Definition

Polymyalgia rheumatica (PMR) is an inflammatory disorder. It results in muscle pain and stiffness in the body. The effects are most common in the shoulders, arms, hips, and thighs. About 15% of people with PMR will also develop giant cell arteritis]]> (GCA). GCA results in inflammation and swelling of arteries. This occurs most often in the head. If not treated quickly, GCA may cause permanent blindness.

Giant Cell Arteritis

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Causes

The exact cause is not known. Inflammatory conditions tend to be due to some kind of problem with the immune system. Some evidence suggests that certain viruses could be responsible for PMR and GCA. Genetic factors may also play a role as well.

Risk Factors

Factors that may increase the risk for PMR and GCA include:

• Age: 50 and older
• Sex: female
• Ethnicity: PMR is most common in Caucasians, particularly those from northern Europe

Symptoms

Symptoms of PMR often develop within two weeks. They may include:

• Muscle pain and/or stiffness in the hip, shoulder, or neck areas
• Stiffness in the morning
• Fever
• Unexplained weight loss
• Anemia]]>
• Fatigue
• Mood changes

Symptoms of GCA may include:

• All PMR symptoms
• Headache, sometimes very severe, may also be associated with scalp hypersensitivity to touch
• Pain or tenderness in the temple
• Changes in vision
• Pain in the jaw or tongue with chewing

GCA needs to be treated immediately. This condition can lead to permanent blindness.

Diagnosis

Your doctor will ask about your symptoms and medical history. A physical exam will be done. There is no single test for PMR. To support the diagnosis and rule out other conditions, tests may include:

• Erythrocyte sedimentation rate (ESR)—a blood test that measures how quickly red blood cells fall to the bottom of a test tube. In the case of inflammation, levels of fibrinogen increase in the blood. Fibrinogen makes the red blood cells clump. This makes them fall faster.
• Rheumatoid factor (RF)—a blood test that looks for a specific antibody (RF) in the blood. A positive RF test suggests a condition other than PMR.
• Complete blood count—a blood test that measures the amount of different blood cells present in whole blood. Patients with GCA or PMR often have anemia. This will result in low counts of red blood cells. Patients with PMR have elevated levels of platelets.
• C-reactive protein—a protein produced in the liver. It increases when there is inflammation.
• Muscle biopsy]]> —removal of a sample of muscle tissue for examination (rare).

If you have PMR, your doctor may also consider the possibility of GCA. Evaluation for GCA includes:

• Physical exam, including vision test
• ]]>Biopsy]]> of an affected blood vessel is necessary to confirm the diagnosis

Treatment

Prevention

There are no known steps to prevent either PMR or GCA.