Thanks for your response. To clarify, I haven’t experienced ReA- my then 25 yo son did following knee surgery. That was about 3 yrs before I had my extremely acute and intensive onset of seronegative RA in 2012. My Rheumatologist in NYC made that call.
I’ve had flares over the last dozen years but the pattern is that it begins distally in fingers and/or toes and marches up to elbow or knee then to shoulders and/or hips. Where it is disruptive to activity and sleep for a week to 10 days and then just subsides over 2-3 days.

I had a bad experience with steroids in the 80’s before back surgery for ruptured disc, so had always refused steroids until early November of this year when I asked for it in a particularly painful flare. Amazing stuff. Pain, mood, energy, mental acuity - I was pinging on all cylinders. 😁 I will have to restrain myself not to want it every time.

So the fact that my pain in flares always settles in large joints and my initial symptoms included large joints is why I say I’m an odd duck mix of RA and PMR. That may not be a thing.