Summary

  • The seronegative spondyloarthropathies are a collection of joint disorders in which patients are Rheumatoid factor negative, including reactive arthritis, psoriatic arthritis, enteropathic arthritis and ankylosing spondylitis.
  • Genetics - Significant association with HLA-B27

 

Clinical features

  • Asymmetrical inflammatory arthritis of peripheral joints/back
  • Morning stiffness
  • Enthesopathy - e.g. achilles tendonitis, plantar fasciitis 
  • Sacroiliitis 
  • Extra-articular manifestations

 

Reactive arthritis (Reiter’s syndrome)

Clinical Features

  • Characterised by the triad of:
    • Conjunctivitis
    • Urethritis
    • Asymmetrical oligoarthritis
    • Memory aid: Patients with ReA can’t see, can’t pee and can’t climb a tree.
  • Symptoms usually last for less than 12 months before resolution

Causes

  • Reactive arthritis is typically preceded by an infection of the GI or GU tracts
    • Post-STI (especially men) – Chlamydia trachomatis
      • This is SARA – sexually acquired reactive arthritis 
    • Post-dysentery – campylobacter, Shigella, Salmonella, Yersinia 

Management 

  • 1st Line: NSAIDs (+/- paracetamol or intra-articular steroids)
    • And treat underling disease if appropriate (i.e. ABx for STI)
  • 2nd line: If severe disease, sulfasalazine/ methotrexate are rarely used 

   

Psoriatic arthritis

10-20% of patients with cutaneous psoriasis will develop psoriatic arthritis. Patients may also have dactylitis, and enthesitis. 

Investigations

X-ray: 

  • DIPs are most affected - important differentiating factor from RA (which spares the DIPs) 
  • Juxta-articular periostitis
    • Pencil in a cup appearance

Management

  • As per the management of rheumatoid arthritis (i.e. DMARDs are the mainstay)

  

Enteropathic arthritis

Enteropathic arthritis occurs in patients with IBD (Crohn’s or ulcerative colitis)

Clinical features

  • Features of Crohn’s/UC may be present in question vignette’s i.e. history of diarrhoea, weight loss, abdominal pain, PR bleeding etc. 
  • Peripheral arthritis - Transient asymmetrical oligoarthritis, typically affecting the lower limbs
  • Axial arthritis - Sacroiliitis - gradual onset low back pain, radiating into legs, chronic. 
  • Enthesopathy – Achilles tendonitis, plantar fasciitis
  • Extra-articular manifestations

  

Ankylosing Spondylitis

Genetics

  • Significant association with HLA-B27 (positive in 90% of patients)

Clinical features

Presentation

  • Typically a young male patient age 20-35 
  • Lower back pain is predominant symptom
    • May be worse at night 
  • Morning stiffness, improves with exercise 

Examination findings

  • Reduced lateral flexion and forward flexion
    • Schober’s test – failure to increase by > 5cm

Extra-articular features - Tip: “The A’s of Ankylosing spondylitis”

  • Anterior uveitis
  • AVN block on ECG (1st degree HB)
  • Aortic regurgitation - early diastolic murmur
  • Amyloidosis A
  • Apical lung fibrosis

Investigations

  • 1st Line: plain XR of sacroiliac joint - sacroiliitis, squaring of the vertebra, syndesmophytes and a bamboo spine 
  • 2nd line: If XR is negative but clinical suspicion - MRI L/S spine
  • Other:
    • Spirometry – restrictive pattern (fibrosis)
    • As above, HLA-B27 is NOT used in the diagnostic work up 

Management

  • Pharmacological
    • 1st Line: NSAIDs
    • DMARDs (inc. TNF-inhibitors) are only effective for peripheral joint arthritis (not back pain/stiffness). 
  • Exercise is extremely important