Differential Diagnosis for a 5-year-old Girl with Facial Swelling, Fatigue, and Dark Urine

Single Most Likely Diagnosis

• Acute Poststreptococcal Glomerulonephritis (APSGN): This condition is a common cause of acute nephritic syndrome in children, often following a streptococcal infection like pharyngitis. The recent sore throat, facial swelling (edema), fatigue, and dark urine (indicative of hematuria) are classic presentations of APSGN.

Other Likely Diagnoses

• Nephrotic Syndrome: Although less common than APSGN in the context of a recent infection, nephrotic syndrome can present with edema, fatigue, and changes in urine color due to proteinuria. However, the recent history of sore throat and the presence of hematuria might lean more towards APSGN.
• Urinary Tract Infection (UTI): While UTIs are common in children and can cause changes in urine appearance, the combination of facial swelling, recent sore throat, and the specific mention of dark urine suggests a more systemic or glomerular issue rather than a lower urinary tract infection.

Do Not Miss Diagnoses

• Rapidly Progressive Glomerulonephritis (RPGN): Although less common, RPGN is a serious condition that can present similarly to APSGN but with a more aggressive course, leading to rapid loss of renal function. The absence of fever does not rule out RPGN, and missing this diagnosis could have severe consequences.
• Henoch-Schönlein Purpura (HSP): HSP can cause renal involvement, presenting with hematuria and proteinuria, along with the characteristic purpura, abdominal pain, and arthritis. While the absence of purpura makes this less likely, HSP is a diagnosis that should not be missed due to its potential for renal and other systemic complications.

Rare Diagnoses

• Alport Syndrome: A genetic disorder affecting the type IV collagen in the glomerular basement membrane, leading to hematuria, proteinuria, and progressive renal failure. It's less likely given the acute presentation and recent infection but could be considered in the differential for chronic or familial cases.
• Membranoproliferative Glomerulonephritis: A rare cause of nephritic syndrome, characterized by changes in the glomeruli that can lead to hematuria and proteinuria. It's less common in children and not typically associated with a recent streptococcal infection, making it a less likely but possible rare diagnosis.