A 5-year-old girl without past history of UTI is in the hospital on antibiotics for E coli pyelonephritis. She is still febrile after 4 days of appropriate antibiotics. A renal ultrasound revealed no abscess, but a focal enlargement of one of the lobes of the right kidney. CT scan of the abdomen reveals a wedge-shaped area in the right kidney distinct from the normal tissue with minimal contrast enhancement. Appropriate management of this patient includes which of the following interventions?

The patient in the question has acute lobar nephronia, which is in the middle of the spectrum between pyelonephritis and renal abscess. Patients have prolonged fever curves despite appropriate antibiotics. A CT scan is most useful in diagnosing nephronia, but a renal ultrasound can identify the process as well. Treatment is prolonged IV and then PO antibiotics. Shorter courses like the typical treatment for pyelonephritis can lead to recurrence and renal abscess. Surgery and biopsy are not necessary, and a DMSA scan, while identifying alterations in flow consistent with pyelonephritis, would not add to the patient's care. (Note that there is an error in the McMillan text referenced above, referring to labor nephronia in both the figure accompanying the text as well as the index)]