May 25, 2012
Dear Mayo Clinic:
My mother was just diagnosed with polymyalgia rheumatica. What is it, and what causes the condition? Is the treatment safe?
Polymyalgia rheumatica is a treatable inflammatory disorder that causes muscle and joint pain and stiffness. Proper treatment can often improve the symptoms in a matter of days or even overnight. Keeping the disorder in check as it subsides usually involves careful medication management.
Inflammation is the body's usual response to injury or disease. But in some disorders — known collectively as rheumatic diseases — inflammatory activity erupts where there's no apparent need for the response. Such is the case with polymyalgia rheumatica.
Although the cause of the condition isn't well understood, the pain and stiffness of the disorder result from the activity of inflammatory cells and proteins that are a normal part of your body's disease-fighting immune system. The aberrant inflammatory activity is generally concentrated in tissues surrounding the affected muscles and joints, resulting in signs and symptoms that begin which can include:
When pain and stiffness first appear, it's also common to run a low-grade fever, experience fatigue, be anemic and generally feel unwell. Loss of appetite, unintended weight loss and depression may also occur early on in the disorder.
Most people who develop polymyalgia rheumatica are older than 65 — rarely does it affect people younger than 50. The disorder is more common in women.
Research suggests that a combination of inherited and environmental factors may contribute to the development of polymyalgia rheumatica. It's most common in people of Northern European heritage — in particular, those of Scandinavian descent — and may run in families. Patterns where new cases of polymyalgia rheumatica appear in cycles suggest there may be some connection with contagious viral diseases.
Certain blood tests can be helpful in making a diagnosis and beginning a treatment plan. An erythrocyte sedimentation rate (ESR) — commonly referred to as a sed rate — reflects changes in red blood cells (erythrocytes) related to inflammation. An elevated sed rate indicates the inflammatory response of the immune system is heightened. Another blood test measures the concentration of C-reactive protein (CRP), which increases when there's inflammatory activity.
The primary treatment for polymyalgia rheumatica is a low dose of an oral corticosteroid, such as prednisone. This usually produces relief from pain and stiffness within the first two or three days. If it does not, the dose may need to be increased. The corticosteroid dose is gradually decreased based on improvement in symptoms and follow-up blood test results. However, if symptoms of polymyalgia rheumatica return, it may be necessary to temporarily increase the corticosteroid dose.
The goal in managing treatment of polymyalgia rheumatica is to keep the corticosteroid dose as low as possible. Most people with the disorder need to continue corticosteroid treatment for one to two years, and sometimes longer.
Because long-term use of these drugs can result in a number of serious side effects, frequent follow-up visits with a doctor are recommended. He or she can monitor treatment effects, watch for potential problems, and adjust the corticosteroid dosage.
Among possible side effects related to corticosteroid treatment are a loss of bone density and weakening of bones (osteoporosis). To help reduce the risk of bone fractures, calcium and vitamin D supplements may be prescribed.
Other side effects of long-term corticosteroid use that may require treatment include high blood pressure, which increases the risk of cardiovascular and kidney disease; diabetes, which can cause tissue damage in a number of body systems; cataracts, which can significantly impair your vision; and depression or other emotional disturbances
With proper diagnosis and treatment, the life expectancy of someone treated for polymyalgia rheumatica is generally the same as for anyone else of the same age. New medications that target specific components of the immune system are being studied as possible treatment options for the disorder.
— Kenneth J. Warrington, M.D., Rheumatology, Mayo Clinic, Rochester, Minn.