Makindo Medical Notes

Related Subjects: | Monoarticular Arthritis | Polyarticular Arthritis | Seronegative Spondyloarthropathies | Ankylosing Spondylitis | Enteropathic Spondyloarthritis | Reactive Arthritis | Psoriatic Arthritis

Seronegative spondyloarthropathies refer to inflammatory arthritis of the spine and/or joints without the presence of rheumatoid factor (RF) or anti-cyclic citrullinated peptide (CCP) antibodies.

About: Characteristics

• Axial skeleton involvement (spine and sacroiliac joints)
• Insidious onset of inflammatory lower back pain
• Typically affects individuals aged 45 or younger
• Asymmetrical peripheral arthritis
• Inflammation at the enthesis (site where tendons or ligaments insert into bone)
• Strong association with HLA-B27, though the clinical significance varies

Aetiology

• Close relationship with HLA-B27, though not all individuals with this gene develop the disease

Types of Seronegative Spondyloarthropathies

• Axial spondyloarthritis/Ankylosing spondylitis : Primarily affects the spine, leading to spinal stiffness and fusion.
• Reactive arthritis (e.g., Reiter's syndrome): Triggered by an infection (e.g., sexually acquired or post-dysentery).
• Psoriatic arthritis : Associated with psoriasis, presenting with characteristic skin and nail changes.
• Enteropathic arthritis : Occurs in association with inflammatory bowel diseases like ulcerative colitis (UC) and Crohn’s disease (CD).

Major Criteria

• Inflammatory back pain : Lower back pain accompanied by morning stiffness, typically relieved by exercise but not by rest.
• Oligoarthritis : Asymmetrical involvement of joints, particularly in the lower limbs (knees, ankles).

Minor Criteria

• Enthesitis : Inflammation where tendons or ligaments insert into the bone (e.g., Achilles tendon).
• Alternating buttock pain
• Preceding symptomatic infection (e.g., urogenital or gastrointestinal infection)
• Presence of psoriasis or Crohn-like lesions in the gut
• Dactylitis : Inflammation of an entire finger or toe ("sausage digit"), often seen in psoriatic arthritis.
• Anterior uveitis : Inflammation of the eye (iritis) can also be present.
• Family history of spondyloarthritis

Investigations

• FBC : Look for signs of anaemia or raised white cell count.
• CRP/ESR : Raised inflammatory markers, indicating active disease.
• HLA-B27 : Presence can support diagnosis but is not definitive.
• Imaging : CT/MRI : Radiographic evidence of sacroiliitis, including sclerosis, erosions, and eventual fusion of the sacroiliac joints. MRI can detect sacroiliitis earlier than X-ray or CT.
• Tests for urogenital or gastrointestinal infection in reactive arthritis cases.

Management

• Physiotherapy : Regular stretching and strengthening exercises, particularly in the morning, to maintain flexibility and prevent spinal deformities (e.g., syndesmophyte formation).
• NSAIDs : Slow-release NSAIDs taken at night can help reduce morning stiffness and pain.
• Orthopaedic surgery : Considered in severe cases to correct spinal deformities.
• Sulfasalazine and Methotrexate : Effective for peripheral joint involvement but less effective for spinal disease.
• TNF-alpha inhibitors : biological agents can significantly reduce pain and inflammation in both spinal and peripheral joint disease.
• Uveitis management : May require topical or systemic corticosteroids for inflammation control.
• Treatment of infection : For cases of reactive arthritis, treat underlying infections such as Chlamydia.

References

• Ankylosing Spondylitis: A Review by Farrouq Mahmood and Philip Helliwell