Rheumatic Fever

Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management | Patient Advice

Definition

Rheumatic Fever is an inflammatory disease that occurs as a delayed complication of untreated or poorly treated streptococcal throat infection (Group A Streptococcus). It primarily affects the heart, joints, skin, and central nervous system.

Aetiology

Rheumatic fever results from an abnormal immune response to Group A Streptococcus (GAS) infection.

• Preceding Infection: Typically a streptococcal pharyngitis or tonsillitis.
• Genetic Susceptibility: Certain HLA subtypes predispose individuals to the disease.
• Environmental Factors: Overcrowded living conditions increase the risk of GAS transmission.

Pathophysiology

Rheumatic fever occurs due to molecular mimicry and an exaggerated immune response:

• Molecular Mimicry: Antibodies against streptococcal M protein cross-react with human tissues, particularly in the heart, joints, and skin.
• Inflammatory Response: Activation of T-cells and cytokines leads to tissue damage.
• Cardiac Involvement: Leads to inflammation of the heart valves (rheumatic carditis), causing chronic damage.

Risk Factors

Risk factors include:

• History of untreated or recurrent streptococcal infections.
• Living in overcrowded or unsanitary conditions.
• Genetic predisposition (specific HLA subtypes).
• Age (common in children aged 5–15 years).

Signs and Symptoms

Symptoms vary depending on the affected organ systems:

• Fever: Common and non-specific.
• Polyarthritis: Pain and swelling in multiple large joints, migrating from one joint to another.
• Carditis: Inflammation of the heart valves, myocardium, or pericardium, leading to murmurs or heart failure.
• Erythema Marginatum: A characteristic rash with pink, ring-shaped lesions on the trunk or limbs.
• Chorea: Jerky, involuntary movements due to central nervous system involvement.
• Subcutaneous Nodules: Painless lumps under the skin, often over bony prominences.

Investigations

Key investigations and common positive findings include:

• Throat Swab: Positive for Group A Streptococcus in recent infections.
• Antistreptolysin O (ASO) Titre: Elevated, indicating a recent streptococcal infection.
• C-reactive Protein (CRP) and Erythrocyte Sedimentation Rate (ESR): Raised due to systemic inflammation.
• Electrocardiogram (ECG): May show prolonged PR intervals (first-degree heart block).
• Echocardiography: Detects valvular damage or carditis.

Management

1. Primary Care Management

• Symptomatic Relief: Administer paracetamol or ibuprofen for pain and fever.
• Antibiotic Therapy: Start a single dose of benzathine penicillin G intramuscularly or oral penicillin for 10 days to eliminate streptococcal infection.
• Urgent Referral: Refer to secondary care if carditis or severe symptoms are suspected.

2. Secondary Care Management

• Anti-inflammatory Treatment: Aspirin or corticosteroids (e.g., prednisolone) for severe carditis.
• Heart Failure Management: Use diuretics and ACE inhibitors if heart failure is present.
• Monitoring and Supportive Care: Continuous cardiac monitoring in severe cases.

3. Specialist Procedures

• Valve Repair or Replacement: Indicated for severe chronic rheumatic heart disease. Performed by a cardiothoracic surgeon.

Patient Advice

Key advice includes:

• Complete the full course of antibiotics to prevent recurrence.
• Adopt good hygiene practices to reduce the spread of streptococcal infections.
• Attend regular follow-ups, especially if cardiac complications occur.
• For recurrent episodes, prophylactic antibiotics (e.g., benzathine penicillin every 3–4 weeks) may be necessary to prevent future infections.