I have fever possibly due to rheumatic fever; what immediate evaluation and management is recommended?

Immediate Evaluation and Management of Suspected Acute Rheumatic Fever

If you suspect acute rheumatic fever based on fever and clinical presentation, immediately confirm or exclude group A streptococcal infection through throat culture or rapid antigen testing, apply the revised Jones criteria for diagnosis, initiate a full 10-day course of penicillin to eradicate streptococci regardless of culture results, and begin continuous secondary prophylaxis with intramuscular benzathine penicillin G to prevent recurrence. 1, 2

Diagnostic Evaluation

Confirm Group A Streptococcal Infection

• Document recent streptococcal infection through throat culture, rapid antigen detection test, or anti-streptolysin O/anti-DNase B titers, as diagnosis of acute rheumatic fever requires evidence of preceding group A streptococcal pharyngitis 1, 3
• Without documentation of antecedent group A streptococcal infection, the diagnosis is much less likely except in rare scenarios 3

Apply the Revised Jones Criteria

• Diagnosis requires: Evidence of group A streptococcal infection PLUS either 2 major manifestations OR 1 major plus 2 minor manifestations 1
• Major manifestations include: Carditis (clinical or subclinical by echocardiography), polyarthritis or monoarthritis (in high-risk populations), chorea, erythema marginatum, and subcutaneous nodules 1
• Minor manifestations include: Fever (≥38.5°C in low-risk or ≥37.5°C in high-risk populations), polyarthralgia (or monoarthralgia in high-risk populations), elevated acute phase reactants (ESR ≥60 mm/hr or CRP ≥3.0 mg/dL), and prolonged PR interval on ECG 1

Essential Cardiac Assessment

• Obtain echocardiography immediately to detect subclinical carditis, as Doppler echocardiography can identify valvular regurgitation not apparent on clinical examination and is now incorporated into the revised Jones criteria 1
• Look specifically for mitral regurgitation (most common), aortic regurgitation, and evidence of valvulitis with abnormal leaflet coaptation 1

Immediate Antibiotic Management

Primary Treatment to Eradicate Streptococci

• Administer a full 10-day course of penicillin even if throat culture is negative at the time of acute rheumatic fever diagnosis 1, 2
• Oral penicillin V: 250 mg twice daily for 10 days (for children <27 kg) or 500 mg 2-3 times daily for 10 days (for children ≥27 kg, adolescents, and adults) 2
• Intramuscular benzathine penicillin G: Single injection of 600,000 units (<27 kg) or 1,200,000 units (≥27 kg) 2
• Strongly consider intramuscular route for patients unlikely to complete oral therapy, those with personal or family history of rheumatic fever/rheumatic heart disease, or those with environmental risk factors 2

Initiate Secondary Prophylaxis Immediately

• Begin continuous antimicrobial prophylaxis as soon as acute rheumatic fever is diagnosed to prevent recurrent attacks, which cause progressively worse cardiac damage 1, 2
• Benzathine penicillin G 1.2 million units intramuscularly every 4 weeks is the gold standard, providing approximately 10 times greater protection than oral antibiotics (0.1% versus 1% recurrence rate; RR 0.07,95% CI 0.02-0.26) 2, 4
• In high-risk populations or if recurrence occurs despite adherence, administer benzathine penicillin G every 3 weeks instead of every 4 weeks 1, 2

Symptomatic Treatment

Anti-Inflammatory Therapy

• High-dose aspirin (acetylsalicylic acid) 75-100 mg/kg/day is effective for controlling inflammatory manifestations of arthritis and mild carditis, with arthritis typically resolving within days of initiating therapy 2
• Continue aspirin for 4-6 weeks for symptomatic relief 2

Duration of Secondary Prophylaxis

The duration depends critically on whether cardiac involvement occurred and whether residual valvular disease persists: 1, 2

• Rheumatic fever WITH carditis AND persistent valvular disease: 10 years or until age 40 (whichever is longer), sometimes lifelong prophylaxis 1
• Rheumatic fever WITH carditis but NO residual valvular disease: 10 years or until age 21 (whichever is longer) 1
• Rheumatic fever WITHOUT carditis: 5 years or until age 21 (whichever is longer) 1

Critical Pitfalls to Avoid

• Never rely on a 10-day oral penicillin course alone as secondary prophylaxis—this is primary treatment only; continuous prophylaxis is required because recurrent acute rheumatic fever can occur even when symptomatic infections are treated optimally, and many triggering infections are asymptomatic 2
• Do not delay treatment while awaiting confirmatory testing—if clinical suspicion is high, begin therapy immediately 1
• Avoid broad-spectrum antibiotics when narrow-spectrum penicillin is appropriate, as this is more expensive and selects for resistant flora 2
• Remember that group A streptococcal infection does not need to be symptomatic to trigger recurrence, emphasizing the critical importance of continuous prophylaxis rather than episodic treatment 1, 2
• Patients with early or mild rheumatic heart disease have the greatest capacity to benefit from intramuscular antibiotic prophylaxis (8.1% recurrence without prophylaxis versus 0.7% with prophylaxis; RR 0.09,95% CI 0.03-0.29) 4

Special Considerations for Recurrent Episodes

• In patients with reliable past history of acute rheumatic fever or established rheumatic heart disease and documented group A streptococcal infection, 2 major OR 1 major and 2 minor OR 3 minor manifestations may be sufficient for presumptive diagnosis of recurrence 1
• When only minor manifestations are present, exclude other more likely causes before diagnosing acute rheumatic fever recurrence 1
• If genuine diagnostic uncertainty exists, consider offering 12 months of secondary prophylaxis followed by reevaluation including careful history, physical examination, and repeat echocardiogram 1