Common Characteristics of Rheumatoid Arthritis
Rheumatoid arthritis is a systemic disease characterized by painful, swollen, inflamed joints.
It can occur at any time from infancy on, affecting not only particular joints and muscles, but
in extreme cases, vital organs as well. It most commonly occurs between the ages of 20 and 35,
with women three times as vulnerable as men until the age of 50, when the difference narrows.
Of the 6.5 million Americans affected, about one-third are free of symptoms for long periods
of time; of the children with juvenile rheumatoid arthritis, two-thirds recover completely by
adulthood.
No one knows exactly why rheumatoid arthritis occurs or how to prevent it. However, the disease
is most likely to occur in genetically susceptible people when some factor disturbs their immune
system. An increasing number of researchers believe that this factor may be a virus, with particular
emphasis focused on the Epstein-Barr virus, a herpes-like organism that is commonly associated
with infectious mononucleosis. Thus, while osteoarthritis is a wear-and-tear disease essentially
restricted to the weight-bearing joints, rheumatoid arthritis is best described as an autoimmune
disease, which means the body attacks its own tissues. The result is not only stiffness and pain
in specific areas, but general malaise and fatigue as well as fever and weight loss.
Classic Rheumatoid Arthritis
While there may be differences of opinion about what triggers the onset of rheumatoid arthritis
(some specialists think it begins as part of another severe illness; some associate it with unusual
emotional stress; still others point to infectious agents), there is general agreement about what
happens once the autoimmune system goes awry.
Joints are normally lubricated by a secretion from the membrane that forms their lining. This lining
is called the synovial membrane. In rheumatoid arthritis, synovial tissue becomes inflamed, leading
to an abnormally rapid proliferation of the synovial cells, crowding their way into the joint itself.
The inflamed synovial tissue eventually eats into the cartilage and may even begin to erode the bone.
