What is vitiligo and how is it caused?
Vitiligo is acquired depigmentation (loss of pigment) of the skin. It occurs in 1-2% of the population, and is more common in dark races. In 30-40% of cases, it is a familial occurrence. It affects both sexes equally and is detected most frequently at 10-30 years of age.Vitiligo is caused by the death of the cells (melanocytes) producing skin pigment, or melanin, which is responsible for skin color, most often due to autoimmunity.
The result is the appearance anywhere on the body’s skin of growing white areas in various sizes and shapes, usually on the fingers and toes, around the ankles and knees, at the hips, on the back and also on the face around the eyes, ears and in the hair.Many patients have an autoimmune disorder along with it, most commonly a thyroid gland condition. This supports the theory that vitiligo is an autoimmune disease. It is important to note that it is neither contagious nor infectious.The exact cause of the disease is unknown, but there are 3 theories. The most mentioned is autoimmune destruction of melanocytes (pigment producing cells in the skin), which means the immune system recognizes the melanocytes as a foreign body after an attack and tries to destroy them. The underlying cause may be an emotionally stressful situation, trauma, infection (usually viral) or another serious disease. Another theory is based on auto-destruction by the cell’s own enzymatic processes when its cycle is disturbed by oxidative stress. The final theory is aneurohormonal hypothesis that claims melanocytes are destroyed by neurotransmitters - substances involved in transmitting signals between nerve cells. Several agents and factors interact together to cause the disease, so how it appears cannot be clearly explained.