When you think about arthritis, you likely think of joint disease. But there are certain types of arthritis that have extraarticular manifestations, which means the disease affects areas of the body outside of the joints. When this occurs, especially in multiple organ systems in the body, the type of arthritis is referred to as a systemic disease.
How Arthritis Can Affect the Rest of Your Body
Examples of extraarticular involvement include fever, fatigue, weakness, anemia, nodules, dry eyes and mouth, pulmonary fibrosis, pleural effusion (excessive amount of fluid in the lungs), vasculitis, nerve problems, gastrointestinal complications, skin complications, and kidney disease -- to name a few.
Types of arthritis that are classified as systemic disease include:
- Rheumatoid arthritis
- Lupus erythematosus
- Juvenile arthritis
- Psoriatic arthritis
- Sjogren's syndrome
Osteoarthritis is not considered a systemic disease because it affects only the joints and not other organ systems.
Is Rheumatoid Arthritis Always a Systemic Disease?
Not all rheumatoid arthritis patients develop complications outside of the joints. Patients are more likely to develop these types of complications if they are strongly positive for rheumatoid factor and they have had a slow onset of the disease. As you might expect, rheumatoid arthritis patients with systemic complications tend to do worse than those without such complications.
Why Does Rheumatoid Arthritis Affect Other Organ Systems?
Since we know some rheumatoid arthritis patients will develop only joint disease while others will develop systemic disease, you may be wondering why. That's a tough question -- akin to asking why a person gets rheumatoid arthritis at all.
According to rheumatologist Scott J. Zashin, M.D., there is likely a mix of genetics and environmental factors that contribute to why certain cases of rheumatoid arthritis are systemic. The risk of systemic disease is greatly increased when one has anti-CCP or rheumatoid factor antibodies -- the presence of which is influenced by environmental factors, like smoking, and a person's genetic makeup.
There are over 100 types of arthritis. Learning about the individual types of arthritis can help you determine whether systemic disease is likely, and what you can expect.
Primer on the Rheumatic Diseases. Arthritis Foundation. 13th Edition.
Interview with Raymond Federman MD. August 1998.