Polymyalgia rheumatica, PMR, is almost exclusively a disease that affects those over 50, particularly Caucasian females. According to the Vasculitis Foundation, there is a sudden onset of symptoms, including fatigue, aching pain, muscle inflammation and morning stiffness, especially in the shoulders and hips. The fatigue and stiffness in the muscles around the joints can make it difficult to get dressed in the morning without assistance. There appears to be a link between PMR and giant cell arteritis, or GCA. The exact cause of PMR is unknown, but there are some theories.
Heredity
There may be a genetic component to developing polymyalgia rheumatica. According to MayoClinic.com, there may be a gene that has not yet been identified that is responsible for the expression of polymyalgia rheumatica. There seems to be a much higher incidence of polymyalgia rheumatica among those of Northern European descent. The results of most studies have been inconclusive, indicating there may be multiple causes of polymyalgia rheumatica. X-ray analyses of the bones in the involved joints appear normal. The goal of treatment is to reduce the pain and inflammation, and this is accomplished through the use of steroids, such as prednisone.
Infection
While polymyalgia rheumatica is not an infection itself, the symptoms may actually be triggered by an infection, possibly a virus. According to MayoClinic.com, the often sudden onset of debilitating muscular pain, inflammation, malaise and fever suggest the presence or interference of an infection. New cases sometimes appear in cycles, which also suggest an infectious agent is contributing to the disease process. Several common viruses are being studied as possible causative factors in the development of polymyalgia rheumatica.
Abnormal Immune Response
According to the National Institute of Arthritis and Musculoskeletal and Skin Diseases, polymyalgia rheumatica is considered to be a rheumatic disease. The inflammation appears to be associated with some type of immune disorder. Pain and inflammation are centered in the muscles around certain joints, not within the joints themselves. The symptoms typically affect both sides of the body. Although it is not understood why, there appears to be a link between polymyalgia rheumatica and giant cell arteritis. Giant cell arteritis, an inflammation of the lining of the temporal artery, frequently occurs at the same time as polymyalgia rheumatica or immediately following the resolution of its musculoskeletal symptoms. The symptoms of GCA include headache, temple tenderness and blurry vision or vision loss. Anyone who develops symptoms of polymyalgia rheumatica should also be evaluated for giant cell arteritis, because GCA can lead to permanent vision loss and stroke if undetected.
