Impetigo, commonly known as school sores, is a bacterial skin infection. It is characterised by itchy,…
What is vitiligo?
Vitiligo is a skin condition in which loss of skin colour (pigment) causes white patches to develop on the skin. Any part of the body may be affected, but it most commonly appears on exposed areas of skin, around the armpits and groin, at injury sites or around moles.
While vitiligo can occur in people of all ethnicities, it is often more noticeable in people with darker skin. It can also start at any age, but tends to first appear between the ages of 10-30 years. Vitiligo is not an infection and cannot be passed on from one person to another.
Vitiligo occurs when melanocytes in the skin are damaged or destroyed. Melanocytes are cells that produce melanin, the pigment responsible for determining the colour of your skin, hair and eyes. The characteristic white patches of vitiligo occur when there are very few or no melanocytes producing melanin in an area of skin. Vitiligo is not caused by an infection and is not contagious.
While it is not known exactly why melanocytes are lost from the skin, some proposed causes include:
The immune system may mistakenly attack melanocytes, as if fighting infection or healing a wound. This damages the melanocytes and causes absence of melanin in affected areas of skin. Vitiligo can also be associated with other autoimmune conditions, such as Addison's disease, hyperthyroidism, vitamin B12 deficiency (pernicious anaemia) and a particular type of hair loss, known as alopecia areata.
Defective nerve cells in the skin release toxic substances or neurochemicals that harm nearby melanocytes. This process may result from continuous friction or injury to the skin.
Another theory is that melanocytes may destroy themselves due to unknown reasons. This self-destruction is known as an autotoxic response.
Given that vitiligo tends to run in families, certain genetic factors passed on from parents to their children are thought to make melanocytes more vulnerable.
Several factors are known to trigger vitiligo without directly causing it. For example, vitiligo may occur after physical or emotional stress, childbirth, exposure to certain chemicals, cancer of the melanocytes (melanoma), or a skin injury such as a cut or severe sunburn. Vitiligo appearing at the site of an injury is known as the Koebner response.
Risk factors that increase the likelihood of developing vitiligo include:
Vitiligo may be classified into the following types:
Non-segmental vitiligo (NSV) is the most common type, affecting both sides of the body in a symmetrical pattern. For example, it may develop on both of the hands or knees. In its early stages, NSV often appears on the backs of the hands, arms, elbows, feet or knees. It may start with a rapid loss of skin colour, followed by a period of inactivity, then further colour loss. As this cycle continues over time, white patches become larger and more noticeable.
Segmental vitiligo (SV) describes white patches that usually only occur on one area of the body, such as a leg or the face. Some people with this type of vitiligo may also lose colour in the hair of the scalp, eyebrows, eyelashes or beard. SV often begins at an early age, progresses for about a year and then stops.
While quite rare, mixed vitiligo involves a combination of non-segmental and segmental vitiligo symptoms.
The unclassified description is used during early stages of vitiligo when symptoms are still developing.
Signs and symptoms
Vitiligo usually first appears as a few small white patches that may then spread over several months. It can occur on any part of the body, but usually begins on the hands, feet, forearms and face. Vitiligo can also affect the eyes, ears or linings of the mouth, nose, rectum and genitals.
It is hard to predict how vitiligo symptoms will progress. In some people, the characteristic white patches grow and spread, but stay in the one area for a number of years. However, it is also possible for symptoms to shift and change over time as areas of skin lose and then regain colour. Symptoms can also range from one or a few white patches to a widespread loss of colour.
In general, symptoms may include:
- Flat, white patches of skin with well-defined but irregular edges;
- Slightly pink areas when there are blood vessels under the skin;
- A border of darker skin surrounding the lighter skin;
- Early greying or whitening of hair in the scalp, eyelashes, eyebrows or beard;
- Cycles of colour loss, followed by stability;
- Greater contrast during summer months when lighter skin can be tanned, and;
- Different shades of brown within a vitiligo patch (trichrome vitiligo).
These symptoms aside, vitiligo doesn't cause other signs of illness or skin changes, such as dryness or soreness. However, affected skin may occasionally be itchy and the lack of colour makes sunburn more likely.
Methods for diagnosis
Your doctor will usually diagnose vitiligo by examining the skin and asking questions about your personal and family medical history. To confirm the diagnosis, your doctor may also use a handheld ultraviolet (UV) light, known as a Wood's light, which makes white areas of vitiligo glow in the dark.
Sometimes your doctor may also take a small skin or blood sample to rule out other causes or check for autoimmune conditions. If the eyes are affected by vitiligo, you may be referred to an eye specialist (ophthalmologist) for further tests.
Types of treatment
As there is no known cure for vitiligo, treatment aims to improve the skin's appearance by restoring colour or making symptoms less noticeable. However, if vitiligo symptoms are of little concern or are not visible to others, treatment may be avoided altogether. Options for treatment may include:
To help protect against sunburn and skin damage, it is recommended that you cover your skin when outdoors, stay out of the sun and use sunscreen with a sun protection factor (SPF) of 30 or higher.
As sunlight is the body's main source of vitamin D, you may be prescribed supplements to avoid problems arising from reduced exposure to sunlight.
To hide symptoms of vitiligo, your doctor may recommend a special camouflage cream made to match your skin tone. These creams are usually waterproof, last for hours and can be applied to any area of the body. Some creams may also contain sunscreen for added skin protection. Similarly, self-tanning products may also be used to help cover vitiligo.
To block the autoimmune response thought to cause vitiligo, your doctor may prescribe a corticosteroid cream, such as betamethasone, hydrocortisone or fluticasone. These medications can prevent the spread of white patches or even restore natural skin colour in some people.
However, corticosteroids can cause side effects, such as thinning of the skin, acne or a red skin rash. For this reason, they are usually only prescribed for less than three months at a time, when sun protection and skin camouflage measures have not helped. Corticosteroid creams are not recommended for sensitive areas, such as the face and neck.
Also known as calcineurin inhibitors, these medications may be particularly useful for treating vitiligo on the face and neck, where corticosteroid creams are not usually used. These medications may restore skin colour, possibly by blocking the autoimmune response thought to cause vitiligo. Immunosuppressant creams used to treat vitiligo include tacrolimus and pimecrolimus.
Also known as phototherapies, these treatments are only recommended when symptoms are widespread, or previous treatments have not worked. Used alone or together with medications, these treatments are designed to restore skin colour through the use of artificial light. Types of light therapies used for vitiligo include:
Narrowband ultraviolet B therapy
Narrowband ultraviolet B (UVB) therapy involves controlled application of UVB light to the skin from an artificial light source. As the light is delivered at a narrow wavelength, it can be targeted to a very small area of vitiligo. Treatment usually involves two sessions per week and may be given together with immunosuppressant medication.
Photochemotherapy involves administration of a light-sensitising medication, psoralen, prior to application of ultraviolet A (UVA) light. As UVA light is delivered at a longer wavelength than narrowband UVB light, it is not as targeted but can reach deeper into the skin. It is most effective on the face and body rather than on the hands and feet.
During PUVA treatment, light is applied for a few minutes using a specialised machine at a hospital or clinic. The treatment is usually given twice a week for up to two years. Treated patches turn pink at first and then begin to return to original skin colour as they heal. Side effects can include sunburn, blistering, itching, or areas of skin turning particularly dark.
Excimer laser therapy
A device, known as an excimer laser, can deliver a narrow wavelength of UVB light to a very precise area of skin. Excimer laser treatment is often given together with cream medications. Possible side effects may include redness and blistering.
In some cases, a surgical procedure at a specialised clinic may be suggested to reduce the appearance of vitiligo. Surgical treatment options might include:
Skin grafting surgery involves taking normal skin from one area of the body and using it to cover a patch of vitiligo. A number of techniques may be used for removing the skin, including dermabrasion, laser treatment, a skin punch, or blistering using suction or dry ice (liquid nitrogen). Possible side effects include pain, infection or temporary development of skin patches that are particularly dark or light.
Tattooing may be suggested by your doctor as a method for returning colour to the skin, particularly around the lips or in people with dark skin. Also known as micropigmentation, the procedure is conducted with a specialised surgical instrument. Tattooing procedures are generally recommended when the spread of vitiligo has stabilised.
Another surgical procedure, known as autologous melanocyte transplant, involves taking a sample of normal skin and using it to grow new melanocytes in a laboratory. These melanocytes are then transplanted to areas of skin affected by vitiligo, where they begin to produce new melanin. However, this treatment is not widely available and is usually expensive.
For dark skin or when large areas are affected by vitiligo, depigmentation therapy may be an option. This treatment involves applying a medication called monobenzene ester of hydroquinone to normal skin. This medication reduces the amount of pigment, so that unaffected skin becomes the same colour as areas of vitiligo. Possible side effects may include redness, swelling and ongoing sensitivity to sunlight. As depigmentation therapy is permanent, this option is usually only recommended if other treatments have not worked.
While vitiligo does not develop into other conditions, it may lead to the following complications:
Due to a lack of melanin, people with vitiligo are at increased risk of sunburn. White skin affected by vitiligo does not tan; it can only burn. Similarly, exposing unaffected skin to sunlight can cause vitiligo to spread or become more noticeable.
As vitiligo often affects exposed skin over a long period, the condition may lead to psychological issues, such as embarrassment, social withdrawal, low self-esteem or depression.
Vitiligo is unpredictable and affects people in different ways. Young people with stable vitiligo on the face usually have the best chance of regaining skin colour. Vitiligo that appears later in life on the limbs, hands and lips is less likely to respond well to treatment. A stage of colour loss may be followed by a stable period where the skin does not change. These cycles may continue for life.
Treatment outcomes are also variable. For example, treated skin may be lighter or darker than normal skin, or it may respond differently to sunlight. Even when treatment is successful, symptoms may reappear later in a treated or untreated area. However, as vitiligo does not cause pain or develop into other conditions, treatment may not be required if symptoms do not cause distress.
There is no known way to prevent vitiligo from developing or progressing. However, various treatments may improve the skin's appearance by restoring colour or making symptoms less noticeable. Protecting affected skin from sunlight may help to prevent sun damage.