Acute rheumatic fever - Pediatrics

Question 1

Risk factors of Acute rheumatic fever

Answer 1

 Low socioeconomic standard: poverty, poor hygiene, medical deprivation.
 Age: in school aged children (5-15 Years): Pharyngitis is most common in this age group.
 Genetic predisposition: It may predispose to the occurrence of the disease (+ve family history)

Question 2

Pathogenesis of Acute rheumatic fever (ARF) (A++)

Answer 2

-It is poorly understood.
-The most acceptable theory is the cross-reactivity.
-Due to Antigenic similarity between some components of GAS (e.g. M protein) and some proteins in human tissues( Heart, Joints, Brain, skin) , antibodies that produced against (GABHS) cross react with human tissues producing immune complex that start inflammatory process that cause damage to human tissue .
-It occurs after a latent period of 2-4 Weeks of (GABHS) infection.

Question 3

Clinical presentation of ARF (A++)

Answer 3

History
1. History of streptococcal pharyngitis, 1 to 5 weeks (average, 3 weeks) before the onset of symptoms, is common.
2. Pallor, malaise, easy fatigability, and other history, such as epistaxis (5%–10%) and abdominal pain, may be present.

Manifestation:
❖ ARF is a multi-system disease with several clinical and laboratory manifestations.
❖ Fever and joint pain are the most common manifestations.
❖ Manifestations with high specificity for ARF are named Major criteria and manifestations with low specificity are named Minor criteria
❖ Five major criteria named jones criteria (Migratory polyarthritis, Carditis, Rheumatic chorea, Erythema marginatum, Subcutaneous nodules)
❖ Minor criteria of rheumatic fever:
* Clinical:
o Fever: usually > 38.5
o Arthralgia (can’t be used as minor criteria in presence of arthritis)
* Laboratory
o Prolonged P-R interval (can’t be used as minor criteria in presence of carditis)
o Elevated acute phase reactants: either all or one is positive → it is one criterion,
✓ Elevated ESR
✓ Positive C-reactive protein
✓ Leucocytosis

Question 4

Diagnosis of Rheumatic fever (A++)

Answer 4

i:
Initial attack of ARF:
* Two major manifestations + Evidence of recent streptococcal infection or
* One major +2 minors manifestations + Evidence of recent streptococcal infection

Recurrent attack of ARF: (It needs a reliable past history of ARF or established RHD)
* Two major manifestations + Evidence of recent streptococcal infection or
* One major +2 minors manifestations + Evidence of recent streptococcal infection
* Three minor manifestations + Evidence of recent streptococcal infection

ii- Special considerations:
1- Arthralgia is not considered as minor criteria in presence of arthritis..
2-  P-R is not considered as minor criteria in presence of carditis.
3- Rheumatic chorea alone diagnose Rh.fever after exclusion of other causes of chorea.
4- The inclusion of polyarthralgia or Mono-arthritis as a major manifestation is applicable only after careful consideration and exclusion of other causes of arthralgia and mono-arthritis respectively.

Question 5

Complications of Rheumatic fever

Answer 5

1- Permanent valvular lesions (rheumatic heart disease)
2- Infective endocarditis.
3- Heart failure
4- Arrhythmia
5- Growth retardation and emaciation.

Question 6

Treatment of rheumatic fever (A++)

Answer 6

1. Bed rest: in cases of carditis & heart failure till ESR is normal and heart failure is controlled.
2. Diet: frequent small feeds and low salt diet in cases with heart failure.
3. Eradicate streptococcal infection:
   o Single dose of IM penicillin G (preferred) or oral penicillin V or amoxicillin for 10 days
   o For penicillin allergic patients, use cefazolin, clindamycin or a macrolide (azithromycin)
4. Anti-inflammatory drugs:
   ➢ Salicylates: →
   - 50-70 mg/k/day (maximum 6 grams) for 3-5 days,
   - Then 50 mg/k/day for 3 weeks,
   - Then 25 mg/kg/day for 2-4 weeks
   o is indicated for:
   ▪ Arthritis
   ▪ Mild to moderate carditis (no heart failure)
   ▪ On withdrawal of corticosteroids.
   Side effects of aspirin are gastritis, salicylism, Rye syndrome, ……
   ➢ Corticosteroids: (prednisone) is indicated in:
   ▪ Moderate carditis with heart failure
   ▪ Severe carditis with or without heart failure
   ▪ Allergy or contraindication to aspirin
   Dose →Prednisone 2 mg/kg/day (maximum 60 mg) for 2-3 weeks
   Then 1 mg/kg/day for 2-3 week
   Then tapering of the dose by 5 mg/24 hr every 2-3 days with introduction of aspirin 50 mg/day for 6 weeks to avoid recurrence.
   ➢ Other lines of treatment:
   * Rheumatic chorea → Haloperidol (Safinase tab.) 0.03 mg/k/day or chlorpromazine 0.5 mg/k/day.
   * Treatment of heart failure : Oxygen, salt restricton, corticosteroid , diuretics and cautious use of Digoxin.
   * Surgical management of residual valvular lesions (Rheumatic heart disease).