What are some of the environmental causes for vitiligo?

Vitiligo: The exact cause of vitiligo is unknown. However, genetic and autoimmune factors are likely to be involved. Some patients have no family history of vitiligo or autoimmune disease but still develop the disease. Possible extrinsic factors include stress and certain industrial chemicals. I am not sure which chemicals specifically may be responsible. Cytomegalovirus may also play a role.