Reactive arthritis
Reactive arthritis is a sterile, human leukocyte antigen B27 (HLA-B27)-associated spondyloarthritis that follows a genitourinary or enteric infection by 1 to 4 weeks, producing asymmetric lower-limb oligoarthritis, enthesitis, and the urethritis-conjunctivitis-arthritis triad. It is a clinical diagnosis of a culture-negative joint. First-line treatment is an NSAID such as piroxicam for at least 2 weeks, escalating to glucocorticoids and then sulfasalazine or a tumor necrosis factor (TNF) inhibitor for disease persisting beyond 3 to 6 months.
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What this article covers
- Overview
Definition: a sterile, spondyloarthritis-family joint disease that develops as a host immune response to a preceding genitourinary or gastrointestinal infection, not direct infection of the joint; it is an aseptic arthritis.
- Epidemiology
Proportion of spondyloarthritis: only about 2% of patients within the spondyloarthritis category, the least common subtype.
- Risk factors
HLA-B27 positivity: the dominant host susceptibility factor.
- Pathophysiology
Aseptic, host-driven inflammation: an aseptic arthritis induced by a host immune response to an infectious agent rather than direct bacterial invasion of the joint; the synovium inflames without the…
- Clinical features
Diagnostic pattern: an asymmetric, pauciarticular arthritis of the lower-extremity large joints, most commonly the knee, ankle, and wrist, arising 1 to 4 weeks (typically 2 to 3 weeks) after a…
- Differential diagnosis
Septic arthritis: also acute monoarthritis or oligoarthritis with fever, but synovial leukocyte counts typically exceed 50,000/uL and often 100,000/uL with a positive gram stain or culture, unlike the culture-negative fluid here.
- Diagnosis
First, arthrocentesis to establish this as a clinical diagnosis of a sterile joint: cell count, gram stain, and culture are obtained on any acutely swollen joint to exclude septic arthritis and…
- Management
First, an NSAID at anti-inflammatory dosing for at least 2 weeks, then reassess response: Piroxicam 20 mg PO once daily.
- Complications
Erosive joint disease: most often at the metatarsophalangeal joints, with permanent structural damage.
- Prognosis
Typical course: most flares last 6 weeks to 6 months, though manifestations can persist up to 1 year.
- Prevention
Prompt treatment of genitourinary triggers: treating documented Chlamydia trachomatis urethritis or cervicitis (azithromycin 1 g PO single dose or doxycycline 100 mg PO twice daily for 7 days) and…
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