Differential Diagnosis for a 9-year-old boy with lethargy, headache, nausea, and decreased urine output
- Single most likely diagnosis
- Post-streptococcal glomerulonephritis (PSGN): This condition is a leading cause of acute nephritic syndrome in children, often following a streptococcal infection like the sore throat the patient had 2 weeks ago. The presentation of hypertension, edema, hematuria, and proteinuria supports this diagnosis.
- Other Likely diagnoses
- Acute glomerulonephritis (other causes): Other infections or conditions could cause acute glomerulonephritis, presenting similarly to PSGN but without a clear link to a streptococcal infection.
- Nephrotic syndrome: Although less likely given the presence of hematuria and hypertension, nephrotic syndrome could present with edema and proteinuria, but it typically has more significant protein loss and less hematuria.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed)
- Hemolytic uremic syndrome (HUS): This condition, often associated with E. coli infections, can cause acute kidney injury, hypertension, and edema, but it typically presents with more pronounced hemolytic anemia.
- Vasculitis (e.g., Henoch-Schönlein purpura): Although the patient does not have a rash, abdominal pain, or joint pain, these conditions can sometimes present atypically and would be critical to diagnose due to their potential for severe complications.
- Severe urinary tract infection or pyelonephritis: While the patient does not report dysuria, a severe infection could cause systemic symptoms and acute kidney injury.
- Rare diagnoses
- Alport syndrome: A genetic disorder affecting the type IV collagen in the kidneys, ears, and eyes, which could present with hematuria and proteinuria, but it is less likely given the acute presentation.
- Membranoproliferative glomerulonephritis: A rare cause of glomerulonephritis that could present with similar symptoms but is less common in children.
- Goodpasture syndrome: An autoimmune disease causing glomerulonephritis and pulmonary hemorrhage, which is rare in children and would typically present with more respiratory symptoms.