rheumatoid arthritis

see also:

• rheumatology
• arthritis - clinical patterns
• rheumatoid factor
• autoimmune disease

• F:M = 3:1; esp. 4th-6th decades; 20% have an acute presentation; inflammation increased by movement!
• esp. if HLA-DR4; Rh factor +ve in 70%;
• US study of 76,000 women aged 50-79 years presented in 2010¹⁾ suggests that drinking tea increase risk of RhA by 40%, and drinking > 4 cups a day increases risk by 70%. Given the nature of the study, it is also perhaps plausible that women with Rh A drank more tea in the belief that it decreases arthritis. Risk of RhA in this study was not related to caffeine intake or coffee.

• MCPs, PIPs, wrists
  • ⇒ ulnar deviation - subluxation of ext. tendons at MCP jts
  • ⇒ swan-neck - PIP hyperextension & compensatory DIP flexion due to IO contractures &/or shortening of extensor tendons
  • ⇒ boutonniere deformities - PIP fixed flexion contracture with DIP hyperextension due to division of extensor hood with volar slipping of ext. tendon from middle phalanx
  • ⇒ limited dorsiflexion wrist
  • ⇒ z-deformity thumb - MCP flexion & IP hyperextension due to:
    • prolapse of MC head b/n the long & short extensore tendons, or,
    • rupture of thumb flexor
• knees, ankles
  • ⇒ muscle atrophy, Baker's cyst, retrocalcaneal bursae
• 1st & 5th MTPs, subtalar/midtarsal joints
• cervical spine
  • ⇒ degeneration of transverse ligt of atlantoaxial jt
• TMJs
  • ⇒ pain on chewing
• cricoarytenoids
  • ⇒ hoarseness

• tenosynovitis
• s/c nodules
  • esp. elbows
• vasculitis
  • ⇒ skin infarcts
• pulmonary disease:
  • pleurisy, effusions
  • fibrosing alveolitis, interstitial fibrosis,
  • bronchiolitis obliterans
  • pulm. arteritis/hypertension
  • nodules ⇒ cavitation/bronchopleural fistulae/Caplan's syndrome
  • stridor due to crycoarytenoid arthritis or nodules on cords
  • recurrent infections (Sjogren's)
  • iatrogenic: asthma (aspirin)/ allergic finrosing alveolitis (gold); Goodpasture's (penicillamine); interstitial fibrosis (methotrexate, chlorambucil)
• mononeuritis multiplex
• Felty's syndrome:
  • seropos. RhA + splenomegaly + neutropenia ⇒ infections, etc
• ocular:
  • keratoconjunctivitis sicca (in 20-30%) / Sjogren's syndrome
  • episcleritis / scleritis / scleromalacia perforans / scleral nodules &/or vasculitis
  • iatrogenic: corneal opacity/pigmentary retinopathy (chloroquine); cataracts (steroids);
• cardiac:
  • acute pericarditis;
  • insignificant MR;
  • AR due to vasculitis or nodules;
• renal disease:
  • amyloidosis (nephrosis)
  • renal tubular acidosis (in Sjogren's)
  • analgesic nephropathy
  • NSAID-induced usually benign interstitial nephritis ⇒ haematuria +/- proteinuria
  • other iatrogenic: gold/penicillamine: reversible proteinuria/nephrosis/Goodpasture's;
• splenomegaly due to:
  • primary disease manifestation (normal neutrophil count)
  • Felty's syndrome (neutropenia)
  • Sjogren's syndrome
  • amyloidosis
• anaemia due to:
  • active inflammatory “chronic” disease
  • Felty's syndrome
  • iatrogenic - GIT bleed; hypoplastic anaemia; sulphasalazine haemolysis or folate defic.

• methotrexate
• parenteral TNF alpha antagonists such as:
  • adalimumab injection every 2wks
  • etanercept
  • PrismRA employs a predictive model that combines clinical factors, blood tests, and 19 gene patterns to identify the ~60% of patients who are very unlikely to respond to a TNF inhibitor drug. ²⁾
• Janus kinase inhibitors which block the cytokine pathway which activates lymphocytes, such as:
  • oral tofacitinib 5mg bd