Renal and peri-renal abscesses in children: proposed physio-pathologic mechanisms and treatment algorithm.

Renal and perinephric abscess in children are uncommon. Three basic pathophysiologic mechanisms are involved, namely, hematogenous spread, ascending infection and contamination by proximity to an infected area. Six pediatric patients diagnosed with renal abscess were treated at our institution from 1990-2000. Five patients were females; ages ranged from 3-17 years (mean 11.8 years). Diagnosis, as expected, was not readily apparent at presentation. Computerized tomography and renal sonograms were the most useful imaging modalities. Gram-negative bacteria were commonly isolated; only one patient grew Staphylococcus aureus. All patients received broad-spectrum intravenous antibiotics. Additional treatments consisted of percutaneous drainage (4 patients), exploratory laparotomy (1 patient, for presumed Wilm's tumor) and nephrectomy (2 patients). A new classification of the etiologic mechanisms of this condition is proposed along with a simple and practical treatment algorithm.