Pathophysiology

Immune reaction - RF binds to IgG at the same site at the immune system does

• Autoimmune reaction causing an infiltrate of T-lymphocytes, macrophages, plasma cells
• Macrophages produce cytokines (TNF-alpha,IL-1,IL-6)
• Leads to synovial hypertrophy (pannus formation) - Producing more inflammation
• The inflammation stimulates osteoclasts - Breaking down bones and causing deformities

Risk factors:

• Age between 40-60
• Female
• Genetic predisposition - HLA DRB-1 gene
• Smoking

PC

• presentation usually insidiously develops over a few months
• swollen, painful joints in hands and feet
• stiffness worse in the morning (lasting longer then 30 mins)
• gradually gets worse with larger joints becoming involved

Examination:

• positive 'squeeze test' - discomfort on squeezing across the metacarpal or metatarsal joints