What is Vitiligo?
Vitiligo is an acquired skin disorder characterized by macules (patches) of depigmented (colorless) skin surrounded by areas of normal skin. It is not contagious and generally poses no medical problems.
The depigmented macules result from a complete absence of functional melanocytes (cells that produce melanin, the substance responsible for skin color). Melanin is produced in the epidermis, the top layer of skin. In addition to the skin, patches of hair, mucous membranes (e.g., inside the mouth) and sometimes the retina of the eye may also be affected.
The onset of vitiligo is usually gradual, with the appearance of a few spots. Often, light-skinned people do not notice these macules until spring or summer time, when increased sun exposure causes skin to tan. The loss of pigment may be rapid or gradual. Periods of pigment loss may be followed by periods of stability, a cycle that may continue indefinitely. There also appears to be a link between stress and illness and additional pigment loss.
There is no way to know how progressive a given case of vitiligo may be. In some cases, depigmentation may spread over the entire body. Color may return to the skin spontaneously, but this is rare and typically very limited.
Vitiligo is a relatively common disorder. According to the National Institutes of Health (NIH), it affects 2 to 5 million people in the United States and 40 to 50 million people worldwide. Men and women of all races are affected equally, although the condition is more pronounced in dark-skinned people due to the sharp contrast between affected and unaffected skin. Onset may occur at any time shortly after birth, but the average age of onset is about 20 years, with most cases beginning when patients are in their 20s or 30s. Onset after the age of 40 is very rare.
Types and differences of vitiligo
There have been many attempts to classify different types of vitiligo with varying degrees of success. The results are often conflicting and rather confusing. Two major forms are generally recognized:
- Bilateral. This is the more common form in both children and adults and may be referred to as vitiligo vulgaris. Macules (patches) of depigmented skin occur evenly on both sides of the body.
- Unilateral. Also called segmental, it occurs more often in children than adults. This form of vitiligo usually does not cross the middle part of the body. In fact, macules often stop abruptly at this point.
Generalized is the most common type of vitiligo and includes:
- Vulgaris. Scattered, widely distributed macules on both sides of the body.
- Acrofacial. Macules affecting the extremities (e.g., hands, feet) and the face.
- Mixed. Macules occurring in both localized and generalized patterns.
- Focal. One or more macules in a single area.
- Unilateral (segmental). One or more macules on one portion of the body, stopping abruptly at the midline.
- Mucosal. Macules affecting the mucous membranes (e.g., inside the mouth).
All of these types may involve no functioning melanocytes (cells that produce melanin, the substance responsible for skin color) in the skin at all. In other cases, melanocytes are still present and identifiable in the macules but either do not function or function in a reduced capacity.
There are many variations of vitiligo, including:
- Vitiligo capitis. Vitiligo macules on the scalp. Hair that grows from the affected area lacks pigmentation. Many cases of spontaneous graying in patches of hair have been attributed to this.
- Koebner phenomenon. Sometimes, vitiligo develops at sites of specific trauma (e.g., cuts, burns, abrasions). This is known as Koebner phenomenon and is observed in both bilateral and unilateral forms.
- Trichrome vitiligo. In this variation, depigmented macules are bordered with a zone of a uniform, intermediate hue. Melanocytes in this area are decreased, but not absent.
- Blue vitiligo. Vitiligo with blue colorations, generally developing in areas of darkened skin following inflammation.
- Vitiligo ponctué. An unusual form of vitiligo with small confetti-like or tiny, discrete macules that may occur on otherwise normal or unusually darkened skin.
- Inflammatory vitiligo. An uncommon form of vitiligo with macules surrounded by a border that is inflamed and may be itchy.
- Alezzandrini syndrome. A very rare disorder characterized by depigmentation of the scalp hair, eyebrows and eyelashes, vitiligo macules on the forehead, nose, cheeks, upper lip and skin and vision impairment. This is usually unilateral, with all characteristics occurring on the same side.
How is it diagnosed?
The diagnosis of vitiligo involves a physician taking a medical history and performing a physical examination. Blood tests or other tests are not normally required. In the evaluation of a patient's medical history, a physician will look for certain information, including:
- Whether there is a family history of vitiligo
- Any rash, sunburn or other trauma of the skin two to three months prior to depigmentation
- Any recent stress or physical illness
- Presence of gray hair before the age of 35
- Patient or family history of autoimmune diseases (e.g., thyroid disorder)
- Any increased sensitivity to the sun
Although not usually necessary, a physician may take a skin biopsy from a depigmented macule to rule out other causes of pigment loss. When a patient has vitiligo, there will be no pigment present within the melanocytes (pigment producing cells) when the sample is stained. Blood tests may be performed to check thyroid function and to look for antibodies. A physician may refer a patient to an ophthalmologist (eye physician) for an examination to check for inflammation of certain internal eye structures (uveitis).
How is Vitiligo treated?
Because the process and cause of vitiligo is unknown, there is no known way to prevent the condition. Although difficult to treat, it may be treated by a dermatologist (skin specialist). The goal of treatment is to repigment skin and stabilize the depigmentation process. Aggressive treatment is typically not recommended in children. All patients respond differently to therapy and what works for one may not work for another.
There are many ways to mask vitiligo macules (patches), including:
- Cosmetics. Macules may be hidden or de-emphasized with cosmetics. A physician may recommend cosmetics with sun protection factors (SPF) to help prevent sun damage to depigmented skin.
- Tattooing (micropigmentation). Small macules or those in sites known to have a poor rate of repigmentation (e.g., lips) may be camouflaged by tattooing. However, the color frequently does not match perfectly with the surrounding skin and may fade over the years.
- Bronzers and skin stains. Products that stain the skin (e.g., self-tanning lotions) may be used to camouflage vitiligo macules. The color may not perfectly match surrounding skin, however, and typically fades over a period of weeks.
Topical corticosteroids may be used with other treatments, but may thin the skin or cause dilation of blood vessels. They are not recommended for use on the face. In rare cases, oral corticosteroids may be used to stabilize depigmentation and induce repigmentation. However, these have significant potentials for serious side effects (e.g., loss of bone density), especially long-term use, and use in vitiligo treatment remains controversial.
Immunomodulators (drugs that suppress the immune system) have also been successfully used in very localized areas of vitiligo.
Phototherapy tends to provide the best results, though treatment may need to be long-term. These include:
- Psoralen and long-wave ultraviolet radiation (PUVA). The most common form used for vitiligo. It involves the medication psoralen followed by timed exposure to controlled ultraviolet A light. Psoralen makes the skin very sensitive to light and helps to stimulate melanocytes to divide and fill in areas where pigment was lost. It is usually taken in an oral form, but may be applied topically. However, special care must be taken to avoid severe sun damage with topical applications. Skin cancer is also a potential side effect of PUVA.
- Narrow-band UVB (NB-UVB). Controlled treatment with intense ultraviolet B light is used to induce repigmentation. Advantages over PUVA include shorter treatment times and no need for medications. NB-UVB can be used in children, pregnant or breastfeeding women and people with kidney or liver dysfunction. However, it is not widely available.
- Focused microphototherapy. Ultraviolet B light is shone through a dark pad with tiny holes that is applied to the skin. This can be used to irradiate only the affected skin and results are typically good, but it requires expensive equipment and trained personnel, and is not widely available.
When depigmented macules cover more than half of the body, patients and physicians may chose to depigment the remaining skin. A bleaching agent (e.g., monobenzone) is applied to the normal skin to match it with the depigmented skin. However, the patient’s appearance is significantly altered and the skin is made much more sensitive to sun damage. Many patients are allergic to the bleaching agents, so tests must be performed before widespread application. Side effects include contact dermatitis.
Medications (topical form)
About 30% of people affected with vitiligo undergo a spontaneous repigmentation. Intensive phototherapy has resulted in repigmentation in more that 50% of cases. Otherwise, mild cases are disguised with cosmetics, while extensive cases can be made less noticeable by chemically bleaching the surrounding skin.
Leukoderma has a similar presentation.
Last updated 30 June 2015