(December 2010) by Dr Kate Baddock
Polymyalgia rheumatica. Words many of you will have heard – not to be confused with fibromyalgia, which is not the same at all. Polymyalgia rheumatica or PMR as it is commonly known, is a condition which affects the two “girdles” – the shoulder girdle, which includes the shoulders and upper arms; and the pelvic girdle, which includes the hips and thighs.
The condition causes progressive aching and early morning stiffness and can go unrecognized and undiagnosed, sometimes for months. This is because the symptoms are very similar to ordinary arthritis, especially in the early phase, and are often mistaken for it. Some differences are that this condition is also associated with fatigue, a general feeling of unwellness, and even a slight fever.
During PMR, there is an inflammation of the blood vessels that line the involved joints of the shoulder and/or pelvic girdle, and there is some evidence to suggest that it may be caused by a number of different viruses, along with a genetic predisposition. It generally affects people older than 50 and women are twice as likely to get it as men.
A very important association is temporal arteritis, where the temporal artery (over your temple) becomes inflamed as part of the condition. This is characterized by severe localized headache and changes in vision. This is very significant and needs to be treated more aggressively.
PMR is diagnosed partly by the clinical picture, and partly by excluding other conditions. Tests for arthritis are negative, and often the only tests that are abnormal are the ESR (erythrocyte sedimentation rate) and CRP (complement reactive protein). These are both tests that measure inflammation and are very sensitive, but are not specific to PMR.
The treatment is prednisone orally, and treatment generally is for at least a year. As the inflammation gradually settles, the CRP (and ESR) returns to normal, and regular checking of the blood tests can be matched with slow reduction of the prednisone. It is not uncommon for there to be “flares” during that time with temporary increases in prednisone needed. Regular exercise is also helpful.