NCLEX Review Guide: Rheumatic Fever in Pediatrics

Disease Process

• Rheumatic fever is an inflammatory disease that develops as a delayed sequela to group A beta-hemolytic streptococcal (GABHS) pharyngitis, typically occurring 2-3 weeks after the infection. The disease involves an abnormal autoimmune response where antibodies produced against streptococcal antigens cross-react with human tissues, particularly affecting the heart, joints, skin, and central nervous system.
• The pathogenesis involves molecular mimicry, where similarities between streptococcal M protein and human cardiac myosin, laminin, and other proteins trigger an autoimmune response that damages host tissues.

Risk Factors

• Rheumatic fever primarily affects children between 5-15 years of age, with peak incidence at 6-12 years. Untreated or inadequately treated streptococcal pharyngitis significantly increases risk, with approximately 3% of untreated cases developing rheumatic fever.
• Other risk factors include crowded living conditions, lower socioeconomic status, genetic predisposition, and living in developing countries where the disease remains prevalent.

Jones Criteria

• The diagnosis of rheumatic fever is based on the revised Jones criteria, which consists of major and minor manifestations. Diagnosis requires evidence of preceding group A streptococcal infection plus either 2 major criteria or 1 major and 2 minor criteria.

Major Manifestations in Detail

• Carditis: Occurs in approximately 50-60% of cases and may affect all layers of the heart (endocardium, myocardium, and pericardium). The mitral valve is most commonly affected, followed by the aortic valve. Clinical findings include new murmurs (especially mitral regurgitation), cardiomegaly, pericardial friction rub, or heart failure.
• Polyarthritis: Present in about 75% of cases, characterized by migratory joint pain affecting large joints (knees, ankles, elbows, wrists) sequentially. Joints appear red, swollen, warm, and extremely painful, with symptoms typically lasting 2-3 weeks without permanent damage.
• Sydenham's chorea: Occurs in 10-15% of cases, presenting as involuntary, purposeless, rapid movements primarily affecting the face and upper extremities. May be accompanied by emotional lability and muscle weakness, with symptoms lasting 1-6 months.
• Erythema marginatum: A distinctive rash seen in less than 5% of cases, characterized by pink or red macules with clear centers and well-defined borders that spread outward. The rash is transient, non-pruritic, and typically appears on the trunk and proximal extremities.
• Subcutaneous nodules: Rare (less than 5% of cases), firm, painless nodules typically found over bony prominences, particularly the elbows, knees, and wrists. Their presence often indicates more severe carditis.

Laboratory Studies

• Evidence of preceding streptococcal infection: Includes positive throat culture for group A streptococcus (though often negative by the time rheumatic fever develops), elevated or rising antistreptolysin O (ASO) titer, anti-DNase B, or streptozyme test.
• Inflammatory markers: Elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) indicate active inflammation and are part of the minor Jones criteria.
• Complete blood count (CBC) typically shows leukocytosis and mild anemia of chronic inflammation.

Cardiac Evaluation

• Electrocardiogram (ECG): May show prolonged PR interval (first-degree heart block), which is a minor criterion. Other conduction abnormalities may also be present.
• Echocardiogram: Essential for evaluating cardiac involvement, detecting valvular regurgitation (especially mitral and aortic), and assessing ventricular function. Echocardiography can detect subclinical carditis not apparent on physical examination.
• Chest X-ray may show cardiomegaly in cases with significant carditis.

Antibiotic Therapy

• Eradication of streptococcal infection: Even if throat cultures are negative, all patients diagnosed with rheumatic fever should receive antibiotics to eradicate any remaining group A streptococci.

1. Administer penicillin as the first-line treatment: Either benzathine penicillin G as a single intramuscular injection (600,000 units for children <27 kg; 1.2 million units for children ≥27 kg) OR oral penicillin V (250 mg 2-3 times daily for 10 days).
2. For penicillin-allergic patients, use erythromycin (20-40 mg/kg/day divided into 2-4 doses for 10 days, maximum 1 g/day).
3. Begin prophylactic antibiotic therapy after completing the initial treatment course.

Anti-inflammatory Therapy

• Salicylates and NSAIDs: For patients with arthritis or mild carditis, aspirin is typically administered at anti-inflammatory doses (80-100 mg/kg/day divided into 4 doses) for 2-4 weeks, then tapered over 2-3 weeks. Alternative NSAIDs may be used but are less well-studied.
• Corticosteroids: Reserved for patients with moderate to severe carditis or carditis with heart failure. Prednisone is typically given at 1-2 mg/kg/day (maximum 60 mg/day) for 2-3 weeks, followed by a gradual taper.

Secondary Prophylaxis

• Long-term antibiotic prophylaxis: Essential to prevent recurrent streptococcal infections and additional cardiac damage. Typically involves intramuscular benzathine penicillin G every 3-4 weeks or daily oral penicillin V or sulfadiazine.
• The duration of prophylaxis depends on the presence and severity of carditis: minimum of 5 years or until age 21 for patients without carditis; minimum of 10 years or until age 21 (whichever is longer) for those with carditis but no residual heart disease; lifelong for those with severe valvular disease.

Acute Care Nursing Interventions

• Monitoring: Carefully assess vital signs, particularly heart rate and rhythm, respiratory status, and signs of heart failure (increased work of breathing, peripheral edema, decreased urine output). Auscultate heart sounds regularly to detect new or changing murmurs.
• Pain management: Administer anti-inflammatory medications as prescribed and assess their effectiveness. Implement non-pharmacological pain management strategies such as proper positioning and application of warm compresses to affected joints.
• Activity modifications: Enforce bed rest during the acute inflammatory phase, especially for patients with carditis. Gradually increase activity as symptoms resolve, following healthcare provider recommendations.

Patient & Family Education

• Medication adherence: Emphasize the critical importance of completing the full course of antibiotics and adhering to long-term prophylactic regimens. Explain that even when symptoms resolve, continued medication is essential to prevent recurrence and cardiac damage.
• Recognition of streptococcal infections: Teach families to recognize symptoms of strep throat (sore throat, fever, headache, abdominal pain, absence of cough) and seek prompt medical attention.
• Follow-up care: Stress the importance of regular cardiology follow-up, even for patients without evident cardiac involvement, as valve damage can develop or progress over time.

Rheumatic Heart Disease

• Valvular damage: The most significant long-term complication is permanent damage to heart valves, known as rheumatic heart disease (RHD). The mitral valve is most commonly affected, followed by the aortic valve. Damage typically manifests as stenosis, regurgitation, or both.
• Progression: Valve damage may progress even years after the acute episode, particularly with recurrent episodes of rheumatic fever. Severe valvular disease may eventually lead to heart failure, atrial fibrillation, and increased risk of endocarditis.

Other Complications

• Sydenham's chorea: Though typically self-limited, chorea may persist for months and cause significant functional impairment and psychological distress. In rare cases, it can become chronic or recurrent.
• Psychological impact: The chronic nature of the disease, activity restrictions, and long-term medication requirements can lead to depression, anxiety, and reduced quality of life, particularly in adolescents.

• Rheumatic fever is an inflammatory sequela to group A streptococcal pharyngitis, resulting from an abnormal immune response that causes damage to the heart, joints, and other tissues.
• Diagnosis is based on the revised Jones criteria, requiring evidence of preceding streptococcal infection plus either 2 major criteria or 1 major and 2 minor criteria.
• Major manifestations include carditis, polyarthritis, chorea, erythema marginatum, and subcutaneous nodules, with carditis being the most serious due to potential long-term valve damage.
• Treatment includes antibiotics to eradicate streptococcal infection, anti-inflammatory medications to manage symptoms, and long-term prophylactic antibiotics to prevent recurrence.
• Rheumatic heart disease is the most significant complication, potentially leading to lifelong cardiac problems requiring ongoing medical management and possibly valve surgery.

Memory Aids

Common Pitfalls

Quick Check Questions