Differential Diagnosis
- Single most likely diagnosis
- Acute post-streptococcal glomerulonephritis (APSGN): This condition is suggested by the recent history of a skin infection treated with antibiotics, which could have been caused by a streptococcal infection. The patient's presentation with hypertension, periorbital edema, and trace pitting edema, along with laboratory findings of hematuria (20-30 RBCs/hpf), proteinuria (2+), and elevated creatinine (2.2 mg/dL), supports this diagnosis.
- Other Likely diagnoses
- Acute kidney injury (AKI) due to other causes: The patient's elevated creatinine and blood urea nitrogen (BUN) levels indicate impaired renal function, which could be due to various causes such as medication-induced nephrotoxicity (e.g., from cephalexin, although less common), dehydration, or other renal pathologies.
- Nephrotic syndrome: Although less likely given the presence of hematuria, nephrotic syndrome could be considered due to the patient's proteinuria and edema. However, the absence of significant hypoalbuminemia and the presence of hematuria make APSGN more likely.
- 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, hemolytic anemia, and thrombocytopenia. Although the patient's platelet count is normal, and there's no mention of diarrhea or a typical HUS-associated infection, it's crucial to consider due to its severity and potential for rapid progression.
- Vasculitis (e.g., Henoch-Schönlein purpura): Although the patient does not have the classic purpuric rash, vasculitis can present with renal involvement, hypertension, and edema. Missing this diagnosis could lead to delayed treatment and potential long-term renal damage.
- Rare diagnoses
- Membranoproliferative glomerulonephritis: A less common cause of nephritic syndrome, which could present with hematuria, proteinuria, and renal impairment. It is often associated with chronic infections, autoimmune diseases, or complement pathway abnormalities.
- Alport syndrome: A genetic disorder affecting the type IV collagen in the glomerular basement membrane, leading to chronic kidney disease, hearing loss, and eye abnormalities. Although rare and less likely given the acute presentation, it should be considered in the differential diagnosis of a child with hematuria and renal impairment.