What Causes Vitiligo?

What causes vitiligo? 

Key points 

• The cause of vitiligo is unknown. 

• There are different types of vitiligo. 

• The different types could have different origins and causes. 

• The most widespread forms of vitiligo seem to be related to the immune system disorder with production of  antibodies against melanocytes. Life stressing events, infections, and the accumulation of toxic compounds in  the body are under investigation. 

• The limited forms of vitiligo seem to be related to alteration of skin nerves. 

• The autoimmune hypothesis is the best documented theory: it seems that the immune system reacts against the  cells which produce melanin pigment. 

• The neurohumoral, cytotoxic, and oxidative stress theories have moderate evidence (All medical terms will be  explained in the following pages.) 

• New theories focus on melanocytorrhagy – i.e. melanocytes are discharged by the skin – and on decreased  melanocyte survival in the skin. 

Answer 

It remains unclear what causes damage to  melanocytes and their subsequent total  inactivation and/or disappearance in vitiligo  skin. There are several theories; the most  prominent are autoimmune, neurohumoral, related  to abnormal detachment of melanocytes from the  epidermal layers and autocytotoxic. None are  mutually exclusive, and it is likely that each of  them partially contribute to the disease  development. 

The current thought is that vitiligo represents a  group of different disorders with a similar  outcome: the appearance of white patches on the  skin. 

The convergence theory states that stress,  accumulation of toxic compounds, infections,  autoimmunity, genetic predisposition, altered  cellular environment, and impaired melanocyte migration can all contribute to the vitiligo  initiation process. Autoimmune mechanisms are  likely to underlie generalized vitiligo, while a  more localized phenomenon (i.e. the altered  activities of sensitive nerves in the skin) may be  responsible for segmental or focal vitiligo. A site  of a skin physical trauma may develop vitiligo; it is  called a“ Koebner phenomenon”.