Polymyalgia rheumatica

Abstract

The epidemiology, relationship to giant cell arteritis (GCA), pathogenesis, pathology, clinical and laboratory features, differential diagnosis, and treatment of polymyalgia rheumatica (PMR) are reviewed. Patients with PMR are usually over 50 years of age, white, and female. There is an association between GCA and PMR that has important implications because of the risk of blindness and other severe vascular complications in patients with GCA. The causes of PMR and GCA are unknown, although the immune system is implicated in the pathogenesis of these diseases. PMR is characterized by muscle pain and stiffness in the shoulders and hips. The principal laboratory finding is an elevated erythrocyte sedimentation rate. The differential diagnosis of PMR includes a number of diseases that cause symmetrical arthritis. It may be particularly difficult to distinguish between PMR and GCA because patients with GCA usually have symptoms associated with PMR. Nonsteroidal anti-inflammatory agents may be effective in mild cases of PMR. However, corticosteroids, usually prednisone or prednisolone, are the class of drugs most widely used to treat PMR. They are effective in relieving the pain and reversing the abnormal laboratory values in most patients; responses can be apparent in 24-48 hours. Steroid-sparing agents such as methotrexate, dapsone, and azathioprine have no established role at present. Patients taking corticosteroids for PMR should be monitored for the occurrence of GCA and development of adverse effects associated with drug therapy. Corticosteroids are effective in treating PMR. Although patients with PMR must be monitored for the development of GCA, the prognosis for these patients is excellent.