Most people with reactive arthritis recover fully from the initial flare of symptoms and are able to return to regular activities 2 to 6 months after the first symptoms appear. In such cases, the symptoms of arthritis may last up to 12 months, although these are usually very mild and do not interfere with daily activities. Approximately 20 percent of people with reactive arthritis will have chronic (long-term) arthritis, which usually is mild.

Studies show that between 15 and 50 percent of patients will develop symptoms again sometime after the initial flare has disappeared. It is possible that such relapses may be due to reinfection. Back pain and arthritis are the symptoms that most commonly reappear. A small percentage of patients will have chronic, severe arthritis that is difficult to control with treatment and may cause joint deformity.

Researchers Learning About Reactive Arthritis

Researchers continue to investigate the causes of reactive arthritis and study treatments for the condition. For example:

• Researchers are trying to better understand the relationship between infection and reactive arthritis. In particular, they are trying to determine why an infection triggers arthritis and why some people who develop infections get reactive arthritis while others do not. Scientists also are studying why people with the genetic factor HLA-B27 are more at risk than others.

• Researchers are developing methods to detect the location of the triggering bacteria in the body. Some scientists suspect that after the bacteria enter the body, they are transported to the joints, where they can remain in small amounts indefinitely.

• Researchers are testing combination treatments for reactive arthritis. In particular, they are testing the use of antibiotics in combination with TNF inhibitors and with other immunosuppressant medicines, such as methotrexate and sulfasalazine.