Rheumatic Fever

Key Points

• Rheumatic fever is an autoimmune inflammatory response that occurs 2-4 weeks after untreated or inadequately treated GABHS pharyngitis.
• Carditis (inflammation of the heart) is the most serious manifestation, causing permanent valvular damage (rheumatic heart disease), particularly mitral and aortic valves.
• Diagnosis uses the modified Jones criteria: major criteria include carditis, polyarthritis, chorea, erythema marginatum, and subcutaneous nodules.
• Prevention focuses on prompt antibiotic treatment of strep pharyngitis with penicillin; secondary prophylaxis prevents recurrences.

Pathophysiology

Rheumatic fever is caused by a delayed autoimmune response following GABHS pharyngitis. Antibodies produced against streptococcal M-protein cross-react with similar antigens found in human cardiac tissue, joint synovium, brain, and skin through a process called molecular mimicry. This autoimmune cross-reactivity triggers a systemic inflammatory response that can affect the heart, joints, central nervous system, and skin. Carditis involves inflammation of all three cardiac layers (pancarditis — endocardium, myocardium, pericardium). Repeated episodes cause progressive valvular fibrosis and scarring, most commonly affecting the mitral valve, leading to chronic rheumatic heart disease with stenosis and/or regurgitation.

Clinical Manifestations

Major Criteria (Modified Jones Criteria)

• Carditis: New murmur (especially mitral regurgitation), tachycardia, cardiomegaly, heart failure.
• Migratory polyarthritis: Large joint inflammation that migrates from joint to joint (most common manifestation).
• Sydenham chorea: Involuntary purposeless movements, emotional lability; occurs weeks to months after infection.
• Erythema marginatum: Non-pruritic, pink-red macular rash with pale centers on the trunk and proximal extremities.
• Subcutaneous nodules: Small, firm, painless nodules over bony prominences and tendons.

Minor Criteria

• Fever, arthralgia (without arthritis), elevated ESR or CRP, prolonged PR interval on ECG.

Nursing Assessment

NCLEX Focus

Remember the major Jones criteria mnemonic: J-O-N-E-S = Joint involvement (polyarthritis), O (carditis — think “O” for heart), Nodules (subcutaneous), Erythema marginatum, Sydenham chorea. Prompt treatment of strep pharyngitis prevents rheumatic fever.

• Auscultate heart sounds for new murmurs, particularly mitral regurgitation.
• Assess joints for swelling, redness, warmth, and migratory pattern.
• Observe for involuntary movements (chorea) and emotional lability.
• Inspect skin for erythema marginatum rash and palpate for subcutaneous nodules.
• Monitor vital signs for fever and tachycardia.
• Review laboratory results: elevated ESR and CRP, positive ASO (antistreptolysin O) titer, throat culture.
• Obtain ECG to assess for prolonged PR interval.

Nursing Interventions

• Administer prescribed antibiotics: penicillin V (oral) or benzathine penicillin G (IM injection) to eradicate residual GABHS.
• Manage acute inflammation with prescribed anti-inflammatory agents: aspirin for joint pain and fever, corticosteroids for severe carditis.
• Maintain bed rest during the acute phase, especially if carditis is present; gradually increase activity as inflammation resolves.
• Implement long-term secondary prophylaxis: monthly benzathine penicillin G injections to prevent recurrent streptococcal infection and further cardiac damage.
• Monitor for signs of heart failure: dyspnea, edema, weight gain, jugular venous distension.
• Educate the family about the importance of completing the full antibiotic course for any strep throat infection.
• Teach the child and family about lifelong follow-up for cardiac monitoring if valvular damage is present.
• Provide emotional support for the child with chorea; ensure a safe environment to prevent injury from involuntary movements.

Prevention Is Key

Rheumatic fever is entirely preventable. Prompt identification and antibiotic treatment of GABHS pharyngitis within 9 days of symptom onset prevents the autoimmune response.

Related Concepts

• pharyngitis-tonsillitis-and-adenoiditis — GABHS pharyngitis as the triggering infection.
• congenital-heart-defects-acyanotic-and-cyanotic-patterns — Acquired vs. congenital valvular disease comparison.
• heart-failure — Complication of chronic rheumatic heart disease.
• infection-control — Prevention through early treatment of streptococcal infections.
• Autoimmune Disorders — Molecular mimicry as pathophysiologic mechanism.

Self-Check

1. What are the five major criteria in the modified Jones criteria for rheumatic fever?
2. Which heart valve is most commonly affected in rheumatic heart disease?
3. What is the primary prevention strategy for rheumatic fever?