What is Vitiligo? What does the illness consist of?
It is an acquired dermatological complaint, consisting in the partial or total loss of melanocytes, the cells responsible for the pigmentation of the skin and other body organs and tissues. Therefore, clinically it appears as a circumscribed loss of colour, in the form of milky-white patches, which may appear in one or several areas of the skin. It is a non-infectious process, with no pain or itching and, in most cases, the other vital functions remain unaffected.
What disorders or pathologies appear in Vitiligo patients? Are there different forms of marks?
In 15-20% of cases, this type of leucoderma appears together with other disorders, such as diabetes mellitus, pernicious anaemia, alopecia areata, thyroid problems (hyper- and hypothyroidism), psoriasis, etc. Moreover, recent studies carried out on human melanocyte cultures appear to indicate that it affects the pigmentary system in general, not just the skin, affecting even cellular elements of the nervous system that contain melanin.
The maculas come in extremely variable shapes and sizes, from several millimetres to several centimetres. Sometimes they change size irregularly and join with bordering lesions, forming more complex patterns. Their shape is generally round or oval. The margins are clearly visible and are often hyper-pigmented.
Since when has this disease been known and how is it known in other cultures?In ancient times, this disorder was known by many different names: SHWETAKUSHTA in the ATHARVA VEDA, the sacred book of India (1400 BC); the words BOHAK and BARAS are used in Arabic. The word Vitiligo is probably derived from the Latin word VITIUM (stain) and the suffix IGO.
It would appear that in ancient time Vitiligo was sometimes confused with leprosy. Why did this confusion arise?
The biblical references to this type of leucoderma go back to the translation of the Hebrew word ZORAAK (Leviticus 13.2) by the Septuagint scholars in the year 250 BC. Leprosy pandemics in the Middle Ages and abundant myths and historical confusion have, even in recent times, particularly in underdeveloped countries, led to vitiligo sufferers being called lepers.
A DISORDER THAT AFFECTS MILLIONS OF PERSONS, MAINLY IN THE WARMER AREAS OF THE WORLD
What is the general frequency of vitiligo, statistically speaking?
The disorder is considered to be widely distributed and to affect millions of persons. The frequency varies between 1-2% of the population in the western world, and 5-8% in other regions, where the incidence is higher, such as in the Middle East, Northern Africa and South-East Asia. In these areas, we can observe that, in addition to the aesthetic problem derived from the contrast between the pigmented and non-pigmented areas of the skin, there is a marked psychosocial aspect, leading to personal or even professional marginalisation of the sufferers.
Is vitiligo more frequent in men, women or children? Does it have any preferences as regards sex, age, race, countries, professions, social class, climate or type of country?
This illness has no definitive preferences as regards age, sex, race, profession or social class. The only thing I can say, in my experience, is that most patients are between 15-40 years of age. Likewise, there is a higher incidence in the warmer parts of the planet.
Is the real cause of the disease known? Occasionally, although it is not a contagious disease, several members of the same family might have it. Could it be considered a hereditary disease?
The etiology of human vitiligo is unknown. After analysing recent research, we can affirm that the syndrome probably responds to several, mutually tolerant, etiologies. I would like to point out that, in studies carried out on animals, de-pigmentation was observed to have a genetic component, related with intrinsic defects in the melanocytes; these defects may also be exacerbated by the immune system. In the case of humans, no hereditary factor has been established. It is true that it often appears in several members of the same family, allowing us to observe a family predisposition; however, in at least 60% of cases, no direct family members are affected, so we can reasonably conclude, as affirmed in a recent work published by Professor J.J. Nordlund of the University of Cincinnati, that there may be genetic factors involved, but the transmission model is complex, compatible with a polygenic disorder. Personally, I think that there are still matters remaining to be solved.
AN AUTOIMMUNE DISORDER CREATED BY THE DEFENCES OF THE AFFECTED PERSON
Vitiligo is considered an autoimmune disorder. What does this mean?
The argument that the melanocytes are destroyed by lymphocytes, by cytotoxic antibodies, or both, has been verified by many specialists in the matter. Therefore, the immune system appears to play a fundamental role in the pathogeny of vitiligo. We are dealing therefore with an autoimmune disorder, created by the defences of the affected person. This theory is based, among other reasons, on the observation of circulating anti-melanin antibodies, detected in skin lesions, and in the concomitancy of vitiligo with other autoimmune disorders that we have mentioned earlier, including thyroid problems (hyper- and hypothyroidism), liver problems, diabetes, alopecia aleata, etc. We could also point out that, in some cases the antibodies could exacerbate the intrinsic defects of the melanocytes and kill them, as ahs been observed in animals, backing up the theories that vitiligo etiopathogeny are not exclusive.
Many patients relate nervous or emotional problems with the onset of the disorder. Is there any connection between psychological traumatism and the illness itself?
The theory that the nervous system intervenes in some way in the pathology of vitiligo is actually backed by a lot of data. We could point out that the melanocytes are embriologically related to nerve cells; they both originate from the neural crest and are morphologically similar. Moreover, some studies indicate that the concentration of certain neural transmitters is abnormal when the skin is de-pigmented. Likewise, although I have already stated that there are reasons to believe in an immunogenic cause for the depigmentation of the skin, however, experts frequently associate the main catalyst for this “exaggerated” response of the immune system with some nervous disorder. Effectively, many patients relate some emotional disorder with the onset of the illness. This traumatic-psychological episode may have caused the release of certain neuromediators toxic to melanocyte, which, on breaking up, frees the antigens, which, under certain conditions, set off the autoimmune process.
You have already commented that this complaint is not exclusive to humans, that it may exist also in animals. Are there different types of human vitiligo?
We treat different manifestations of vitiligo in accordance with the location of the spots, which may affect a small area, or spread over many parts of the skin. Localised vitiligo may be focal, with one or several patches in a single area; segmental, one or more macules in a semi-dermatomal pattern; or mucosal, restricted to the mucous membranes alone. Generalised vitiligo may be acrofacial, affecting the distal extremities and the face; or vulgaris, consisting of scattered macules. This latter type may evolve into universal vitiligo, where depigmentation is complete or almost complete.