Polymyalgia Rheumatica (PMR) is a clinical syndrome that can be a manifestation of many pathological processes, including rheumatoid arthritis, cancer, and including giant cell arteritis (GCA). PMR usually affects persons older than 50 years, and women are affected twice as often as men. The disorder may have either an acute or insidious onset, producing pain and stiffness in the proximal musculature. Fatigue, depression, weight loss, and fever may also occur. In all likelihood, PMR is a disease of medium-sized and large arteries that is seen in many different entities, GCA and rheumatoid arthritis. The prevalence of PMR may equal that of rheumatoid arthritis in individuals older than 50 years. The two disorders often overlap in clinical presentation, and classification may sometimes present a problem. Symptoms and signs are nonspecific. The differential diagnosis includes rheumatoid arthritis, polymyositis, occult malignant disease, infectious disease, myofascial pain syndromes, and functional abnormalities. In one study, the ESR was strikingly elevated in 99% of patients, hemoglobin levels were decreased in 47%, a2-globulin levels were abnormal in 33%, aspartate aminotransferase levels were elevated in 23%, and alkaline phosphatase levels were increased in 10%. An increased fibrinogen level and normal creatine kinase and aldolase levels are also common.

A dramatic response to corticosteroids (in 24 to 48 hours) helps confirm the diagnosis of PMR, although this finding is not specific. Because PMR and GCA are often parts of the same disease spectrum, therapy must be directed at both symptomatic relief and prevention of catastrophic visual loss. An initial daily regimen of low-dose prednisone (6 to 10mg) or nonsteroidal agents may control morning stiffness and pain. In the absence of ocular symptoms, PMR can be treated with maximal doses of nonsteroidal anti-inflammatory drugs. Prednisone (10 to 15mg daily) will give a more prompt therapeutic response, but the toxicity from long-term use at dosages greater than 7.5 mg/day is high. Usually, low-dosage maintenance can be achieved within weeks. Reassessment is mandatory if ocular or other symptoms develop; in such cases, the steroid dosage must be increased. Some patients require a low dosage of steroids for life; others may be weaned from steroids after 2-4 years.