Polymyalgia Rheumatica

Summary

Giant cell (temporal) arteritis was first described by Horton and colleagues in 1932, and polymyalgia rheumatica in 1957 by Barber who suggested this title for an entity resembling, but distinct from, rheumatoid arthritis of unknown aetiology in the elderly. Arteritic features were sufficiently common in polymyalgia rheumatica to suggest an arteriopathy as a cause, further evidence of this being the change from the clinical picture of polymyalgia rheumatica to giant cell arteritis and vice versa in many patients such that the alternative title polymyalgia arteritica was suggested. The clinical picture of polymyalgia rheumatica is that of an elderly patient, more often female than male, usually over 60 years of age, with painful stiffness in the girdle joints and muscles of the shoulders and hips, but seldom with findings in peripheral or intermediate joints. The painful stiffness in the shoulders, hips and thighs is worse in the early morning. An erythrocyte sedimentation rate over 50mm in 1 hour is usual, and there is a rapid and dramatic response to small doses of corticosteroids (around 10mg prednisolone daily). Arteritic and axial arthritic features have been noted by different authors in different ratios, the disorder gradually abating naturally over periods varying from several months to 7 to 10 years. Deaths, when they occur in this elderly group of patients, have usually been unrelated to the disease or its treatment, but osteoporotic vertebral crush fractures are not uncommon. Partial or complete blindness may occur in patients with either giant cell arteritis or polymyalgia rheumatica, often appearing rapidly after cessation of corticosteroid therapy or rapid reduction of dosage.

While non-steroidal anti-inflammatory agents (NSAIDs) are sufficient treatment in mild cases presenting with no arterial features, corticosteroids in conservative doses (around 10mg prednisolone daily initially) are much more rapidly and completely effective. A higher dosage of 20 to 30mg daily is needed initially in those with an arteritic picture and where vision is threatened, 50mg daily or possibly more is needed.

Polymyalgia rheumatica was previously diagnosed infrequently and many elderly patients suffered unnecessarily. While this still occurs today, many patients are being treated for prolonged periods on corticosteroids where these drugs are probably unnecessary and simple analgesics or NSAIDs would suffice. In the absence of a diagnostic test other than arterial biopsy, diagnosis rests on clinical judgement and treatment is necessarily empirical.