Acute Rheumatic Fever

It is an immunological disorder which occurs when antibiotics produced against streptococcal cell wall proteins & sugars react with connective tissue of the body

Causative Organism

Group A beta hemolytic Streptococci (GABS)

Epidemiology

Age – 5 – 15 years
Sex – Equally affects both sexes
Predisposing factors – Poor socio-economic conditions, unhygienic living conditions & overcrowding

Pathogenesis

GABS Pharyngitis → Antibiotics formed against streptococcal antigen → Molecular Mimicry between M Protein of GABS & Myosin in Myocardium → Antibodies attach to the valves of heart
Latent period between sore throat and clinical manifestations is 10 days – several weeks
Aschoff Bodies are pathognomic of Acute Rheumatic Fever (ARF)

Clinical Features

Major criteria

Arthritis

Early manifestation.

Characteristics

Migratory polyarthritis
Involves large joints (ankle, knee, wrist, elbow)
There is swelling, pain, warmth & tenderness associated
Responds well to salicylates

Carditis

90% of the cases, an irreversible condition. Early manifestation (within 2 weeks of onset).

Characteristics

Pancarditis – Pain in precordial area
Pericarditis – Pericardial rub and effusion, ECHO shows ST & T changes
Myocarditis – Resting tachycardia, Soft S1, S3 gallop seen
Endocarditis –
- - Mitral systolic murmur (Pan systolic murmur of mitral regurgitation)
  - Carey Coombs (Mitral diastolic) murmur heard
  - Aortic diastolic murmur
  - Tricuspid regurgitation may also be present

Chorea

Late Onset after 6 months

Characteristics

Syndeham’s Chorea or St. Vitus Dance
Semi purposive, involuntary movements with jerky speech
Affects girls more. Affected child are emotionally labile
Pronator & Spooning sign, Darting tongue, Milk maids grip

Subcutaneous Nodules

Early Manifestation

Characteristics

Hard, painless, freely mobile nodules present on extensor aspects of bony prominences, associated with carditis

Erythema Marginatum

Early Manifestation

Over the trunk, non- itching.
Starts as a red spot with pale center
Coalesce with adjacent spots to form a serpiginous outline

Minor

Fever – >38° C
Arthralgia – Subjective Pain

Essential

Evidence of recent streptococcal infection

Characteristics

ASO titre that goes up to 250U/dl
Positive throat culture

Investigation

Acute Phase Reactants
- Leukocyte count – 10,000 – 15,000 / mm³
- Elevated ESR >30 mm/hr
- Elevated CRP (subsides with steroids) > 3 mg/dl
ECG – Prolonged PR > 0.16s
Previous Streptococcal Infection
- Anti Streptolysin O Antibody
- Anti DNase B
- Throat culture
Chest X-Ray – To see cardiomegaly
ECHO – To assess status of valves

Treatment

Bed Rest
Penicillin –
- 1 Inj. benzathine penicillin ( < 30 kg = 6,00,000 U, ≥30 kg = 12,00,000 U)
- Or, Penicillin V 250mg orally QiD x 10 days
- Or, for Penicillin allergy, Erythromycin 250mg orally QiD x 10 days
Suppressive therapy –
- 12 weeks therapy
- Carditis with congestive cardiac failure – Corticosteroids
- Carditis without congestive cardiac failure – Aspirin or Corticosteroids
- No Carditis – Aspirin
- Aspirin – 90-120 mg / kg daily x 10 weeks then tapered for next 2 weeks
- Prednisolone – 2 mg/ kg daily x 3 weeks then tapered for next 9 weeks
Surgical replacement of aortic or mitral valve indicated in severe carditis.

Prevention

Primary –
- Prompt identification of sore throat
- Rapid confirmation of streptococcal etiology
- Availability of penicillin
Secondary –
- Duration of Secondary Prophylaxis –
  - No Carditis – 5 yr / 25 yr of age, whichever is longer
  - Mild to Moderate & Healed carditis – 10 yr/ 25 yr of age, whichever is longer
  - Severe disease or post intervention patients – Lifelong. One may opt for secondary prophylaxis up to age of 40 years.
Regimen –
- Penicillin –
  - 2 Inj. benzathine penicillin. Interval of 3-4 weeks required between 2 doses ( < 30 kg = 6,00,000 U, ≥30 kg = 12,00,000 U)
  - Or, Penicillin V 250mg orally BD
  - Or, for Penicillin allergy, Erythromycin 250mg orally BD