Reactive arthritis - Seronegative arthritides (spondyloarthropathies)

Reactive arthritis

Definition

Acute or chronic synovitis that occurs less than 6 weeks following infections with various organisms, including Chlamydia, Yersinia, Salmonella, Shigella and Campylobacter species. Reiter’s syndrome is a form of reactive arthritis with the triad of arthritis, uveitis, and urethritis.

Incidence

Unknown but not rare.

Age

Peak at 16–35 years.

Sex

M > F

Aetiology

As with other spondylo-arthritides there is a strong association with HLA B27 (60–80% of patients). Inflammatory arthritis is precipitated by an environmental agent, e.g. sexually acquired non-specific urethritis caused by Chlamydia trachomatis or Ureaplasma urealyticum or enteric infections particularly Shigella,

Yersinia or Salmonella.

Pathophysiology

In early synovitis there is intense hyperaemia with inflammatory infiltration. The arthritis is said to be sterile as bacteria cannot be cultured from joints; however, bacterial DNA and RNA and bacterial macromolecules can be detected in the joints.

Clinical features

Typically there is an abrupt onset of asymmetrical lower limb arthritis, sacroilitis and spondylitis. Achilles tendinitis and plantar fasciitis may also occur. This may have been preceded by a clinical urethritis, prostatitis, cystitis or diarrhoeal disease. Bilateral conjunctivitis and uveitis may also occur.

Investigations

High ESR, anaemia of chronic disease and leucocytosis occur. The synovial fluid white cell count is high. X-rays are initially normal but may show erosions and features similar to ankylosing spondylitis.

Management

Although unlikely to affect the course of arthritis, antibiotics are given for ongoing urethritis. Ophthalmology referral is essential for uveitis and the arthritis is usually managed with nonsteroidal anti-inflammatory drugs. The few patients who develop a chronic arthritis are treated as for rheumatoid arthritis.