Sorry you are having so much trouble! That doesn't sound fun. Why would an injection lead to a flare? My understanding was that the risk was rupture. But that risk seems to increase the longer it is inflamed as well (?). Or is that the prolotherapy?--need to look up what that is
My achilles is the same--still swollen, but only mildly painful (mostly when I first use it). It's been 18 months now *sigh*. Nothing I have tried so far has touched it (steroids, Voltaren gel, Embrel, Cosentyx)--or my mild axial symptoms, either. I am allergic to sulfa drugs so sulfasalazine is not an option for me. I will see my rheumy in December and decide what to try next. Or maybe I will take a break from throwing drugs at it with no effect.
Have you tried methotrexate? It seems to work best for peripheral inflammation. My son takes it for his peripheral spondylitis (knees, mainly) and it really helps him. Apologies if you've mentioned this and I didn't remember