👐 Rheumatoid Arthritis

🔑 Key Learning

• Chronic autoimmune symmetrical polyarthritis, classically affecting small joints (MCPs, PIPs, wrists) but sparing the DIPJs
• Presents with morning stiffness > 1 hour, joint swelling and pain
• Antibodies: RhF, anti-CCP
• Managed with DMARDs and bridging steroids; biologics in refractory cases

🧬 Pathophysiology

• Autoimmune synovial inflammation → joint destruction
• Progressive cartilage and bone erosion if untreated

👀 Clinical Features

• Peak onset: 30–50 years, Female > Male (3:1)
  • HLA-DR4 association
• Symmetrical small joint pain/swelling: MCP, PIP, wrists, MTPs
  • Spares DIPJs
• Morning stiffness > 1 hour
• Joint deformities in advanced disease:
  • Boutonnière deformity
  • Swan-neck deformity
• Rheumatoid nodules (extensor surfaces)
• Positive squeeze test
• Warm, boggy joints

🧪 Investigations

• Bloods:
  • 1st line: Rheumatoid factor - positive in 7/10 people with RA
    • An IgM antibody which reacts with IgG
    • Prognostic marker - high RhF levels associated with progressive disease
  • 2nd line: If RhF negative, measure anti-cyclic citrullinated peptide antibodies (anti-CCP)
  • CRP/ESR are commonly elevated
• XR: Juxtaarticular osteoporosis

💥 Management of Flares

• 1st Line: Short-term treatment with steroids
  • Intra-articular glucocorticoid if localised flare
  • IM glucocorticoid if IA is not possible - methylprednisolone, triamcinolone 
  • PO glucocorticoid if not practical to give IM
• Consider offering an NSAID for short term symptomatic relief with PPI

💊 Long-term Management

• 1st Line: DMARD monotherapy (methotrexate, sulfasalazine, leflunomide) at diagnosis
  • Methotrexate is commonly given 1st line for RA
  • Consider hydroxychloroquine for palindromic rheumatism
  • Consider bridging steroid when commencing DMARD
• 2nd Line: Combination of 2 DMARDs
• 3rd Line: Add biological DMARDs:
  • TNF inhibitors: etanercept, infliximab, adalimumab
  • Other biologics: rituximab, abatacept

🧪 DMARD Side Effects

🤰 RA in Pregnancy

• Safe DMARDs: Sulfasalazine, Hydroxychloroquine (SHafe in pregnancy))
• Avoid: Methotrexate, Leflunomide

🫁 Extra-Articular Features

🫁 Respiratory

• Pulmonary fibrosis
• Pleural effusions (exudative)
• Caplan syndrome (RA + coal dust exposure)
• Pulmonary nodules
• Bronchiolitis obliterans

👁 Ocular

• Keratoconjunctivitis sicca (most common)
• Scleritis / episcleritis
• Corneal ulcers

❤️ Other

• Accelerated CV disease
• Osteoporosis
• Depression
• Felty's syndrome (RA + splenomegaly + neutropenia)
• AA amyloidosis

🔄 Palindromic Rheumatism

• Relapsing/remitting monoarthritis (large joints)
• Tx: Hydroxychloroquine, other DMARDs if required

📝 Exam Clues & Clinchers

• Symmetrical small joint pain, sparing DIPJs, with stiffness > 1 hour in morning
• Antibodies: RhF +ve  - if negative check anti-CCP = highly specific
• Treatment: Methotrexate is 1st line; avoid in pregnancy