Differential Diagnosis

The patient presents with bilateral flank pain, hematuria, burning dysuria, fever, and nausea. The following differential diagnoses are considered:

• Single most likely diagnosis

  • Pyelonephritis: The patient's symptoms of flank pain, fever, and burning dysuria, along with the recent history of UTI treated with Augmentin, suggest a possible diagnosis of pyelonephritis. The presence of hematuria and proteinuria also supports this diagnosis.

• Other Likely diagnoses

  • Urinary Tract Infection (UTI): Although the patient was recently treated for UTI, the recurrence of symptoms suggests a possible persistent or recurrent infection.
  • Kidney Stone: The patient's flank pain and hematuria could be indicative of a kidney stone, although the CT scan did not show any evidence of hydronephrosis.

• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)

  • Sepsis: Although the patient's vital signs are stable, the presence of fever, flank pain, and recent history of UTI raises the concern for possible sepsis, particularly in a patient with a history of immunodeficiency.
  • Emphysematous Pyelonephritis: This is a rare but life-threatening condition that can occur in patients with diabetes, particularly those with poorly controlled blood sugar levels.

• Rare diagnoses

  • Renal Infarction: Although the CT scan did not show any evidence of renal infarction, this diagnosis should be considered in patients with flank pain and hematuria, particularly those with a history of hypercoagulable state.
  • Renal Vasculitis: This is a rare condition that can cause flank pain, hematuria, and proteinuria, particularly in patients with a history of autoimmune disorders.

Given the patient's symptoms and history, it would be prudent to admit the patient for further evaluation and treatment, rather than discharging them home. The presence of fever, flank pain, and hematuria, along with the recent history of UTI, suggests a possible diagnosis of pyelonephritis or sepsis, which requires prompt medical attention and hospitalization. Additionally, the patient's history of immunodeficiency increases the risk of complications and necessitates close monitoring.