Acute Rheumatic Fever: A Guide for Junior Doctors

Acute rheumatic fever (ARF) is a multisystem inflammatory disease triggered by an autoimmune response to Group A Streptococcus(GAS) infection. ARF primarily affects children and young adults in regions with limited healthcare access but can present in any setting. This blog will guide you on how to approach a patient with suspected ARF, focusing on history-taking, examination,investigations, and management.

History-Taking: Asking the Right Questions

·       Key Symptoms

·       Sore throat or fever history:

o   Have you had a sore throat or fever in the last 2-4 weeks?

o   Did you notice any difficulty swallowing or swollen glands?

·       Joint symptoms:

o   Do you have joint pain or swelling?

o   Does the pain move from one joint to another (migratory pattern)?

·       Cardiac symptoms:

o   Have you experienced chest pain, palpitations, or shortness of breath?

o   Have you noticed any fatigue, particularly with exertion?

·       Neurological symptoms:

o   Have you had uncontrollable movements, twitching, or clumsiness?

o   Any emotional lability or behavioral changes?

·       Skin or other systemic symptoms:

o   Have you noticed a rash or small, painless lumps under your skin?

Risk Factors

• Recent close contacts with individuals with sore throat.

• Living in overcrowded settings or areas with poor access to healthcare.

• Previous history of ARF or rheumatic heart disease (RHD).

Examination: What to Look For

·       General Observations

• Look for signs of malaise or fatigue.

• Check for fever (>38°C).

·       Key Systems to Examine

• Joints:

·       Inspect for redness, warmth, and swelling, particularly in large joints like knees, ankles, wrists, and elbows.

·       Assess for tenderness and reduced range of motion (migratory polyarthritis).

• Cardiac:

• Palpate for displaced apex beat or thrills (suggestive of valvular disease).

• Auscultate for murmurs:

  • Mitral regurgitation: Pansystolic murmur at the apex.

  • Aortic regurgitation: Early diastolic murmur.

• Neurological:

  • Observe for involuntary movements (chorea):

    • Irregular, jerky, and purposeless movements.

  • Test for fine motor coordination (may reveal clumsiness).

• Skin:

  • Look for:

    • Erythema marginatum: Pink, non-itchy rash with a well-defined edge and central clearing.

    • Subcutaneous nodules: Small, firm, painless lumps over bony prominences.

Investigations: Confirming the Diagnosis

·       Initial Bedside Tests

• ECG: Prolonged PR interval (heart block) or other conduction abnormalities.

·       Laboratory Tests

• Throat swab: Test for GAS using rapid antigen detection or culture.

• ASO titers or anti-DNAse B: Raised levels indicate recent GAS infection.

• Inflammatory markers:

  • Elevated CRP and ESR are typical.

• FBC: Look for anemia or leukocytosis.

Imaging

• Echocardiography: Essential to detect valvular involvement or carditis.

Diagnostic Criteria

Use the Modified Jones Criteria:

• Major criteria: Carditis, polyarthritis, chorea, erythema marginatum, subcutaneous nodules.

• Minor criteria: Fever, arthralgia, elevated inflammatory markers, prolonged PR interval.

• Diagnosis requires:

  • 2 major criteria or 1 major + 2 minor criteria, plus evidence of recent GAS infection.

Management: Comprehensive Approach

·       Acute Phase

• Eradication of GAS:

  • Benzathine penicillin G IM (single dose) or oral penicillin V.

  • Alternative: Cephalexin or azithromycin (if penicillin allergy).

• Symptomatic treatment:

  • NSAIDs (e.g., naproxen or aspirin): For arthritis and fever.

  • Corticosteroids: Consider in severe carditis.

• Cardiac support:

  • Monitor for signs of heart failure (e.g., diuretics, ACE inhibitors).

• Chorea management:

  • Haloperidol or sodium valproate if severe.

·       Secondary Prevention

• Long-term antibiotic prophylaxis to prevent recurrent GAS infections:

  • Benzathine penicillin G every 3-4 weeks or daily oral penicillin.

  • Duration depends on age and severity:

    • Without carditis: At least 5 years.

    • With carditis: At least 10 years or until 21 years of age.

    • Severe RHD: Lifelong prophylaxis.

Key Learning Points for Junior Doctors

·       Early recognition of ARF is crucial to prevent long-term complications like RHD.

·       Always ask about recent sore throat and look for systemic manifestations.

·       Use the Modified Jones Criteria to guide diagnosis.

·       Management involves treating the acute infection, addressing symptoms.