Good question @girastancil, PMR is difficult to diagnose and there are other condtions that mimic PMR. Here are a few resources on the topic.

-- Polymyalgia rheumatica or Lyme disease? How to avoid misdiagnosis in older patients:
https://pubmed.ncbi.nlm.nih.gov/7816713/
-- Letters: Don’t Forget Lyme Disease When Considering Polymyalgia Rheumatica:
https://www.the-rheumatologist.org/article/letters-dont-forget-lyme-disease-when-considering-polymyalgia-rheumatica/
-- Diseases that mimic polymyalgia rheumatica (PMR): https://www.medicalnewstoday.com/articles/diseases-that-mimic-polymyalgia-rheumatica