Arthritis, Rheumatoid

Basics

Description

  • Systemic inflammatory autoimmune disorder that attacks the joints:
    • Symmetric, proliferative synovitis
    • Progressive joint erosion and destruction
    • Commonly involves metacarpophalangeals (MCPs) and proximal interphalangeals (PIPs)
    • Moves distal to proximal
  • 40% develop extra-articular disease
  • 3:1 female-to-male ratio
  • Typically diagnosed between ages 30 and 60

Pediatric Considerations

Juvenile rheumatoid arthritis (RA) (now known as juvenile idiopathic arthritis) is a distinct entity (see “Arthritis, Juvenile Idiopathic”)

Etiology

  • Etiology is unknown
  • Major environmental risk factor is smoking
  • Healthy diet and physical fitness are protective factors
  • Prevalence is about 1% in North America and European ethnic groups, slightly lower in other populations
  • HLA-DRB1 is considered the major genetic susceptibility locus in RA:
    • Strong associations between many other alleles are also recognized

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