Wishing you luck... I don't know if GCA could pop up again as a problem, but I don't think so? My dad was deemed negative for GCA, and his rheumatologist never mentioned him needing to be screened again. I assume/hope she'd check it if he had symptoms of it.

But on the prednisone dose, if this helps, if tapering by 5 milligrams feels like it might be too, you could go more slowly.

My dad (I am his caregiver; he is the one with PMR) had at least 3 significant flares (ESR went from around 20 to near 100 each time) in the 3 tries to drop his dose by 5 milligrams. He was never diagnosed with GCA; his highest prednisone dose was 30 mg.

After the third flare, his rheumatologist suggested to try tapering more slowly--he's gone down by 2.5 mg. every two weeks, guided by his lab results (ESR and CRP) and symptoms. Depending on how annoying it was to cut the pills, we would either alternate doses (i.e. alternate 30 mg with 25 mg every other day), or cut them down to 27.5, and so on.

With that strategy, he only had one flare that came after he got down to 10 mg. Thankfully, it seemed to resolve on its own after a week, and he continued on 10 mg for another 2 weeks. And now we will go even slower, now that the dose is low.

His rheumatologist is suggesting alternating 10 mg and 7.5 mg. If all goes well, we'll go to 7.5 mg daily. My dad is really sensitive to medication; thankfully she understands this.