Differential Diagnosis for 4-year-old Female with Positive EBV EA IgG, Elevated ALT/AST, Elevated ESR, Normal CRP, Fever for 10 Days, Oral Lesions, and Rash

• Single Most Likely Diagnosis
  • Infectious Mononucleosis (IMN): Justification - Positive EBV EA IgG suggests a current or recent EBV infection, which is consistent with IMN. Elevated liver enzymes (ALT/AST) and fever are common in IMN. Oral lesions and rash can also occur, especially if the patient is taking certain medications like ampicillin.
• Other Likely Diagnoses
  • Kawasaki Disease: Justification - Although less likely given the positive EBV serology, Kawasaki disease can present with fever, rash, oral lesions (such as strawberry tongue), and elevated inflammatory markers. The absence of significantly elevated CRP does not rule out this diagnosis.
  • Acute Viral Hepatitis: Justification - Elevated ALT/AST could indicate hepatitis. However, the presence of oral lesions and rash, along with positive EBV serology, makes this less likely but still a consideration.
• Do Not Miss Diagnoses
  • Juvenile Idiopathic Arthritis (JIA): Justification - Although less common, systemic JIA can present with fever, rash, and elevated inflammatory markers. It's crucial not to miss this diagnosis due to its potential for severe complications if left untreated.
  • Autoimmune Hepatitis: Justification - This condition can present with elevated liver enzymes and systemic symptoms like fever. It's essential to consider and rule out autoimmune hepatitis due to its treatment implications.
  • Sepsis or Bacterial Infection: Justification - Despite the normal CRP, it's crucial to consider bacterial infections or sepsis, especially with prolonged fever and systemic symptoms. These conditions require immediate attention and treatment.
• Rare Diagnoses
  • Hemophagocytic Lymphohistiocytosis (HLH): Justification - This rare condition can be triggered by viral infections, including EBV. It presents with fever, hepatosplenomegaly, and cytopenias, among other symptoms. Although rare, it's a diagnosis that should be considered due to its high mortality rate if not treated promptly.
  • Systemic Lupus Erythematosus (SLE): Justification - SLE can present with a wide range of symptoms, including fever, rash, oral lesions, and elevated liver enzymes. It's a rare diagnosis in children but should be considered in the differential due to its potential for severe complications.