Retrospective analysis of the clinical course of patients treated for polymyalgia

Dung Do-Nguyen,¹ Charles A Inderjeeth,^1–3 Jack Edelman,² Patrick Cheah<sup>2

1</sup>Rehabilitation and Aged Care, North Metropolitan Health Service, ²Department of Rheumatology, Sir Charles Gairdner Hospital, ³Faculty of Medicine and Pharmacology, The University of Western Australia, Perth, WA, Australia

Background: Polymyalgia rheumatica is a chronic inflammatory rheumatic condition, for which the mainstay of treatment is corticosteroids. Here, we review the clinical course of treated patients initially presenting with polymyalgic symptoms.
Methods: A retrospective audit was performed of patients who presented with a possible diagnosis of polymyalgia rheumatica. Biochemical markers and prednisone doses were assessed at the initial review, at one month, and 3, 6, and 12 months later.
Results: A cohort of 135 patients was identified, comprising 91 females and 44 males of mean age 70.7 years. All patients were treated with oral prednisone at an initial mean dose of 21.3 mg. Mean baseline C-reactive protein level and erythrocyte sedimentation rate were 41.6 mg/L and 48.6 mm/hour, respectively. Following initiation of therapy, there was a dramatic and sustained decrease in both inflammatory markers. A clinical response was observed in 96.2% of patients, but remission was achieved in only 18.2%. Of those initially diagnosed with polymyalgia rheumatica, 24.8% were subsequently diagnosed with a different rheumatic condition.
Conclusion: The excellent response rate to corticosteroid therapy is well established in the literature, but in this research, remission rates were comparatively low during the 12-month study period. The current value of disease-modifying antirheumatic drugs and biologic therapy appears uncertain, and further trials to establish their precise role would be beneficial. A large portion of patients presenting with polymyalgia were eventually diagnosed to have another rheumatic disease, thus reflecting the broad differential diagnosis of polymyalgia symptoms. Polymyalgia symptoms can occur in patients with polymyalgia rheumatica and other rheumatic conditions. This group has a good response to prednisone therapy, although remission at 12 months appears to be uncommon. The gold standard of treatment remains corticosteroid therapy.

Keywords: polymyalgia rheumatica, diagnosis, treatment