Why occurs ?
In vitiligo degrades pigment cells and not yet entirely clear what the precise mechanism is induced damage to these cells. Therefore, the causes of vitiligo are not yet fully specified. It is considered part of the complex factors and mechanisms. Created different theories and hypotheses why vitiligo occurs, but none of these theories provides a complete answer why vitiligo occurred in every case. Recent years accumulated data and that in addition the cells which form the skin pigment in vitiligo changes occur in the other cells of the superficial layer of the skin - ie. keratinocytes.
The main theories of onset of vitiligo are:
In vitiligo have often combined with certain genetic polymorphisms: HLA-DR4,-Dw7,-DR7,-DR1,-B13,-Cw6,-DR53,-A19. Found mutations and signals in different chromosomes - 1st, 2nd, 7th, 8th, 11th, 17th, 19th, 22nd.
People with vitiligo inherit a set of genes upon exposure to various triggers such as stress, trauma, burns, and other unlocked condition.
Genetic theory is supported by the fact that in some families has increased the incidence of autoimmune disease, due to what is believed to be inherited called. increased susceptibility to autoimmune diseases.
Studies conducted in the vitiligo confirmed, as the role of cellular and humoral immunity.
In support of the role of immunity and the fact that immunotherapy melanoma - malignant tumors of the skin, which is formed of pigment cells in the skin can appear white spots. Furthermore, in the treatment of the disease vitiligo successfully using means which alter the immune response such as corticosteroids, UV light, cytotoxic drugs.
Studies on the role of oxidative stress are supported by a number of changes in the skin and into the blood of the people who have vitiligo. In the skin are detected elevated levels of hydrogen peroxide and reduced levels of catalase, but in the blood has low levels of catalase and glutathione and increased levels of superoxide dismutase and xanthine oxidase.
According to this theory, vitiligo occurs when melanocytes are formed large amounts of cytotoxic quinones - substances which are precursors of melanin.
Auto Cytotoxic theory explains how vitiligo occurs during industrial workers exposure to the effects of catechol, phenols and sulfhydryl groups - substances which are contained in the chemical and cleaning agents.
The existence of neurogenic theory is supported by the existence of a segment vitiligo. In this form of vitiligo changes are localized in certain skin segments.
There is evidence of the involvement of other virus - herpes simplex virus (HSV).
Based on these data is created and the hypothesis of involvement of viral infection on the occurrence of vitiligo.