Polymyalgia rheumatica

Polymyalgia rheumatica

Polymyalgia rheumatica is an inflammatory disorder that causes muscle and joints pain and stiffness. The pain usually starts in the shoulders and afterwards it may also begin in the upper arm and very rarely in the upper leg. This disorder affects both sides of the body, and involves also arms, legs, neck, and buttock areas. The pains begin quickly and are worse in the morning. Patients present more pain when they move that body part. People with the disease are typically over 50 years of age but it affects mostly people over 70 years old. It is very rare to find patients younger than 50 years old presenting this condition. Polymyalgia rheumatica is abbreviated PMR.

The exact cause of polymyalgia rheumatica is unknown. Two factors appear to be involved in the development of this condition:

  • Genetics. Certain genes and gene variations may increase the susceptibility to get this illness

  • An environmental exposure. New cases of polymyalgia rheumatica tend to come iteratively (in cycles) and may develop seasonally. This gives a hint that an environmental trigger, such as a virus, might play a role. But no specific virus has been shown to cause polymyalgia rheumatica.

Rarely, the disease is associated with a cancer. In this setting, the cancer may be initiating an inflammatory immune response to cause the polymyalgia rheumatica symptoms

Polymyalgia rheumatica is related to another inflammatory disorder called giant cell arteritis, which can cause headaches, vision difficulties, jaw pain and scalp tenderness. It's possible to have both of these conditions together. Giant cell arteritis has as a consequence an inflammation in the lining of arteries, generally the arteries located in the temples. Giant cell arteritis must be treated immediately due to the fact that it can lead to stroke or blindness if left untreated.

Polymyalgia rheumatica and giant cell arteritis may actually be the same disease but with different manifestations. The overlap between the two diseases is significant:

  • About 20 percent of people with polymyalgia rheumatica also have signs and symptoms of giant cell arteritis.

  • About half of the people with giant cell arteritis may also have polymyalgia rheumatica.

Since both illnesses are very simmilar it is important to clearly separate them via special tests in order to be able to treat the given condition efficiently and effectively.

The risks factors for polymyalgia rheumatica include age, sex and race/geographical region. The average age at onset of the disease is 73 years old, women are twice more affected by this illness as men. Polymyalgia rheumatica is most common among whites in northern European populations but all races can get PMR.