Reiter's Syndrome
Reiter’s syndrome is a form of reactive arthritis. It is uncommon but can be a debilitating syndrome that follows a gastrointestinal or genitourinary infection. The most common gastrointestinal bacteria involved are Salmonella, Campylobacter, Yersinia, and Shigella. Reiter’s syndrome is characterized by a triad of arthritis, conjunctivitis, and urethritis, although not all three symptoms occur in all affected individuals (Hill Gaston & Lillicrap, 2003). The reactive arthritis associated with Reiter’s syndrome may develop after a person eats food that has been tainted with bacteria. Although the initial infection may not be recognized, reactive arthritis can still occur. Reactive arthritis typically involves inflammation of one joint (monoarthritis) or four or fewer joints (oligoarthritis), preferentially affecting those of the lower extremities. The pattern of joint involvement is usually asymmetric. Inflammation is common at an enthesis (a places where ligaments and tendons attach to bone), especially the knee and the ankle.
The term Reiter’s syndrome has fallen into disfavor. Reiter’s syndrome in recent medical literature is simply referred to as reactive arthritis which may or may not be accompanied by extraintestinal manifestations.
Salmonella has been the most frequently studied bacteria associated with reactive arthritis. Overall, studies have found rates of Salmonella-associated reactive arthritis to vary between 6 and 30% (Hill Gaston, & Lillicrap, 2003). The frequency of postinfectious Reiter’s syndrome, however, has not been well described. In a Washington State study of an outbreak of foodborne Salmonella gastroenteritis, while 29% developed arthritis, only 3% developed the triad of symptoms associated with Reiter’s syndrome (Dworkin, et al., 2001). However, the range for the occurrence of new joint pain after enteric infection is reported to be between 1 and 4% in adults with Campylobacter, Salmonella, or Shigella infections (Rees, et al., 2004). In addition, individuals of Caucasian descent may be more likely than those of Asian descent to develop reactive arthritis (McColl, et al., 2000), and children may be less susceptible than adults to reactive arthritis following infection with Salmonella (Rudwaleit, et al., 2001).
The frequency of acute reactive arthritis from other bacteria varies widely and the frequency of Reiter’s syndrome is not as well studied. Reactive arthritis has been reported to occur in between 0.6% and 24% of Campylobacter gastroenteritis patients (Pope, et al., 2007). After Shigella infections, subsequent reactive arthritis has ranged from 1.5% to 7% (Hannu, et al., 2005).
A clear association has been made between reactive arthritis and a genetic factor called the human leukocyte antigen (HLA) B27 genotype. HLA is the major histocompatibility complex in humans; these are proteins present on the surface of all body cells that contain a nucleus, and are in especially high concentrations in white blood cells (leukocytes). It is thought that HLA-B27 may affect the elimination of the infecting bacteria or an individual’s immune response (Hill Gaston, & Lillicrap, 2003). HLA-B27 has been shown to be a predisposing factor in one-half to over two-thirds of individuals with reactive arthritis ( Barth & Segal, 1999; Hill Gaston, & Lillicrap, 2003). While HLA-B27 does not appear to predispose to the initial infection itself, it increases the risk of developing arthritis that is more likely to be severe and prolonged. This risk may be slightly greater for Salmonella and Yersinia-associated arthritis than with Campylobacter, but more research is required to clarify this (Hill Gaston, & Lillicrap, 2003).
Why Have Some Forms of Reactive Arthritis Been Called Reiter’s Syndrome?
One could also ask, “Why isn’t Reiter’s syndrome called Reiter’s syndrome any more?” The answer is that the syndrome is named for Hans Reiter who described a soldier with the triad of urethritis, conjunctivitis, and arthritis after having bloody diarrhea in 1916. However, the history of this constellation of signs actually predates his description. And what is disturbing is that Reiter was a high-ranking Nazi official who was responsible for medical experiments in concentration camps (Panush, et al., 2003 and Petersel & Sigal, 2005). As a result, the term Reiter’s syndrome has fallen out of favor and reactive arthritis is preferred to describe the post-infectious arthritis that may be accompanied by extra-articular manifestations (such as urethritis and conjunctivitis).