Development of Epidural and Paraspinal Abscesses after Insufficient Evaluation and Treatment of Acute Pyelonephritis Caused by Staphylococcus aureus

Diagnoses of pyelonephritis caused by Staphylococcus aureus should be accompanied by investigations of concomitant bladder obstruction and metastatic infections, especially to the spine or heart. Complicated pyelonephritis due to S. aureus requires more than 2 weeks of antibiotics, which is the typically recommended treatment duration for pyelonephritis. We describe a patient who was diagnosed with complicated epidural and paraspinal abscesses after insufficient evaluation and treatment of acute pyelonephritis due to S. aureus. A 62-year-old man with type 2 diabetes was admitted with fever, increased urinary frequency, and left flank pain. He was diagnosed with acute pyelonephritis caused by S. aureus. His fever and flank pain subsided after 3 days of intravenous antibiotics. Evaluation of bladder obstruction and metastatic infection were not performed, as he declined further evaluation. The patient was discharged with oral antibiotics and was requested to attend weekly appointments but was lost to follow-up. One month later, the patient presented at the outpatient clinic with similar symptoms. Computed tomography showed recurrent pyelonephritis and a distended bladder. His flank pain persisted despite administration of an opioid agent. Therefore, magnetic resonance imaging was performed, revealing epidural and paraspinal abscesses. Ultrasound-guided aspiration of the paraspinal muscle layer was performed, and blood and percutaneous aspirated fluid cultures revealed S. aureus growth. The pattern of antimicrobial sensitivity was identical to that at his first admission. Following more than 4 weeks of antibiotics, magnetic resonance imaging showed the abscesses had decreased in size. The patient was discharged without neurologic sequelae and was provided with oral antibiotics.