Leukoderma. Reason. i'd be really!

Sir, My father came down with the leukoderma condition since about 8-10 years now and so far as we believe the source of this condition was consuming milk and fish simultaneously , then again we are just saying what others preach to us. My father has went to a dozen of doctors, couple of ayurvedic doctors and even in the direction of homeopathy which wasn't even in the least bit helpful. My father developed anxiety due to this since the social norms in India provide but a little place to people who are going through this condition. He also has sensitive stomach and hence develop gastronomical issues in a moment as a result, many medicines had to be ditched because of that reason. I'd be really thankful to you if you could list down possible methods of recovering from leukoderma condition with least possible gastronomical impacts.