M08.027.003 Seronegative spondyloarthropathies

Seronegative spondyloarthropathies (SpA) are a group of inflammatory rheumatic diseases that share several key characteristics. Understanding these characteristics and the different subtypes of SpA is crucial for medical students.

Key Features of Seronegative Spondyloarthropathies

• Rheumatoid Factor Seronegativity: Patients with SpA test negative for rheumatoid factor, an antibody commonly found in rheumatoid arthritis.
• Sacroiliac Joint Involvement: Inflammation of the sacroiliac joints, located in the lower back where the spine connects to the pelvis, is a hallmark feature of SpA.
• HLA-B27 Association: An increased prevalence of the human leukocyte antigen B27 (HLA-B27) gene is observed in SpA patients, suggesting a genetic predisposition.

Key Features of Seronegative Spondyloarthropathies

Points to Remember:

• While these features are common, SpA can manifest differently in each patient.
• Differential diagnosis from other inflammatory conditions like rheumatoid arthritis is crucial.

Subtypes of Seronegative Spondyloarthropathies

Several subtypes of SpA exist, each with its own clinical presentation:

• Ankylosing Spondylitis:
  • Predominantly affects young men with HLA-B27 (up to 90% of cases).
  • Involves the sacroiliac joints and spine, potentially leading to spinal fusion (“bamboo spine”).
  • May be associated with inflammatory bowel disease.
• Reactive Arthritis:
  • Characterized by a classic triad of:
    • Conjunctivitis (eye inflammation)
    • Urethritis (urinary tract inflammation)
    • Arthritis (often affecting ankles and knees)
  • More common in males, typically with onset in the 20s-30s.
  • Often follows a sexually transmitted infection (STI) or bacterial dysentery.
• Enteropathic Arthritis:
  • Develops in 10-20% of patients with inflammatory bowel disease (e.g., Crohn’s disease, ulcerative colitis).
• Psoriatic Arthritis:
  • Affects 5-10% of patients with psoriasis, a chronic skin condition.
  • Often presents as a mild, slowly progressive arthritis with similarities to rheumatoid arthritis.

Table 2. Subtypes of Seronegative Spondyloarthropathies

Points to Remember:

• Each subtype has its own diagnostic criteria and treatment approaches.
• Early diagnosis and management are crucial to prevent long-term complications.

Bibliography

• [Insert Textbook of Internal Medicine reference on Seronegative Spondyloarthropathies]
• [Insert Journal article reference on recent advancements in SpA diagnosis or treatment]