Causes of vitiligo
The lack of color in these areas characteristic of vitiligo is due to the disappearance of melanocytes . Melanocytes are cells that make melanin, which is the substance that gives color to hair and skin. The cause of this disappearance is unknown. Currently there are several theories to explain it, but there is no concrete evidence to support any of them:
- Autoimmune theory: the patient’s own immune system recognizes melanocytes as a threat and eliminates them. Currently it is the most solid theory, especially in generalized vitiligo, due to its association with other autoimmune disorders such as diabetes , thyroiditis, ankylosing spondylitis, and so on.
- Neurogenic theory: in the nerve endings is released some substance that is toxic to the cells that give color to the skin. This theory is supported in cases in which the depigmentation is distributed only by a dermatome (area of skin that receives nerve endings from a root of the cord). It would be segmental vitiligo.
- Theory of self-destruction: the melanocytes destroy themselves, it is believed that by excess of function or by an inability to eliminate the toxins derived from the metabolism of the skin cells accumulating and becoming toxic to the melanocytes.
All these mechanisms can also occur at the same time and explain some cases of vitiligo, forming an integrating theory , as many specialists in dermatology postulate.