Rheumatic Fever

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Introduction

  • A result of abnormal reaction of antibodies developed against antigens of group A β- haemolytic streptococcus
  • Infection is usually of the throat; occasionally the skin in a sensitized individual
  • Antigen-Antibody complex damages the heart (endocardium, myocardium and pericardium)
  • Commonest streptococcal strains in Africa are C and G

Clinical features

Duckett-Jones' diagnostic criteria

Major:

  • Carditis
  • Sydenham's chorea
  • Erythema marginatum
  • Subcuoeous nodules
  • Arthritis (migratory polyarthritis)

Minor:

  • Fever
  • Leucocytosis
  • Arthralgia
  • Raised ESR
  • Raised ASO titre (> 200 IU)
  • Prolonged PR interval

Supporting evidence of antecedent group A streptococcal infection:

  • Positive throat culture or rapid streptococcal antigen

Diagnosis

2 major criteria

Or:

1 major plus 2 (or more) minor criteria

Differential diagnoses

  • Malaria
  • Viral infection
  • Pyrexia of undetermined origin
  • Connective tissue disease

Complications

  • Rheumatic heart disease
  • Arrhythmias
  • Cardiac failure

Investigations

  • Full Blood Count and differentials
  • ASO titre
  • ESR
  • Electrocardiograph
  • Echocardiography
  • Chest radiograph
  • Throat swab for microscopy, culture and sensitivity

Treatment goals

  • Relieve symptoms
  • Treat the bacterial throat infection
  • Reduce or abolish inflammatory process
  • Treat cardiac failure if present

Non-drug treatment

  • Bed rest

Drug treatment

Antibiotics:

  • Penicillin V
  • Adult: 500 mg orally every 6 hours, increased up to 1g 6 hourly in severe infections
  • Child:
    • 1 month - 1 year: 62.5 mg orally every 6 hours increased in severe infection to ensure at least 12.5 mg/kg/dose
    • 1 - 6 years: 125 mg every 6 hours increased in severe infection to ensure at least 12.5 mg/kg/dose
    • 6 - 12 years: 250 mg every 6 hours, increased in severe infection to ensure at least 12.5 mg/kg/dose
    • 12 - 18 years: 500 mg every 6 hours, increased in severe infection up to 1g/dose

Or

  • Erythromycin
  • Adult and child over 8 years: 250 - 500 mg orally every 6 hours or 500 mg - 1 g every 12 hours; up to 4 g daily in severe infections
  • Child:
    • Up to 2 years: 125 orally mg every 6 hours
    • 2 - 8 years: 250 mg every 6 hours; doses doubled for severe infections

 

  •  Salicylates
    • Aspirin (acetylsalicylic acid)
    • Adult: 300 mg - 1 g orally every 4 hours after food; maximum dose in acute conditions 8 g daily
    • Child: not recommended for use
  • Steroids (if salicylates are ineffective)
    • Prednisolone
    • Initially, up to 10 - 20 mg orally daily; up to 60 mg daily in severe disease (preferably taken in the morning after breakfast); dose can often be reduced within a few days, but may need to be continued for several weeks or months. Maintenance 2.5 -15 mg orally daily

Prophylaxis against rheumatic fever

Benzathine penicillin 720 mg (1.2 million units) intramuscularly 3 - 4 weekly until the age of 25 years or for life

Notable adverse drug reactions, contraindications and caution

  • Penicillin: anaphylactic reaction
  • Salicylates; steroids: peptic ulceration
  • Cushingoid effects are increasingly likely with doses of prednisolone above 7.5 mg daily

Prevention

  • Good sanitation.
  • School surveys - identify carriers of streptococcus and treat
  • Secondary prevention and prophylaxis against endocarditis