Acute Rheumatic Fever

Rheumatic heart disease (RHD) is the most common acquired heart disease in children in many countries of the world, especially in developing countries.

 

The global burden of disease caused by rheumatic fever currently falls disproportionately on children living in the developing world, especially where poverty is widespread. 

World Heart Federation

Introduction

ARF is a non-infective sequelae of pharyngitis caused by group A beta-hemolytic streptococcus. Symptoms usually appear two to three weeks after the initial infection. The incidence of ARF has declined dramatically due to the introduction of antibiotics as well as a change in the M protein of the streptococci leading to alterations in rheumatogenicity. Although the initial clinical syndrome may resolve, there may be devastating cardiac consequences from valvular damage.

In the U.S., rheumatic heart disease is responsible for approximately 3500 deaths annually, compared to 233,000 deaths worldwide from rheumatic heart disease and ARF. Most deaths worldwide occur in developing countries. There is equal incidence in boys and girls, and the median age of affected patients is 10 years. While the exact mechanism of ARF is incompletely understood, molecular mimicry is thought to play an important role in the initiation of tissue injury.

Clinical features and diagnosis:

The diagnosis of ARF is made by applying the modified (1992) Jones criteria. Diagnosis requires evidence of recent streptococcal infection and 2 major criteria, or 1 major and 2 minor criteria

• Major criteria:
                    
  • Polyarthritis: Migrating arthritis that typically affects the knees, ankles, elbows and wrists. The joints are very painful and symptoms are very responsive to anti-inflammatory medicines. Arthritis is usually the first symptom in acute rheumatic fever.
                 
  • Pancarditis: All layers of cardiac tissue are affected (pericardium, epicardium, myocardium, endocardium). The patient may have a new or changing murmur, with mitral regurgitation being the most common followed by aortic insufficiency. Mitral stenosis is rarely seen in the acute case, and is indicated by late scarring and calcification of a damaged valve. Cardiomegaly is the most common radiological abnormality and ECG changes may show heart block but echocardiography is the most sensitive and shows pancarditis.

    Chorea: Also known as Syndenham’s chorea or "St. Vitus’ dance". These are abrupt, purposeless, nonrhythmic movements. Movements tend to be more marked on one side and cease during sleep. This may be the ONLY manifestation of ARF and its presence is diagnostic. Symptoms may also include emotional disturbances and inappropriate behavior. Chorea is often misdiagnosed.

  • Erythema marginatum: A non-pruritic rash that commonly affects the trunk and proximal extremities, but spares the face. The rash typically migrates from central areas to periphery, and has well-defined borders.
  • 
    https://en.wikipedia.org/wiki/Erythema_marginatum
     
  • Subcutaneous nodules: Usually located over bones or tendons, these nodules are painless and firm. The overlying skin is not inflamed and usually can be moved over the nodules.
     
• Minor criteria:
                                
  • Arthralgia
  • Fever
  • Previous ARF or rheumatic heart disease
  • Leukocytosis, Elevated ESR and CRP
  • Prolonged P-R interval on EKG
  • Evidence of recent streptococcal infection can be established by a positive throat culture, rapid strep test, or by an elevated or rising ASO titer, Anti-Deoxyribonuclease B, and Anti-Hyaluronidase. Often there is no history of a previous sore throat and the throat culture will be negative at the time of diagnosis.
     

Treatment:

1. Relieve acute symptoms with steroids and antipyretics
2. Eradicate group A beta-hemolytic streptococcus. Additionally, household contacts should have throat cultures and be treated with a full course of antibiotics if the cultures are positive.
3. Chorea - may get symptomatic relief with sodium valproate or haloperidol
4. Rash and subcutaneous nodules are self limited and do not require treatment. Antihistamines can be given for pruritis but erythema marginatum is usually non-pruritic.

5. Prophylaxis against future infection to avoid recurrent cardiac disease. Preferred antibiotic is Penicillin G intramuscularly every 4 weeks (although it may be given every 2-3 weeks in higher risk populations). The use of macrolides should be limited to patients with significant penicillin allergy due to its association with increased rates of MR and macrolide-resistant GAS.

   • No carditis - prophylaxis for 5 years or until 21 years old

   • Carditis without residual cardiac defect- prophylaxis for 10 years or until 21 years old

   • Cardiac defect -prophylaxis until 40 years old or later.

References

1. Dajani, A.S. et. al. (1992). Guidelines for the diagnosis of acute rheumatic fever: Jones criteria, 1992 update.  JAMA, 268(15), 2069-2073.
2. Mirkinson, L. (1998). The diagnosis of rheumatic fever. Pediatrics in Review, 19(9), 310-311.
3. Wilson, W. et. al. (2007). AHA guideline: prevention of infective endocarditis. Circulation, 116: 1736-1754. 
4. Logan, L.K. et. al. (2012). Macrolide treatment failure in streptococcal pharyngitis resulting in acute rheumatic fever. Pediatrics, 129(3), 798-802.
5. Zamorradi, A and Wald, E. (2006). Syndenham's chorea in western Pennsylvania. Pediatrics, (117)4, 675-679.