How lupus differs from arthritis
Lupus is not a form of arthritis, but it does include arthritis as one of the most common symptoms, so it is easy to see why some people think about it that way. It is very important not to make this mistake, because lupus is quite different than any other illness that causes arthritis. It should not be lumped in with these other causes of arthritis, because the causes and the treatments are very different.
General arthritis vs. lupus arthritis
Arthritis is caused by either inflammation or wear and tear of the body’s joints. It is characterized by pain, stiffness, swelling and redness and can limit movement such as in the shoulders or knees.
Lupus arthritis is caused by inflammation. After a long time of uncontrolled lupus, however, people can have damage in the joints which causes problems even when the lupus is not flaring.
Other forms of arthritis are caused by sports injuries, being overweight, or by inflammation that is different from the type of inflammation seen in lupus.
The inflammatory process
Lupus is an autoimmune disease in which the immune system is very active and has trouble moderating itself, leading to widespread inflammation in the bloodstream. This bloodstream then serves every organ in the body.
It is still a cruel mystery, and quite unpredictable, to determine from patient to patient which types of healthy tissue might become inflamed or when.
Arthritis is the most common symptom seen in lupus, but it would be an extremely rare patient with lupus who experienced arthritis as their only manifestation. Other common manifestations are rashes and inflammation of the blood vessels. In fact, almost any organ can become inflamed in some patients. Some patients only experience inflammation in the skin and joints, others in multiple areas.
In some cases, lupus manifests in only one part of the body, though the most common examples of that are rash and decreased blood cells.