Vitiligo: Signs and Symptoms

Vitiligo is a disorder of the skin and its chief presentation is the depigmentation of the skin and the appearance of white patches of macules on the skin.

This skin disease is caused by the progressive destruction of melanocytes of the skin.

Melanocytes are the cells of the skin responsible for producing melanin which is the natural pigment that gives the skin its color. Melanocytes are activated by sunlight. The tan and other darkening of the skin when it is exposed is as a result of increased melanin production.

Vitiligo affects about 1% of the world’s population. It usually first presents around the age of 20 (and in majority of cases, before the age of 40) and it is equally found in both sexes and all races.

Causes of Vitiligo

There is no agreement on what exactly causes vitiligo. However, it is most likely caused by multiple factors working together.

The most popular theories regarding the cause of vitiligo are:

Autoimmune Attack: This theory asserts that vitiligo arises when the melanocytes are progressively destroyed by the cells of the immune system.

There are clinical supports for this theory including evidences for the participation of both cellular and humoral immunity in the destruction of melanocytes. For example, antibodies and melanocyte-targeting T-cells have been seen freely circulating in melanocyte patients and in their vitiligo lesions too.

The autoimmune cause of vitiligo is also believed to be the reason the skin disorder presents with other autoimmune diseases in some people.

Examples of autoimmune diseases associated with vitiligo include thyroid disorders (Hashimoto thyroiditis and Graves’ disease; diabetes mellitus; alopecia areata; pernicious anemia; psoriasis; and inflammatory bowel disease).

Intrinsic Defect in Melanocytes: Malformed melanocytes are more likely to be destroyed than normal melanocytes. Therefore, this theory states that vitiligo is caused by the early death of naturally defective melanocytes.

Oxidative Stress: Oxidative stress on the skin results from the exposure of the skin to environmental toxins including phenolic chemicals as well as the increased production of harmful free radical and hydrogen peroxide in the skin.

Naturally, the skin copes with this stress through antioxidant enzymes such as catalase.

However, when the oxidative stress overwhelms the antioxidant removing these toxins or when the production of antioxidant enzymes fall off, the melanocytes are open to quick destruction by free radicals.

In fact, measuring the level of catalase in the skin is one of the diagnostic tests for vitiligo. Another test is the yellowish green or bluish fluorescence of vitiligo skins which is caused by oxidized pteridines and an indication of the accumulation of hydrogen peroxide in the melanocytes.

Neural Damage: Some vitiligo cases arise only after the patients suffer some form of nerve damage. Therefore, some experts believe that the cause of melanocyte death in these cases is the changes in neurochemicals released at nerve endings.

Genetics: Genes have also been shown to play some part in the appearance and progression of vitiligo.

For example, about one-third of vitiligo patients have other members of their families with the same condition and 5 – 7% of vitiligo patients directly inherit the skin disorder from their parents.

There are multiple genetic variations that can contribute to the development of vitiligo. Genes that determine the regulation of the immune system, the production of melanin and the body’s response to oxidative stress can all determine whether and even when people develop vitiligo.

Signs and Symptoms of Vitiligo

The most important signs and symptoms of vitiligo are the white patches that appear on the skin.

Vitiligo patches are not sore, infected or even itchy. In very rare cases, vitiligo may affect retinal pigment. However, both impairment of vision and changes in color perception are too rare for consider as symptoms of vitiligo.

Due to the nature of the white patches, the areas of the skin affected by vitiligo are more susceptible to sunburn since there is far less melanin to absorb most of the ultraviolet rays of sunlight. For this reason, sunscreens are recommended for vitiligo patients.

Besides physical symptoms, vitiligo can also cause psychological distress due to the changes in the appearance of the skin. This emotional symptom is most common in women and teenagers.

Such psychological distress could lead to depression and other mood disorders. Therefore, it should be treated alongside the other symptoms.

Vitiligo Lesions: Appearance

Vitiligo lesions are also described as amelanotic macules. They appear as chalky or milky white patches first as the extremities.

These macules are usually demarcated from pigmented skin. Therefore, they form sharp contrasts with normal skin in dark-skinned people. Vitiligo lesions may not be easily discernible in light-skinned people but it can be easily observed with a Wood lamp examination.

Vitiligo macules are found in hypopigmented areas of the skin (where the skin color is being lost due to the destruction of melanocytes).

They appear as linear, round or oval with convex borders.

Vitiligo Lesions: Distribution

Although they can be found in any part of the body, vitiligo lesions first appear on the face, scalp, neck, hands, forearms and feet.

Most of these sites but especially the limbs are subjected to repeated trauma through everyday use. The wrists, hands, forearm and fingers are almost always in touch with other things in the environment and these repeated exposures serve to increase the likelihood of increased melanocyte destruction.

Vitiligo patches may also be found on mucosal membranes as well as around body orifices such as the lips, genitals, gingiva, nipples, navel and rectum.

When they appear one the face, vitiligo lesions usually concentrate around the eyes and mouth.

The hair growing in areas affected by vitiligo patches may also turn white. This is most evident when vitiligo affects the scalp. However, this effect can also cause white eyebrows and pubic hair.

By distribution, vitiligo can either be classified as localized or generalized. Localized vitiligo is restricted to one area of the body e.g. mucosal membrane or the face.

Generalized vitiligo, on the other hand, can be found widely distributed and even involving various local vitiligo appearing in different parts of the body. It can also be symmetrical or asymmetrical.

Asymmetrical vitiligo refers to the occurrence of the similar vitiligo patches on the same part of each half of the body e.g. white patches of similar shape and size appearing on the wrist of both arms.

Vitiligo Lesions: Progression

The sizes of vitiligo patches vary from a few millimeters to centimeters.

There is no way to determine if and how fast these patches will expand. When vitiligo patches expand, the patches enlarge centrifugally (out from the center) and grow both in size and shape. As their borders widen, the tan zone between depigmented and pigmented areas are turned chalky white.

By progression, vitiligo can either be classified as segmental or non-segmental. Segmental vitiligo appears early in life and it spreads rapidly. The vitiligo macules formed during the expansion of segmental vitiligo can remain unchanged and permanently depigmented.

Vitiligo Lesions: Color

The usual vitiligo lesion is made up of concentric zones of different colors.

A typical vitiligo lesion has 3 colors corresponding to 3 zones: achromia (white color; the center of the lesion), hypochromia (tan color; surrounding the center) and pigmented skin (unaffected skin at the edges of the lesion).

As the lesion grows, the hypochromia zone soon loses its color and becomes fully depigmented.

However, there are variations to this trichrome vitiligo. Quadrichrome and pentachrome vitiligo are similar to trichrome vitiligo but with extra color zones.

In rare cases, the edge of vitiligo lesions may be marked by red, inflamed borders which are accompanied by mild itching.

Redness may also be associated with a form of vitiligo called Koebner phenomenon. This is caused by physical injury to the skin. Such trauma includes cuts, burns and abrasion.

Lastly, there is blue vitiligo which is only seen in patients who develop vitiligo following hyperpigmentation and inflammation of the skin.

Vitiligo and Other Diseases

Eye Diseases: Although vitiligo does not change the color of the irises, more than 1 in 3 vitiligo patients have part of their pigment epithelium depigmented. Inflammation of the iris may also occur in about 5% of vitiligo patients.

Overall, the inflammation of the uvea (the part of the eye containing the iris and choroid which are responsible for eye color) is the most important ocular complication of vitiligo.

Ear Diseases: Because melanin is essential to auditory function, vitiligo can cause complications in the ear. Melanocytes are found in the inner ear and melanin contributes to the conduction of auditory signals in the inner ear.

Studies have placed the incidence of auditory complications at 16% of vitiligo patients.

Thyroid Dysfunction: Of all autoimmune diseases associated with vitiligo, thyroid dysfunction is the most commonly associated with vitiligo. Usually, the vitiligo appears before the thyroid disease. Therefore, young vitiligo patients are usually screened for thyroid abnormalities.

Melanoma: Vitiligo depigmentation may occur in patients with malignant melanoma. The white patches of this kind of skin cancer can even occur at body parts far from the site of melanoma.

It is believed that both the melanoma and vitiligo are caused by T-cells of the immune system.

Treating the Symptoms of Vitiligo

Vitiligo treatment options are usually directed at stopping the expansion of vitiligo lesions and even reversing the depigmentation of the skin as long as less than 50% of the body surface is affected.

When the vitiligo breakout is mild, some people use camouflaging agents such as make-ups and self-tanning lotions. Homemade cover creams can also be used. These are made by mixing food coloring with rubbing alcohol.

To repigment the white patches of vitiligo, steroid creams are also applied on the skin. However, because of their extensive side effects, safer topical agents such as tacrolimus and pimecrolimus are also used.

Light therapy is also another option for treating vitiligo symptoms. PUVA (psoralen and ultraviolet A therapy) was once the light therapy of choice. Currently, narrow band UVB (ultraviolet B light) is used. UVB is safer, with fewer complications, does not require photosensitizing drugs such as psoralen and has a shorter treatment session.

Excimer laser is another new option in light therapy. It is new and expensive.

Surgery can also help repigment vitiligo patches. Autologous skin grafting is one such surgical procedure. It involves taking some normal skin and grafting them over vitiligo patches.

Alternatively, autologous melanocyte grafting is another surgical option. It involves taking melanocytes from normal, pigmented skin which can then be grown and multiplied under laboratory conditions before they are transplanted on white patches.