Differential Diagnosis for Rheumatic Fever

When considering a diagnosis of rheumatic fever based on history and examination, several other conditions must be taken into account due to overlapping symptoms. The differential diagnoses can be categorized as follows:

• Single Most Likely Diagnosis

  • Acute Rheumatic Fever: This is the most likely diagnosis when the patient presents with a recent history of streptococcal pharyngitis followed by symptoms such as migratory polyarthritis, carditis, chorea, erythema marginatum, or subcutaneous nodules. The diagnosis is primarily clinical, supported by the Jones criteria.

• Other Likely Diagnoses

  • Juvenile Idiopathic Arthritis (JIA): Presents with joint inflammation and can mimic the arthritis seen in rheumatic fever. However, JIA typically does not have the migratory pattern and is not preceded by a streptococcal infection.
  • Post-streptococcal Reactive Arthritis (PSRA): Similar to rheumatic fever, it follows a streptococcal infection but typically does not fulfill the full Jones criteria for rheumatic fever and lacks the cardiac involvement.
  • Infective Endocarditis: Can present with fever, heart murmur, and embolic phenomena, overlapping with the carditis of rheumatic fever. The presence of a pre-existing heart condition and the nature of the murmur can help differentiate.

• Do Not Miss Diagnoses

  • Endocarditis: Although mentioned under other likely diagnoses, it's crucial to emphasize that missing endocarditis can be fatal. The diagnosis should be considered in anyone with a new heart murmur, especially if there's a history of heart disease or intravenous drug use.
  • Lyme Disease: Caused by Borrelia burgdorferi, it can present with arthritis, carditis, and neurological manifestations, mimicking some aspects of rheumatic fever. The presence of a rash (erythema migrans) and exposure history can help differentiate.
  • Kawasaki Disease: An acute febrile illness of childhood that can lead to coronary artery aneurysms if not treated promptly. It presents with fever, rash, conjunctivitis, and changes to the lips and oral cavity, which are distinct from rheumatic fever.

• Rare Diagnoses

  • Sydenham's Chorea without Other Manifestations of Rheumatic Fever: Can occur months after the initial streptococcal infection and may present with neurological symptoms such as chorea without other signs of rheumatic fever.
  • Whipple's Disease: A rare, systemic bacterial infection that can cause arthritis, fever, and cardiac symptoms, although it is much less common and typically presents with gastrointestinal symptoms.
  • Autoimmune Disorders (e.g., Systemic Lupus Erythematosus): Can present with a wide range of symptoms including arthritis, carditis, and neurological manifestations, but the presence of specific autoantibodies and other systemic features helps differentiate these conditions from rheumatic fever.