Reiter's syndrome is a rare type of arthritis that causes inflammation of the urinary tract, eyes, skin, mucus membranes, and joints. Reiter's syndrome, also called reactive arthritis, is believed to occur as a reaction to certain infections of the reproductive system and the digestive system. Infections that can lead to the complication of Reiter's syndrome include a common sexually transmitted disease called chlamydia. This is the most common cause of Reiter's syndrome. A less common cause of Reiter's syndrome is food poisoning due to Salmonella, Shigella, Yersinia or Campylobacter infection. Why some people develop Reiter's syndrome in reaction to these infections and other people don't is not known, but having a certain genetic factor called HLA-B27 increases a person's chance of developing Reiter's syndrome.