An uncommon cause of UTI in a pediatric patient

Introduction: Urinary tract infections (UTI) associated with renal abscesses, especially those caused by methicillin resistant Staphylococcus aureus (MRSA), are an uncommon diagnosis in the pediatric patient. Here, we present a case report outlining the clinical manifestation, management, and probable pathophysiology of a pediatric renal abscess associated with a MRSA UTI. Case description: A previously healthy 8-year-old female presented to the emergency department with a complaint of right sided flank pain. Urinalysis was significant for positive nitrites and moderate white blood cells, and was therefore sent for culture. Computed tomography of the abdomen/pelvis showed a small abscess on the left kidney, which was later confirmed on renal ultrasound. The admitting physical examination revealed a febrile and tachycardic patient with an abrasion over the right knee and negative costovertebral angle or suprapubic tenderness. The patient was started on clindamycin and ceftriaxone for empiric coverage of MRSA, anaerobes, and gram negatives. Urine culture resulted as positive for MRSA, sensitive to vancomycin. Empiric antibiotics were replaced with vancomycin based on sensitivities. Patient continued intravenous vancomycin for a total of 14 days. Prior to discharge, a follow-up renal US showed resolution of the left renal abscess. Discussion: MRSA UTIs are thought to be the result of hematogenous spread, rather than the typical UTI caused by ascending infection. MRSA UTIs with associated renal abscesses are an uncommon diagnosis in children that may be caused by a transient bacteremic state secondary to a cutaneous infection.