Vitiligo

Nature

Vitiligo () is a chronic autoimmune disorder that causes patches of skin to lose pigment or color. The cause of vitiligo is unknown, but it may be related to immune system changes, genetic factors, stress, or sun exposure. Treatment options include topical medications, light therapy, surgery and cosmetics.

Source: Wikipedia

Aggravates 
Aggravated by 
Type 
(G) Very specific problems