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Rheumatism. Rheumocarditis

Rheumatism. Rheumocarditis

1. ACUTE RHEUMATIC FEVER

Etiology

  • MC in children – 5-15 year olds
  • Endemic in Asia, Africa, S.America
  • Triggered by an immune-mediated delayed response to infection with group A strep

Pathogenesis

  • Group A strep have antigens that can cross react with cardiac myosin and sarcolemma membrane protein
  • Antibodies are produced against the strep antigens
    • Cause inflam in the endo, myo and pericardium
    • And in joints and skin
  • Histology
    • Achoff nodules in the heart – pathognomic feature
      • Composed of multinucleated giant cells surrounded by macrophages and T cells
    • Fibrinoid degeneration in the collagen of connective tissue

Clinical features

  • Fever, anorexia, lethargy, arthralgia – 2 weeks after episode of streptococcal pharyngitis
  • Dx made by Jones critera
    • 2 or more major manifestations, or
    • 1 major and 2 minor, and
    • Evidence of preceding strep infx

Carditis

  • Pancarditis
  • Can manifest as breathlessness, palpitations, CP
  • Tachycardia, cardiac enlargement
  • Carey Coombs murmur – soft mid diastolic murmur
    • Due to valvulitis with nodules forming on the MV leaflets
  • Pericardial friction rub

Arthritis

  • Occurs early when ASO titres are high
  • Acute painful, asymmetric, migratory inflam of the large joints (knees, ankles, elbows, wrists)
  • Joints are red, swollen, tender
  • Pain responds to aspirin

Skin lesions

  • Erythema marginatum – red macules that fade in the centre
    • On trunk and proximal extremities, NOT on face
  • Subcutaneous nodules – small, firm, painless on extensor surfaces

Sydenham’s chorea

  • Late neurological manifestation – >3 months after episode of ARF
  • Emotional liability – first feature
  • Involuntary movements of hand, feet, face
  • Explosive speech

Diagnosis – see box

Treatment

  • Benzyl pen/oral phenoxymethylpen to eliminate residual strep infx (use clarithromycin if allergy)
  • Bed rest and supportive treatment
  • Aspirin – pain relief confirms diagnosis of acute rheumatic fever
  • Corticosteroids
  • Long term prophylaxis against further strep infx – benzathine pen (sulfadiazine/erythromycin if pt is allergic to pen

2. CHRONIC RHEUMATIC HEART DISEASE

  • Develops in 50% of pts with ARF with carditis
  • MC in women
  • Mitral valve is affected in 90% of cases

Pathology

  • Progressive fibrosis of heart valves
    • Fusion of MV commissures and shortening of the chordae tendineae – leads to mitral stenosis
  • After valve is damaged, altered hemodynamic stress further increases the damage
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