolor
- Pityriasis alba
- Post-inflammatory hypopigmentation
- Leprosy
- Tuberous sclerosis
- Lichen sclerosis and
- Atrophicus.
To properly diagnose Vitiligo, doctors will need to perform a physical examination and ask about the patient’s general health and family history. To get a better idea of which skin areas have been affected, a ‘Wood's lamp’ may be used on the affected skin in a dark room. Ultraviolet (UV) light from the Wood's lamp causes the skin to appear different colors depending on the underlying condition of the skin. With Vitiligo, there is no pigment and so the skin appears very white. The Wood's lamp allows doctors to see areas affected by Vitiligo that may appear normal under normal light conditions.
Prognosis
The prognosis of this condition is poor as responses to therapy are often unpredictable. Patients generally need emotional support and camouflaging of the depigmented areas and are advised to seek dermatological assessment.
