When i had my onset, it was in hands for two days, then it was shoulders, hips, ankles and was excruciating, accompanied by profound weakness. I couldn't sleep because if I rolled over my shoulders screamed. I had to put my shampoo bottle between my knees to squeeze because my hands were too weak.
My new Rheumy a few weeks later was inclined toward PMR but something made her give me a trial of Humira - and i had improvement in less than a week.

The point is that our maladies are more similar than different. I still occasionally get a period of the shoulders/hips thing and my Rheumy gives me 20 mg of Prednisone to taper down. But what I live with every day is RA. So do I have both or just some weird variant? Who knows - or cares. But you are correct that treating RA with Remicade won't do anything for the PMR symptoms. That takes Prednisone.