@kayept, I agree with you.
PMR and GCA afflict Europeans, especially Northern Europeans, and Caucasians at a higher rate than people of other races. I read that Minnesota has the highest incidence of PMR/GCA in the US.
GCA was identified as far back as the 10th Century by a physician in Baghdad who observed swollen arteries concurrent with vision loss.
My maternal aunt had both PMR/GCA, and I got both about 5 years ago. Both of us experienced the onset of symptoms after physical injuries. My aunt hurt her back moving furniture and I hurt my ankle walking backwards. Ironically, my mother-in-law came down with it after a family reunion that involved a road trip from Ontario to Florida, probably very stressful for her. She was in her 80s at the time and had a tough time getting it diagnosed. A doctor she was referred to and some family members thought she was malingering.
I think there's a trigger which causes the immune system of a person predisposed to go into overdrive. I often think PMR/GCA was waiting in the wings to get me.