After reading some other posts on here, I should mention a chemical exposure I had about three weeks before symptoms started. It was to an outdoor cleaning solution for siding decks etc. Active ingredient on label was 5% sodium hypochlorite (household bleach). After using it I noticed my respiratory tract was very irritated and felt inflamed. No trouble breathing so I did not go to hospital. It hurt for about half a day. I checked MSDS later on and found out it also contained Tri Sodium Phosphate which was not on the label. It is an alkaline salt ph 13. Doctors dismissed this having anything to do with my symptoms because neithet ingredient condidered neurotoxins but it does seem very coincidental to me. Rheum did have me get a chest x ray as part of her examination and everything looked fine according to report.