Definition:

Polymyalgia rheumatica (PMR) is a relatively common inflammatory rheumatic disease in people older than 50 years of age. PMR is a clinical condition defined as the presence of inflammatory pain in the limb girdles. Range of motion is decreased at the shoulder and pelvic girdles, and the neck and hip girdle may also be involved. These symptoms often persist for at least 1 month and are combined with incapacitating morning stiffness, a decline in general health, and an elevated acute-phase response. Onset of PMR symptoms may be acute or gradual. It is known that PMR patients share many pathogenetic features with giant cell arteritis (GCA). Despite the similarities in age of onset and some of the clinical manifestations, the relationship between GCA and PMR is not yet clearly established. One-third of PMR patients have systemic manifestations such as low-grade fever, malaise, and anorexia, but these are often milder than systemic symptoms in GCA patients. PMR is a benign and highly steroid-sensitive disease that should resolve fully with low-dose glucocorticoid therapy for 12-24 months, although one or two relapses may occur. The diagnosis of PMR is made primarily on clinical grounds and is bolstered by laboratory evidence of an acute-phase reaction. There is no single diagnostic test for PMR, but sets of diagnostic and classification criteria have been suggested by several groups of investigators.