I think infections caused flares of something although I don't think the flares were always a PMR flare. I was diagnosed with "reactive arthritis" which derives its name from a reaction to an infection.

Prednisone would relieve these painful flares of reactive arthritis but I often received antibiotics in addition to prednisone. Antibiotics alone were never enough to stop the systemic inflammation. I also needed moderately high doses of prednisone and that would relieve the pain quickly. I tapered off prednisone in a one or two months after each flare of reactive arthritis.

I still have reactive arthritis. It isn't likely to ever "go away" or "burn out" like PMR is said to do. Reactive arthritis usually occurs at a younger age and I was diagnosed at the age of 32.

Twenty years later, at the age of 52, something different happened. My rheumatologist was confused by my symptoms which were entirely different than anything I had experienced before. I was diagnosed with PMR on top of reactive arthritis. I still needed 40 mg of prednisone to control the pain but I never could taper off prednisone for 12 years after that.

I had more frequent flares along with chronically elevated inflammation markers. The flares never did go into remission in spite of moderately high doses of prednisone. My rheumatologist thought prednisone and other immunosuppressive medications were putting me at risk for infections. Recurring infections aren't a good thing when you have reactive arthritis.

My rheumatologist said my primary diagnosis PMR which never did burn itself out until a biologic was tried. A biologic allowed me to taper off prednisone and now I don't have so many infections. As long as I don't have infections then reactive arthritis stays quiet.