Arthritis, Reactive

Key Features

Essentials of Diagnosis

• Oligoarthritis, conjunctivitis, urethritis, and mouth ulcers most common features

• Usually follows dysentery or a sexually transmitted infection

• Fifty to 80% of patients are HLA-B27 positive

General Considerations

• Reactive arthritis

  • Precipitated by antecedent gastrointestinal and genitourinary infections

  • Manifests as an asymmetric sterile oligoarthritis, typically of the lower extremities

• Frequently associated with enthesitis

• Extra-articular manifestations are common and include

  • Urethritis

  • Conjunctivitis

  • Uveitis

  • Mucocutaneous lesions

Demographics

• Most common in young men

• The gender ratio: 1:1 after enteric infections but 9:1 with male predominance after sexually transmitted infections

• Associated with HLA-B27 in 80% of White patients and 50–60% of Black patients

Clinical Findings

Symptoms and Signs

• Most cases develop within 1–4 weeks after either a gastrointestinal infection (usually with Shigella, Salmonella, Yersinia, or Campylobacter) or a sexually transmitted infection (with Chlamydia trachomatis or perhaps Ureaplasma urealyticum)

• The spectrum of pathogens known to cause reactive arthritis is broadening to include mycobacterium, staphylococcus, and SARS-CoV-2

• The arthritis is most commonly asymmetric and frequently involves the large weight-bearing joints (chiefly the knee and ankle)

• Sacroiliitis or ankylosing spondylitis is observed in at least 20% of patients

• Systemic symptoms including fever and weight loss are common at the onset of disease

• Mucocutaneous lesions may include

  • Balanitis

  • Stomatitis

  • Keratoderma blenorrhagicum (indistinguishable from pustular psoriasis)

• When present, conjunctivitis is mild and occurs early in disease course

• Anterior uveitis, which can develop at any time in HLA-B27-positive patients, is a more clinically significant ocular complication

• Carditis and aortic regurgitation may occur

Differential Diagnosis

• Gonococcal arthritis

• Psoriatic arthritis

• Ankylosing spondylitis

• Rheumatoid arthritis

• Behçet disease

• Arthritis associated with inflammatory bowel disease

Diagnosis

Laboratory Tests

• HLA B-27 test is useful in the diagnosis

Imaging Studies

• Radiographic signs of permanent or progressive joint disease may be seen in the sacroiliac as well as the peripheral joints

Treatment

Medications

• Nonsteroidal anti-inflammatory drugs (NSAIDs) have been the mainstay of therapy

• Patients who do not respond to NSAIDs may respond to sulfasalazine, 1000 mg twice daily orally or methotrexate 7.5–20 mg per week orally

• Antitumor necrosing factor agents, which are effective in other spondyloarthropathies, may have efficacy in recent-onset disease refractory to NSAIDs, sulfasalazine, and methotrexate

• For chronic reactive arthritis associated with chlamydial infection, combination antibiotics taken for 6 months is more effective than placebo

Outcome

Prognosis

• While most signs of the disease disappear within days or weeks, the arthritis may ...