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What Is Reactive Arthritis?

Feb 20, 2010; 2:52 PM ET

Reactive arthritis is a form of arthritis, or joint inflammation, that occurs as a "reaction" to an infection elsewhere in the body. Inflammation is a characteristic reaction of tissues to injury or disease and is marked by swelling, redness, heat, and pain. Besides this joint inflammation, reactive arthritis is associated with two other symptoms: redness and inflammation of the eyes (conjunctivitis) and inflammation of the urinary tract (urethritis). These symptoms may occur alone, together, or not at all. Reactive arthritis is also known as Reiter's syndrome, and your doctor may refer to it by yet another term, as a seronegative spondyloarthropathy. The seronegative spondyloarthropathies are a group of disorders that can cause inflammation throughout the body, especially in the spine. (Examples of other disorders in this group include psoriatic arthritis, ankylosing spondylitis, and the kind of arthritis that sometimes accompanies inflammatory bowel disease.)

One form of reactive arthritis is caused by an infection in the intestinal tract from eating food or handling substances that are contaminated with bacteria. This form of arthritis is sometimes called enteric or gastrointestinal reactive arthritis. The symptoms of reactive arthritis usually last 3 to 12 months, although symptoms can return or develop into a long-term disease in a small percentage of people.

What Causes Reactive Arthritis?

Reactive arthritis typically begins about 1 to 3 weeks after infection. Infections in the digestive tract that may trigger reactive arthritis include Salmonella, Shigella, Yersinia, and Campylobacter. People may become infected with these bacteria after eating or handling improperly prepared food, such as meats that are not stored at the proper temperature. Doctors do not know exactly why some people exposed to these bacteria develop reactive arthritis and others do not, but they have identified a genetic factor, human leukocyte antigen (HLA) B27, that increases a person's chance of developing reactive arthritis. Approximately 80 percent of people with reactive arthritis test positive for HLA-B27. However, inheriting the HLA-B27 gene does not necessarily mean you will get reactive arthritis. Eight percent of healthy people have the HLA-B27 gene, and only about one-fifth of them will develop reactive arthritis if they contract the triggering infections.

Is Reactive Arthritis Contagious?

Reactive arthritis is not contagious; that is, a person with the disorder cannot pass the arthritis on to someone else. However, the bacteria that can trigger reactive arthritis can be passed from person to person.

What Are the Symptoms of Reactive Arthritis?

Reactive arthritis most typically results in inflammation of the urogenital tract, the joints, and the eyes. Less common symptoms are mouth ulcers and skin rashes. Any of these symptoms may be so mild that patients do not notice them. They usually come and go over a period of several weeks to several months.

Joint Symptoms

The arthritis associated with reactive arthritis typically involves pain and swelling in the knees, ankles, and feet. Wrists, fingers, and other joints are affected less often. People with reactive arthritis commonly develop inflammation of the tendons (tendinitis) or at places where tendons attach to the bone (ethesitis). In many people with reactive arthritis, this results in heel pain or irritation of the Achilles tendon at the back of the ankle. Some people with reactive arthritis also develop heel spurs, which are bony growths in the heel that may cause chronic (long-lasting) foot pain. Approximately half of people with reactive arthritis report low-back and buttock pain.

Reactive arthritis also can cause spondylitis (inflammation of the vertebrae in the spinal column) or sacroiliitis (inflammation of the joints in the lower back that connect the spine to the pelvis). People with reactive arthritis who have the HLA-B27 gene are even more likely to develop spondylitis and/or sacroiliitis.

Eye Involvement

Conjunctivitis, an inflammation of the mucous membrane that covers the eyeball and eyelid, develops in approximately half of people with reactive arthritis. Some people may develop uveitis, which is an inflammation of the inner eye. Conjunctivitis and uveitis can cause redness of the eyes, eye pain and irritation, and blurred vision. Eye involvement typically occurs early in the course of reactive arthritis, and symptoms may come and go.

Other Symptoms

Between 20 and 40 percent of men with reactive arthritis develop small, shallow, painless sores (ulcers) on the end of the penis. A small percentage of men and women develop rashes or small, hard nodules on the soles of the feet and, less often, on the palms of their hands or elsewhere. In addition, some people with reactive arthritis develop mouth ulcers that come and go. In some cases, these ulcers are painless and go unnoticed.