Reactive arthritis is an acute spondyloarthropathy
Spondyloarthropathy associated with urethritis or cervicitis, conjunctivitis, and mucocutaneous lesions (previously called Reiter syndrome) is one type of reactive arthritis.
Etiology of Reactive Arthritis
Two forms of reactive arthritis are common: sexually transmitted and dysenteric.
The sexually transmitted form occurs primarily in men aged 20 to 40. Genital infections with Chlamydia trachomatis are most often implicated.
Men or women can acquire the dysenteric form after enteric infections, primarily Shigella, Salmonella, Clostridioides difficile, Yersinia, or Campylobacter.
Bacille Calmette-Guerin injection for bladder cancer has also been reported to trigger reactive arthritis.
In approximately 40% of cases, infectious pathogens cannot be identified (1).
Reactive arthritis is postinfectious arthritis. Although there is evidence of microbial antigens in the synovium, organisms cannot be cultured from joint fluid.
Etiology reference
1. Fendler C, Laitko S, Sörensen H, et al: Frequency of triggering bacteria in patients with reactive arthritis and undifferentiated oligoarthritis and the relative importance of the tests used for diagnosis. Ann Rheum Dis. 2001;60(4):337-343. doi:10.1136/ard.60.4.337
Epidemiology of Reactive Arthritis
The prevalence of the human leukocyte antigen B27 (HLA-B27) allele in patients with reactive arthritis may be as high as approximately 80% (PMID 34144605), compared with estimates from the general population with estimates of 7% in healthy controls (1, 2), thus supporting a genetic predisposition.
Compared to patients without HLA-B27 allele, patients with HLA-B27 allele have more severe arthritis, extraarticular manifestations, and more prolonged courses.
Epidemiology references
1. Costantino F, Talpin A, Said-Nahal R, et al: Prevalence of spondyloarthritis in reference to HLA-B27 in the French population: results of the GAZEL cohort. Ann Rheum Dis. 2015;74(4):689-693. doi:10.1136/annrheumdis-2013-204436
2. Bentaleb I, Abdelghani KB, Rostom S, Amine B, Laatar A, Bahiri R. Reactive Arthritis: Update. Curr Clin Microbiol Rep. 2020;7(4):124-132. doi:10.1007/s40588-020-00152-6
Symptoms and Signs of Reactive Arthritis
Reactive arthritis can range from transient monarticular arthritis to a severe, multisystem disorder. Constitutional symptoms may include fever, fatigue, and weight loss. Arthritis may be mild or severe. Joint involvement is generally asymmetric and oligoarticular or polyarticular, occurring predominantly in the toes and large joints of the lower extremities and may include large knee effusions. Back pain may occur, usually with severe disease. Joint damage occurs rarely. Axial involvement is more often reported in patients with positive HLA-B27 and usually is asymmetric with large and bulky syndesmophytes.
Enthesopathy (inflammation at tendinous insertion into bone—eg, plantar fasciitis, digital periostitis, Achilles tendinitis) is common and characteristic.
Mucocutaneous lesions—small, transient, relatively painless, superficial ulcers—commonly occur on the oral mucosa, tongue, and glans penis (balanitis circinata). Particularly characteristic are vesicles (sometimes identical to pustular psoriasis) of the palms and soles and around the nails that become hyperkeratotic and form crusts (keratoderma blennorrhagicum). Keratoderma blennorrhagicum can also include erythema, plaques, and scaling. Nails may become dystrophic. Erythema nodosum has also been reported in reactive arthritis, especially after Yersinia infection.
The ulcers in this photo are shallow and relatively painless.
© Springer Science+Business Media
This photo shows extensive psoriatic plaques, generalized erythema, and marked scaling on the palms in a patient with reactive arthritis.
© Springer Science+Business Media
This photo shows plaques, marked erythema, and scaling of the skin in a patient with reactive arthritis.
© Springer Science+Business Media
This image shows dystrophic nail changes resulting from reactive arthritis.
Image courtesy of Karen McKoy, MD.
The ulcers in this photo are shallow and relatively painless.
© Springer Science+Business Media
This photo shows extensive psoriatic plaques, generalized erythema, and marked scaling on the palms in a patient with reactive arthritis.
© Springer Science+Business Media
This photo shows plaques, marked erythema, and scaling of the skin in a patient with reactive arthritis.
© Springer Science+Business Media
This image shows dystrophic nail changes resulting from reactive arthritis.
Image courtesy of Karen McKoy, MD.
Urethritis may develop 7 to 14 days after sexual contact (or occasionally after dysentery); low-grade fever, conjunctivitis, and arthritis develop over the next few weeks. Not all features may occur, so incomplete forms need to be considered. In men, the urethritis is less painful and productive of purulent discharge than acute gonococcal urethritis and may be associated with hemorrhagic cystitis or prostatitis. In women, urethritis and cervicitis may be mild (with dysuria or slight vaginal discharge) or asymptomatic.
Conjunctivitis is the most common eye lesion. It usually causes mild eye redness and grittiness, but keratitis and anterior uveitis can develop also, causing eye pain, photophobia, and tearing.
Rarely, cardiovascular complications (eg, aortitis, aortic insufficiency, cardiac conduction defects), pleuritis, and central nervous system or peripheral nervous system symptoms develop.
Diagnosis of Reactive Arthritis
Typical arthritis
Symptoms of antecedent gastrointestinal or genitourinary infection
One other extra-articular feature
Reactive arthritis should be suspected in patients with acute, asymmetric arthritis affecting the large joints of the lower extremities or toes, particularly if there is enthesitis, dactylitis, or a history of an antecedent diarrhea or dysuria.
Diagnosis is ultimately clinical and requires the typical peripheral arthritis with symptoms of genitourinary or gastrointestinal infection or one of the other extra-articular features. Because these features may manifest at different times, definitive diagnosis may require several months. Serum and synovial fluid complement levels are high, but these findings are not usually diagnostic and need not be measured.
Disseminated gonococcal infection
Psoriatic arthritis can simulate reactive arthritis, causing similar skin lesions, uveitis, and asymmetric arthritis. However, psoriatic arthritis often affects mostly the upper extremities and especially the distal interphalangeal joints, may be abrupt in onset but may also develop gradually, and tends not to cause mouth ulcers or symptoms of genitourinary or gastrointestinal infection.
Treatment of Reactive Arthritis
Nonsteroidal anti-inflammatory drugs (NSAIDs)
Supportive measures
C. trachomatis, as used to treat rheumatoid arthritis
Local injection of depot corticosteroids for enthesopathy or resistant oligoarthritis may relieve symptoms. Physical therapy aimed at maintaining joint mobility is helpful during the recovery phase. Anterior uveitis is treated as usual, with corticosteroid and mydriatic eye drops to prevent scarring. Conjunctivitis and mucocutaneous lesions require only symptomatic treatment.
Screening for human immunodeficiency virus (HIV) and other sexually transmitted infections and treating sex partners are recommended.
Prognosis for Reactive Arthritis
Reactive arthritis often resolves in 3 to 4 months, but up to 50% of patients experience recurrent or prolonged symptoms over several years, especially if induced by chlamydial infection and in patients with positive HLA-B27 alleles. Joint, spinal, or sacroiliac inflammation or deformity may occur with chronic or recurrent disease. Some patients become disabled.
Key Points
Reactive arthritis is a form of spondyloarthropathy that is triggered by infection and typically occurs after a sexually transmitted or enteric infection.
Manifestations can include arthritis (usually asymmetric and involving large lower extremity joints and toes), enthesopathy, mucocutaneous lesions, conjunctivitis, and nonpurulent genital discharge (eg, urethritis, cervicitis).
Confirm the diagnosis with typical arthritic findings plus either symptoms or history of recent genitourinary or gastrointestinal infection or a characteristic extra-articular finding.
