What is Vitiligo?
Patients with Vitiligo develop white spots in the skin that vary in size and location. The spots occur when pigment cells, or melanocytes, are destroyed and the pigment melanin can no longer be produced. Melanocytes normally occur throughout the skin, and in the hair follicles, mouth, eyes, and some parts of the central nervous system. In Vitiligo, pigment cells can be lost in any of these areas. Common sites of pigment loss are:
- Exposed areas: hands, face, upper part of the chest
- Around body openings: eyes, nostrils, mouth, nipples, umbilicus, genitalia
- Body folds: arm pits, groin
- Sites of injury: cuts, scrapes, burns
- Hair: early greying of hair of the scalp, beard or other areas
- Area immediately surrounding pigmented moles
- Choroid of the eye
Melanin is the substance that normally determines the colour of skin, hair, and eyes. This pigment is produced in cells called melanocytes. If melanocytes cannot form melanin or if their number decreases, skin colour will become lighter or completely white as in Vitiligo.
Leukoderma is a general term that means white skin. Severe trauma, like a burn, can destroy pigment cells resulting in leukoderma. Vitiligo is just one of the forms of leukoderma.
The beginning of Vitiligo and the severity of pigment loss differs with each patient. Light skinned people usually notice the pigment loss during the summer as the contrast between the vitiliginous skin and the suntanned skin becomes distinct. People with dark skin may observe the onset of Vitiligo at any time. Individuals who have severe cases will lose pigment over their entire body surface. There is no way to predict how much pigment an individual will lose, Illness and stress can result in more pigment loss. The degree of pigment loss can also vary within each Vitiligo patch, and a border of abnormally dark skin may encircle a patch of depigmented skin.
Vitiligo frequently begins with a rapid loss of pigment which may be followed by a lengthy period when the skin colour does not change. Later, the pigment loss may resume perhaps after the individual has suffered physical trauma or stress. The loss of colour may continue until, for unknown reasons, the process stops. Cycles of pigment loss, followed by periods of stability may continue indefinitely. It is rare for a patient with Vitiligo to repigment or regain skin colour spontaneously. Most patients who say that they no longer have Vitiligo may actually have become depigmented and are no longer bothered by contrasting skin colour. While such patients appear to be “cured”, they really are not. People who have Vitiligo all over their bodies do not look like albinos because the colour of their hair may not change or it can be dyed and eye colour does not change.
To get repigmentation, new pigment cells must be produced from existing ones. That means that new pigment cells must come from the base of hair follicles, from the edge of the lesion or from the patch of Vitiligo itself if depigmentation is not complete. The maximum amount of repigmentation that can be expected in any one spot in a year of treatment is an eighth to a quarter of an inch. If in a given area most of the hair follicles would provide pigment cells that radiate to one eighth to a quarter of an inch, there could be marked repigmentation. However, if the hairs are white or if there are no hairs, repigmentation must occur from the edge.
In repigmentation therapy, a patient is given a psoralen drug and then is exposed to ultraviolet light A (UV-A). When psoralen drugs are activated by UV-A, they stimulate repigmenation by increasing the availability of colour-producing cells at the skin’s surface. The response varies among patients and body sites.
The psoralen drugs used for repigmentation therapy are trimethylpsoralen and 8-methyoxypsoralen. A patient takes the prescribed dose by mouth two hours before lying in the sun or under artificial ultraviolet (UV-A) light. The ideal time for natural sunlight is between 11 AM and 1 PM when the sun is highest. Treatment every other day is recommended. Too much ultraviolet light can be harmful.
Treatment schedules can be adjusted for each patient. If the day is cloudy or if sun exposure is not possible on a scheduled treatment day, then the patient does not take any medication because the drug does not work without appropriate sunlight. In the northern part of the United States, patients usually begin therapy in May and continue until September. Moderate repigmentation should take place during this time.
Treatment is usually discontinued during the winter. This rest period is desirable so that patients do not tire of continual treatment. Artificial sources of UV-A light can be used throughout the year, but patients should consult their dermatologist to determine whether such treatments are accessible and desirable. UV-A light systems for home use are expensive and treatment with them time consuming. Ordinary sunlamps are not effective with the psoralen medications. Only UV-A light produces the desired interaction. A dermatologist’s supervision is required during all aspects of repigmentation therapy.
Patients with Vitiligo should always protect their skin against excessive sun exposure by wearing protective clothing, staying out of the Sun at peak periods except during treatment time, and/or applying sunscreen lotions and creams. Sun protection products are numbered according to the sun protection factor (SPF), with the higher numbers giving more protection. Patients with Vitiligo should use a sunscreen with an SPF of 1 5 or higher, except during the hours of treatment. During treatment, an SPF of 8 to I 0 protects against sunburn but does not block the UV-A needed for treatment. Sunscreens should be reapplied after swimming or perspiring. To prevent potential damage to the eyes, special sunglasses with protective lenses should be worn during sunlight exposure and for the remainder of the day on which the psoralen drug was taken. Another method of psoralen treatment, used occasionally for patients with small, scattered Vitiligo patches, involves the application of a solution of the drug directly to t he affected skin area. This is then exposed to sunlight. Such topical treatment makes a person very susceptible to severe burn and blisters following too much sun exposure.
Hydrocortisone-type compounds when applied to the skin slow the process of depigmentation and sometimes even enhance repigmentation. The weak Hydrocortisones that are sold over the counter, such as 0.5% hyrocortisone, are too weak to help. The very potent Hydrocortisones when used daily for a long-time produce side effects, such as thinning of the skin. Under the care of a dermatologist it is usually possible to adjust the treatment with topical hydrocortisones so that side effects are at a minimum.
All patients are not good candidates for re-pigmentation. The ideal person for this therapy should meet these requirements:
Pigment loss of less than five years duration for patients over 20 years of age. In general, children and young adults respond better than older people.
Patients should be at least 10 years old. Treatment is safe for younger children, but because the method is tedious, better results are achieved when the child is interested in treatment. An individual must be committed to the treatment because it is a long process that requires a great deal of patience.
Patients should be healthy. No one with a sensitivity or allergy to sunlight can be treated. Any associated illness, such as hyperthyroidism, should be treated at the same time as the Vitiligo.
The patient should have the opportunity to be exposed to sunlight for one or two hours three times a week during the summer months for a period of two to five years.