I believe, but I have no scientific evidence to back this up, that my rheumatoid arthritis has become less since I have mostly given up dairy. I also noticed a very much stronger correlation with excessive dairy and pompholyx. I used to suffer badly from pompholyx, and now I just don't. It was like flicking a switch. I'm convinced it's dairy that causes that. I said this to a woman on the Slimming World group I joined a few years ago, who also suffered badly from pompholyx (my diagnosis based on the symptoms she described) and she'd never heard of the condition. She gave up dairy and within a month she told me hers had disappeared as well.
I'm a member of the National Rheumatoid Arthritis Society. They have occasional meetings. I once cycled to one, about 5 miles away. I felt very guilty, like a fraud. There were people who were much worse off than I am, including one woman, at least 10 years younger than I am, whose diagnosis was only about a year previously, and she was already confined to a wheelchair. How can I swan in there, looking as though there's nothing wrong with me (I still get occasional symptoms, but nothing like as bad as they were when this first manifested itself) and tell then all that they would all be OK if they just gave up $food? I only went once.
Pompholyx is a form of eczema that results in large, massively itchy blisters on the palms of the hands and soles of the feet. I used to drive a needle into them to remove the fluid. Then they would dry up and the blister would form a scale and drop off. Lovely condition.