- reactive arthritis, defined as a joint inflammatory process in which the infection is known, originating either in the urinary or digestive tract, but where bacterial product is not detected in the joint
- reactive arthritis is classified within the group of spondyloarthritis, including ankylosing spondylitis, psoriatic arthritis, arthritis associated with inflammatory bowel disease, acute anterior uveitis, juvenile spondylitis, sacroiliitis and undifferentiated spondyloarthritis. The overall prevalence of this group of diseases is between 2% and 3%, which is at least 3 times more frequent than the prevalence of RA
- Reiter's disease is an example of a reaction arthritis
- way of classifying reactive arthritis according to the presence or absence of HLA-B27 (1)
- infectious arthritis or septic arthritis, was defined by the presence of infection somewhere in the body and identification of the infectious agent or microbial product in the joint
- post infectious arthritis, characterized by the presence of infection and identification of bacterial antigens in the joint, for example arthritis secondary to meningococcemia
Epidemiology of reactive arthritis
- difficult to determine because of the lack of diagnostic criteria, because of the difficulty in identifying, recognizing and treating the causative organisms, which can alter the subsequent course of the disease, the genetic variability of HLA-B27 and the presence of local environmental factors that also play a role, such as Yersinia enterocolitica infection, which is more common in certain geographic areas than in others
- prevalence is about 0.1% in the general population, with an annual incidence of 10 cases per 100,000 inhabitants (2)
- represents a rather low estimate because there is no clear clinical difference, especially in the early stages, between subgroups of spondyloarthritis, since a large proportion of patients are asymptomatic, approximately 36% and 26% in Chlamydia enteral infection
- any infectious microorganism can result in reactive arthritis, but those more commonly involved are Chlamydia trachomatis (C. trachomatis), Yersinia, Salmonella, Campylobacter and Streptococcus
- reactive arthritis is a systemic disease that affects young people between the second and fourth decades of life. It can affect children and older individuals
- usually occurs 2-4 weeks after a genitourinary (male: female, 9:1) or enteric (male: female, 1:1) infection
Clinical features associated with genitourinary infections are virtually identical to those associated with enteric infections. Clinically, there are 4 syndromes (2,4)
- 1 enthesopathic Syndrome.
- 2 peripheral arthritis: acute or subacute asymmetric oligoarticular arthritis, which affects the lower limbs.
- 3 axial and pelvic syndrome: spinal involvement with sacroiliitis.
- 4 extramusculoskeletal Syndrome
Investigations
- laboratory results are completely nonspecific. The ESR and CRP are elevated in at least 50% of patients
- presence of HLA-B27 is found in about 60% of patients and in a lower percentage in non- Caucasian populations. P-ANCA positivity is detected in 20%-30% of patients, but this finding is not specific
- both synovial fluid and synovial membrane biopsies, as well as imaging, do not contribute much to the diagnosis
- differential diagnosis includes other members of the spondyloarthritis, septic arthritis, Still's disease, Behcet disease and sarcoidosis group.
Management
- vast majority of affected patients with reactive arthritis respond to treatment with nonsteroidal antiinflammatory drugs (NSAIDs), but a significant proportion requires treatment with a second line of disease modifying agents
- biological agents, especiallyTNFblockers, have great impact on the treatment of refractory reactive arthritis patients (3)
- evidence showing that the combined use of antibiotics mayinduce complete remission and cure to Chlamydia induced reactive arthritis (4)
Prognosis:
- prognosis is variable
- most patients remain symptomatic, with joint pain, back pain, ankylosing spondylitis and development of long-term (15-20 years) disease (4)
- another group goes into permanent remission and a minority has a relapsing course
- certain risk factors for poor prognosis: nature of the infection, persistent infection with Chlamydia, the presence of HLA-B27 (axial involvement, ocular), male gender, recurrent arthritis and a family history of the disease
Reference:
- Dumond DC. Part II: principal evidence associating rheumatic diseases with microbial infection. In: Dumond DC, editor. Infection and immunology in the rheumatic diseases. London: Beadsworth; 1976. p. 95-6
- Colmegna I, Cuchacovich R, Espinoza LR. HLA-B27 associated reactive arthritis (ReA): pathogenic and clinical considerations. Clin Microbiol Rev. 2004;17:34863.
- Meyer A, Chatelus E, Wendling D, Berthelot JM, Dernis E, Houvenagel E, et al. Safety and efficacy of anti-tumor necrosis factor therapy in ten patients with recent-onset refractory reactive arthritis. Arthritis Rheum. 2011;63: 1274-89.
- Espinoza LR1, García-Valladares I. Of bugs and joints: the relationship between infection and joints. Reumatol Clin. 2013 Jul-Aug;9(4):229-38