What Are Polymyalgia Rheumatica and Giant Cell Arteritis?

Polymyalgia rheumatica is a rheumatic disorder that is associated with moderate to severe muscle pain and stiffness in the neck, shoulder, and hip area. Stiffness is most noticeable in the morning. This disorder may develop rapidly--in some patients, overnight. In other people, polymyalgia rheumatica develops more gradually. The cause of polymyalgia rheumatica is not known; however, possibilities include immune system abnormalities and genetic factors. The fact that polymyalgia rheumatica is rare in people under the age of 50 suggests it may be linked to the aging process.

Polymyalgia rheumatica may go away without treatment in 1 to several years. With treatment, the symptoms of polymyalgia rheumatica are quickly controlled, but relapse if treatment is stopped too early.

Giant cell arteritis, also known as temporal arteritis and cranial arteritis, is a disorder that results in swelling of arteries in the head (most often the temporal arteries, which are located on the temples on each side of the head), neck, and arms. This swelling causes the arteries to narrow, reducing blood flow. Early treatment is critical for good prognosis.

How Are Polymyalgia Rheumatica and Giant Cell Arteritis Related?

It is unclear how or why polymyalgia rheumatica and giant cell arteritis are related, but an estimated 15 percent of people in the United States with polymyalgia rheumatica also develop giant cell arteritis. Patients can develop giant cell arteritis either at the same time as polymyalgia rheumatica or after the polymyalgia symptoms disappear. About half of the people affected by giant cell arteritis also have polymyalgia rheumatica.

When a person is diagnosed with polymyalgia rheumatica, the doctor also should look for symptoms of giant cell arteritis because of the risk of blindness. With proper treatment, the disease is not threatening. Untreated, however, giant cell arteritis can lead to serious complications including permanent vision loss and stroke. Patients must learn to recognize the signs of giant cell arteritis, because they can develop even after the symptoms of polymyalgia rheumatica disappear. Patients should report any symptoms to the doctor immediately.

Who Is at Risk?

White women over the age of 50 are most at risk of developing polymyalgia rheumatica and giant cell arteritis. Women are twice as likely as men to develop the conditions. Both conditions almost exclusively affect people over the age of 50. The average age at onset is 70 years. Polymyalgia rheumatica and giant cell arteritis are quite common. In the United States, it is estimated that 700 per 100,000 people in the general population over 50 years of age develop polymyalgia rheumatica. An estimated 200 per 100,000 people over the age of 50 develop giant cell arteritis.