Differential Diagnosis for Rheumatic Fever
Single Most Likely Diagnosis
- Acute Rheumatic Fever (ARF): This is the most likely diagnosis given the context of the question. ARF is an autoimmune inflammatory process that occurs after a group A beta-hemolytic streptococcal (GABHS) infection, such as strep throat. It presents with symptoms like fever, migratory polyarthritis, carditis, and sometimes neurological manifestations (Sydenham's chorea).
Other Likely Diagnoses
- Post-streptococcal Reactive Arthritis (PSRA): This condition shares a similar trigger with ARF (a recent streptococcal infection) but typically does not meet the full criteria for ARF. It presents with arthritis and sometimes urethritis or conjunctivitis, without the cardiac involvement seen in ARF.
- Infective Endocarditis: Although more commonly associated with bacterial infections, the cardiac involvement in rheumatic fever can sometimes mimic or be confused with infective endocarditis, especially if there are signs of heart valve dysfunction.
- Systemic Juvenile Idiopathic Arthritis (sJIA): This condition can present with fever, rash, and arthritis, which might be confused with the symptoms of ARF, especially in children.
Do Not Miss Diagnoses
- Endocarditis: As mentioned, this is a critical diagnosis not to miss due to its high morbidity and mortality if left untreated. The presentation can overlap with the carditis seen in ARF.
- Septic Arthritis: This condition requires urgent diagnosis and treatment to prevent joint destruction. While the arthritis in ARF is typically migratory and not septic, distinguishing between the two is crucial.
- Lupus or Other Connective Tissue Diseases: These can present with a wide range of symptoms including arthritis, fever, and sometimes cardiac involvement, making them important to consider in the differential diagnosis.
Rare Diagnoses
- Rheumatoid Arthritis (RA): Although more common in adults, juvenile idiopathic arthritis (a form of RA in children) could be considered, especially if the arthritis pattern does not fit the typical migratory pattern of ARF.
- Whipple's Disease: A rare, systemic bacterial infection that can cause arthritis, fever, and cardiac symptoms among other manifestations.
- Lyme Disease: Caused by Borrelia burgdorferi, this can lead to arthritis, carditis, and neurological symptoms, potentially mimicking some aspects of ARF, especially in endemic areas.