Differential Diagnosis for a 19-year-old girl with 3 weeks of fever, increased ASO titre, and throat swab showing gram-positive cocci

• Single most likely diagnosis:
  • Acute Rheumatic Fever (ARF) - Justification: The increased Anti-Streptolysin O (ASO) titre is a strong indicator of a recent streptococcal infection, which is a precursor to ARF. The symptoms of fever, general body tiredness, and the presence of gram-positive cocci on the throat swab further support this diagnosis.
• Other Likely diagnoses:
  • Streptococcal Pharyngitis - Justification: The presence of gram-positive cocci on the throat swab and the symptoms of fever and general body tiredness could indicate an ongoing streptococcal infection.
  • Infective Endocarditis - Justification: Although less common, the prolonged fever and the presence of gram-positive cocci could suggest infective endocarditis, especially if there are underlying heart conditions.
• Do Not Miss diagnoses:
  • Septicemia - Justification: Bacteremia or septicemia due to streptococcal infection could present with similar symptoms and is a potentially life-threatening condition if not promptly treated.
  • Meningitis - Justification: Though less likely, meningitis caused by streptococcal infection is a critical condition that requires immediate diagnosis and treatment to prevent severe complications or death.
• Rare diagnoses:
  • Post-Streptococcal Glomerulonephritis (PSGN) - Justification: This is a rare complication of streptococcal infection, characterized by kidney inflammation, and could present with non-specific symptoms such as fever and tiredness in the early stages.
  • Streptococcal Toxic Shock Syndrome (STSS) - Justification: A severe and rare condition caused by streptococcal toxins, presenting with high fever, severe pain, and potentially life-threatening shock.

Treatment Approach

Treatment should be guided by the confirmed diagnosis but generally includes:

• Antibiotics: For streptococcal infections, penicillin or amoxicillin is typically the first line of treatment.
• Supportive Care: Rest, hydration, and pain management are crucial for recovery.
• Specific Treatments:
  • For ARF, aspirin or other anti-inflammatory medications may be used to reduce inflammation, and prophylactic antibiotics may be recommended to prevent recurrent infections.
  • For infective endocarditis, prolonged antibiotic therapy is necessary, and in some cases, surgical intervention may be required.
  • For septicemia or meningitis, aggressive antibiotic therapy and supportive care in an intensive care setting may be necessary.

It's essential to consult a healthcare professional for a definitive diagnosis and treatment plan tailored to the individual's condition.