The problem with not treating the inflammation is developing Giant Cell Arteritis. (GCA). That can cause priblens including blindness. Yes, prednisone is a strong drug and some experience side effects, mine after six weeks are minimal but I no longer have any PMR pain.
I hope you look into this a bit more. And best of luck to you.
GCA:
https://www.mayoclinic.org/diseases-conditions/giant-cell-arteritis/symptoms-causes/syc-20372758