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Harvard Medical School

Reiter's Syndrome

What Is It?

Reiter’s syndrome is a rare disease that causes a form of arthritis, along with inflammation of the urinary tract and eyes. It is triggered by an infection, usually by a sexually transmitted organism or by certain gastrointestinal bacteria.

The most common infection causing Reiter’s syndrome is the sexually transmitted disease Chlamydia. Reiter’s syndrome can also be caused by gastrointestinal infection from bacteria such as salmonella, shigella, campylobacter, or Yersinia, which can cause diarrhea and vomiting. These bacteria often are found in contaminated food or water. These infections are common, but Reiter’s syndrome is not. Scientists believe that people who develop Reiter's syndrome have a certain genetic makeup. In some studies, approximately 70% of people with Reiter’s syndrome have a gene called HLA-B27, compared with 8% of the general population.

Reiter’s syndrome is thought to be an autoimmune disorder, which means the body’s immune system mistakenly attacks its own tissues. In this case, the immune system is jolted into action by the infection, but continues attacking after the infection is gone.

Reiter’s Syndrome typically includes arthritis, eye inflammation (conjunctivitis or uveitis) and inflammation of the urethra (urethritis). However, some people develop only one or two of these. The arthritis without eye or urinary inflammation is often called reactive arthritis.

Reiter's syndrome is most common in people between the ages of 20 and 40. About 3 in 100,000 men under age 50 develop the disease.