Rheumatic fever

• Rheumatic fever:

  • Systemic inflammatory disorder
  • Complication of infection with group A Streptococcus
  • Is not contagious
• Pathophysiology:

  • Caused by group A beta-haemolytic streptococcal bacteria, typically streptococcus pyogenes causing tonsillitis
  • Can also present as an infection of the skin e.g. cellulitis
  • Hypersensitivity reaction against the bacteria - type 2 reaction
  • Similarities in the molecular makeup of the cell walls of the streptococcal bacteria and human heart valve tissue may result in the body's antibodies attaching the host instead of the pathogen
• This results in a type 2 hypersensitivity reaction, where the immune system begins attacking cells throughout the body. This process is usually delayed 2 – 4 weeks after the initial infection.
• The typical presentation of rheumatic fever occurs 2 – 4 weeks following a streptococcal infection, such as tonsillitis. Symptoms affect multiple systems, causing:

  • Fever
  • Joint pain
  • Rash
  • Shortness of breath
  • Chorea
  • Nodules
• Joint involvement:

  • Polyarthritis is the most common symptom
  • Multiple joints are affected, predominantly larger joints
  • Joints become red, hot and swollen
  • Each joint is usually affected for less than a week
  • The arthritis is described as a "flitting" arthritis because it migrates to other joints
• Carditis (50% of patients):

  • Every layer of the heart can be affected = pancarditis
  • Damage to the endocardium leads to endocarditis - valvular dysfunction, patients may present with significant murmurs
  • Myocardial inflammation (myocarditis) may result in heart failure and conduction defects - both potentially fatal complications
  • Pericarditis - benign pericardial rub, may lead to pericardial effusions or cardiac tamponade
  • Mitral valve is most commonly affected - valve incompetence more common in acute phase, stenosis may occur due to chronic disease many years later
• Sydenham's chorea:

  • Rare, late-presenting sign of rheumatic fever
  • Appears around 2-6 months after initial strep infection
  • Involuntary, semi-purposeful movements of the body which may be unilateral or bilateral
  • Occasionally the chorea is preceded by emotional lability or behaviour which is out of character for the patient
• Erythema marginatum:

  • Rash that presents early on in the disease process
  • Rare sign
  • Pink macular rash
  • Predominantly affecting the trunk and limbs while sparing the face
  • Expands outwards, leaving a pale centre
  • Described as a geographical rash - borders resemble those drawn on a map
  • Not itchy
• Subcutaneous nodules:

  • Hard, mobile, pea-sized nodules
  • Typically found on the extensor surfaces or the spin
  • Often painless and normally disappear within 1 month
  • Rare finding
  • Usually only seen when severe carditis is present
• Investigations that can help support the diagnosis include:

  • Throat swab for bacterial culture
  • ASO antibody titres
  • Echocardiogram, ECG and chest xray can assess the heart involvement
• Anti-streptococcal antibodies (ASO) are antibodies against streptococcus. They indicate a recent streptococcus infection and can be helpful in supporting a diagnosis of rheumatic fever. After an acute infection the levels usually:

  • Rise over 2 – 4 weeks
  • Peak around 3 – 6 weeks
  • Gradually falls over 3 – 12 months
• A diagnosis of rheumatic fever can be made when there is evidence of recent streptococcal infection, plus:

  • Two major criteria OR
  • One major criteria plus two minor criteria
• The mnemonic for the Jones criteria is JONES – FEAR.
• Major Criteria:

  • J – Joint arthritis
  • O – Organ inflammation, such as carditis
  • N – Nodules
  • E – Erythema marginatum rash
  • S – Sydenham chorea
•  Minor Criteria:

  • Fever
  • ECG Changes (prolonged PR interval) without carditis
  • Arthralgia without arthritis
  • Raised inflammatory markers (CRP and ESR)
• Treatment of streptococcal infections with antibiotics helps prevent the development of rheumatic fever. Tonsillitis caused by streptococcus should be treated with phenoxymethylpenicillin (penicillin V) for 10 days.
• Patients with clinical features of rheumatic fever should be referred immediately for specialist management. Management involves medications and follow up:

  • NSAIDs (e.g. ibuprofen) are helpful for treating joint pain
  • Aspirin and steroids are used to treat carditis
  • Prophylactic antibiotics (oral or intramuscular penicillin) are used to prevent further streptococcal infections and recurrence of the rheumatic fever. These are continued into adulthood.
  • Monitoring and management of complications
• Penicillin is the antibiotic of choice to kill any remaining streptococcal bacteria. A single stat dose of intravenous benzylpenicillin is administered initially, followed by oral penicillin V (phenoxymethylpenicillin) for at least 10 day
• Prophylaxis:

  • Benzathine penicillin G - given every 4 weeks as an IM injection
  • How long prophylaxis treatment should be given depends on the severity of the disease - usually continued for life where there is both carditis and persistent valvular disease
• Cardiac complications may be diverse and can include:

  • Carditis (e.g. infective endocarditis)
  • Heart failure
  • Pericardial effusions
  • Valvular disease (especially the mitral valve)
  • Atrial fibrillation (from severe untreated mitral stenosis)
  • Pulmonary hypertension
  • Thromboembolic events, such as strokes (a consequence of atrial fibrillation)
• Most of the other features that appear during acute attacks of rheumatic fever, such as joint swelling and skin changes, are thought to be transient, leaving no permanent damage after the flare-up has resolved