Abstract
Polymyalgia rheumatica and elderly-onset rheumatoid arthritis often occur due to similar symptoms, and differentiation thereof is very difficult, especially in negative cases of anti-cyclic citrullinated peptide antibodies. Provisional classification criteria for polymyalgia rheumatica was reported from ACR /EULAR in 2012, but differentiation remains difficult. In such cases, the presence and distribution of peripheral arthritis are reported as a useful differentiation point in general clinical practice without special imaging. As a process of differential diagnosis, elderly-onset rheumatoid arthritis is given priority for its erosive joint destruction. Diagnosis of polymyalgia rheumatica is next. After the start of therapy for polymyalgia rheumatica, it is important to reconsider the diagnosis regularly, with attention whether its clinical picture changes because some cases may develop from polymyalgia rheumatica to rheumatoid arthritis later.
