How Reactive Arthritis is Diagnosed

Reactive arthritis belongs to a group of medical conditions known as seronegative spondyloarthropathies. These are two words describe two characteristics of reactive arthritis. "Seronegative" implies that the form of arthritis won't test positive for an antibody called rheumatoid factor commonly found in rheumatoid arthritis. "Spondyloarthropathy" means that this form of arthritis may involve the back, ligamentous or tendon insertions into bone, or the hands and feet.

The presence or absence of rheumatoid factor is determined by testing the blood. The group of rheumatoid factor negative arthritic conditions includes:

-Ankylosing spondylitis

-Psoriatic arthritis

-Reactive arthritis

-Arthritis of inflammatory bowel disease

Once your physician has determined that your form of arthritis falls into the seronegative category, he or she will use specific clues from your history and symptomatic presentation to decide that you have reactive arthritis.

Reactive arthritis may also be called Reiter's syndrome. Clues to the diagnosis come directly from the medical history. Reactive arthritis often appears following an infection elsewhere in the body. Common infections include sexually transmitted disease (usually Chlamydia trachomatis) and diarrheal illness (when infected with Shigella, Salmonella, Yersinia, Campylobacter, or Clositridium difficile).

In fact, a common way medical students remember Reiter's syndrome is the saying "can't see, can't pee, can't climb a tree". This refers to Chlamydial infection of the conjunctiva of the eyes and urethral tract, and the resulting arthritis. Of course, in children it is much more common to develop reactive arthritis following a bout of infectious diarrhea.

Additional clues to the diagnosis of reactive arthritis come from the presenting symptoms. These symptoms include:

1. Arthritis involving only a few joints

2. Lower limb joints are involved more than upper extremity joints

3. Inflammation commonly noted at the insertion site of the Achilles tendon or plantar fascia along the bottom of the feet

4. Additional symptoms that don't involve joints such as

- painless ulcers in the mouth or on the penis

- a thick scaly rash on the soles or palms

- inflammation or infection of the urinary or genital systems

- constitutional symptoms (fever, weight loss, malaise)

The symptoms of reactive arthritis develop one to two weeks after sexual exposure, or within the timespan for the foodborne infection. The symptoms can, unfortunately, last for several months.

Treatment is focused on relieving the symptoms. Most cases will resolve within 6 months, although half of these individuals will have a recurrence of the next several years. Rarely, reactive arthritis can be a persistent condition.