It is classified as a rheumatic disease, although the etiology is undetermined. Muscle strength and electromyogram are normal. Some evidence suggests cell-mediated injury to the elastic lamina in the blood vessels in the affected muscle groups. Caucasians are affected more than other ethnic groups.
Patients complain of pain and stiffness in the proximal muscle groups that is worse in the morning.
The signs and symptoms of PMR are nonspecific, and objective findings on physical examination often are lacking. The goal of therapy is to suppress autoimmune activity. They modify the body's immune response to diverse stimuli. By reversing increased capillary permeability and suppressing PMN activity, it may decrease inflammation. PMR is rapidly responsive to low doses of prednisone.