I think trusting your own instincts is the best you can do. I don't think there is any exact way to know if anyone is having a PMR flare or not. I know there are many things that hurt just as much if not more than PMR. I also know prednisone will relieve symptoms of things that aren't PMR. That was my personal experience.

It is easier for me to say this now because I'm off prednisone and my pain is tolerable. I'm still being treated for PMR but not with prednisone. I'm now aware of medical problems I have that aren't PMR so I still have pain. When PMR was part of the equation, I didn't know about some of the other problems I have. There was also pain caused by my body trying to adjust to a low dose of Prednisone that wasn't PMR but still hurt.

When I had to cope with intolerable pain --- something needed to be done. The pain mostly happened in spite of my best attempts to taper slowly off prednisone. I could only tolerate so much pain. Lacking information to the contrary, I had to assume it was a PMR flare. Many times it was just my guess because I didn't call my rheumatologist every time that it happened. My rheumatologist could have evaluated me, ordered labs and other tests and it would have been better than my guess.

My main concern is about people on the internet who give medical advice and undermine the medical advice people receive from their doctors. People have said my rheumatologist is an idiot and I should take more Prednisone. I didn't need any help and support to take more Prednisone. Taking more Prednisone is the easy and popular thing to do. Tapering off Prednisone was much more difficult for me than increasing my dose.