What is the management approach for a 13-year-old male patient presenting with rash, bone pain, and swelling 2 weeks after streptococcal (strep) pharyngitis?

Management of Post-Streptococcal Complications in a 13-Year-Old

This patient requires immediate evaluation for acute rheumatic fever (ARF), which presents with rash, bone/joint pain, and swelling 2-3 weeks after streptococcal pharyngitis. 1

Immediate Diagnostic Workup

Confirm the diagnosis using the Jones Criteria, which requires evidence of preceding GAS infection plus major and/or minor manifestations: 2

Evidence of Preceding GAS Infection

• Throat culture or rapid antigen detection test (RADT) for current GAS infection 3
• Anti-streptolysin O (ASO) or anti-DNase B titers to document recent streptococcal exposure 1
• Note: The 2-week timeframe post-pharyngitis is classic for ARF development 1, 4

Major Manifestations to Assess

• Arthritis: Migratory polyarthritis affecting large joints (knees, ankles, elbows, wrists) - likely present given "bone pain and swelling" 1, 5
• Carditis: Auscultate for new murmurs, obtain ECG and echocardiogram to evaluate for valvular involvement 2
• Erythema marginatum: Examine for this characteristic rash with pink-red macules with pale centers on trunk/proximal extremities 1
• Subcutaneous nodules: Palpate for firm, painless nodules over bony prominences 1
• Sydenham chorea: Assess for involuntary movements (though typically presents later) 2

Minor Manifestations

• Fever, elevated acute phase reactants (ESR, CRP), prolonged PR interval on ECG 1, 2

Acute Treatment Protocol

Anti-Inflammatory Therapy

Initiate aspirin 80-100 mg/kg/day divided into 4-6 doses for arthritis control, continuing for 2 weeks after clinical improvement, then taper over 2-4 weeks (total 12 weeks of therapy): 2

• For severe carditis with cardiomegaly or heart failure, add prednisone 2 mg/kg/day (maximum 60-80 mg/day) for 2-3 weeks, then taper 2
• Monitor for aspirin toxicity (tinnitus, hyperventilation) 2

Streptococcal Eradication

Administer benzathine penicillin G 1.2 million units intramuscularly as a single dose (patient weighs ≥27 kg at age 13): 3, 6, 2

• Alternative: Penicillin V 500 mg orally 2-3 times daily for 10 days 3, 6
• For penicillin allergy: Azithromycin 12 mg/kg once daily for 5 days (maximum 500 mg) 2
• This eradicates the organism even though treatment within 9 days prevents ARF; eradication is still necessary 3

Secondary Prophylaxis - Critical for This Patient

Begin lifelong secondary prophylaxis immediately after acute treatment, as this patient is now at very high risk for ARF recurrence with subsequent GAS infections: 6, 2

Prophylaxis Regimen

• Benzathine penicillin G 1.2 million units intramuscularly every 3-4 weeks (preferred due to superior adherence) 6, 2
• Alternative: Penicillin V 250 mg orally twice daily 6
• For penicillin allergy: Sulfadiazine 1 gram daily or erythromycin 250 mg twice daily 6

Duration of Prophylaxis

• Minimum 5 years after last ARF episode OR until age 21 (whichever is longer) for ARF without carditis 6, 2
• Minimum 10 years after last episode OR until age 25 for ARF with carditis but no residual heart disease 6
• Lifelong prophylaxis if persistent valvular disease develops 6, 2

Critical Management Pitfalls to Avoid

• Do not confuse ARF with post-streptococcal reactive arthritis (PSRA): PSRA has shorter latency (days vs. 2-3 weeks), non-migratory arthritis, poor response to aspirin, and no cardiac involvement - but ARF requires secondary prophylaxis while PSRA does not 5
• Do not delay echocardiography: Subclinical carditis may be present even without audible murmur, and cardiac involvement determines prophylaxis duration 2
• Do not use aspirin without confirming diagnosis: Aspirin dramatically improves ARF arthritis within 24-48 hours, which can mask the diagnosis if given prematurely 2
• Do not assume post-treatment cultures are needed: Routine follow-up throat cultures after completing acute treatment are not recommended 3, 7

Long-Term Monitoring

• Serial echocardiograms to monitor for development or progression of valvular disease 2
• Ensure strict adherence to secondary prophylaxis, as recurrent ARF episodes cause cumulative cardiac damage 6
• Educate patient and family that ARF is preventable with prophylaxis, and that rheumatic heart disease remains a leading cause of cardiovascular death in the first five decades of life globally 1