Occurrence of polymyalgia rheumatica in rheumatoid arthritis.

Polymyalgia rheumatica and rheumatoid arthritis may be difficult to differentiate in elderly patients. Polymyalgic symptoms are common in the prodromal phase of rheumatoid arthritis and, as specific diagnostic tests do not exist for either condition, criteria for diagnosis of the diseases are based largely on clinical features. I2 The presence ofsynovitis similar to rheumatoid arthritis in some patients with polymyalgia rheumatica causes further problems.3 It is generally thought, however, that polymyalgia rheumatica does not occur in patients with rheumatoid arthritis; indeed, a diagnosis of rheumatoid arthritis has been used as a criterion for excluding polymyalgia rheumatica.34 We report the occurrence of polymyalgia rheumatica in patients who already had rheumatoid arthritis.