Rheumatic fever

• Still common in developing countries
• Peak incidence 5-15 years
• Tends to reoccur unless prevented
• Pharyngeal infection with Lancefield Group A ?-haemolytic strep triggers rheumatic fever 2-4 weeks later in the 2% of the susceptible population
• Due to antibody to the carbohydrate cell wall cross reacting with valve tissue

Diagnosis depends on the Jones criteria

• Must have evidence of recent strep infection, 1 major criteria and 2 minor criteria
  • Evidence of strep infection;
  • Recent streptococcal infection
    • History of scarlet fever
    • Positive throat swab
    • Increased in anti-streptolysin O
    • Increase in DNase B titre
  • Major criteria
    • Carditis – tachycardia, murmurs, pericardial rub, CCF, cardiomegaly, conduction defects
    • Arthritis – migratory flitting polyarthritis that usually affects larger joints
    • Subcutaneous nodules – small mobile painless nodules on extensor surface of joints and spine
    • Erythema marginatum – geographical type rash with red raised edges and clear centre, occurs mainly on trunk, thighs and arms
    • Sydenham’s chorea (St Vitus’ dance) – unilateral or bilateral involuntary semi purposeful movements
  • Minor criteria
    • Fever
    • Raised ESR or CRP
    • Arthralgia
    • Prolonged PR interval
    • Previous rheumatic fever

Management

• Best rest until CRP normalises
• Benxypenicillin IM stat then penicillin V
• Analgesia for arthritis/carditis – aspirin, NSAIDs
• Immobilse joints in severe arthritis
• Haloperidol or diazepam for chorea

Prognosis

• 60% with carditis develop chronic rheumatic heart disease
• Acute attacks generally last 3months
• Reoccurrence may be precipitated by another strep infection, pregnancy or the pill
• Cardiac sequelae, valves affected, mitral (70%), aortic (40%), tricuspid (10%), pulmonary valves (2%)
• Incompetent valves develop during attack and stenosis later