Severe renal inflammatory disease in childhood: Incidence, imaging and therapeutics

Background: Severe renal inflammatory disease is rare in childhood. We undertook this study to investigate the incidence, imaging and therapeutics of severe renal inflammatory disease in children with urinary tract infection (UTI). Materials and methods: Routine ultrasound scanning was performed in 703 children with culture-proven UTI. Computerized tomography, intravenous pyelography, and voiding cystourethrography were also performed when necessary. Intensive antibiotic therapy was administered in all cases. Percutaneous ultrasound guided drainage or surgery was performed when indicated. Results: Among 703 children with UTI, 16 cases of severe renal inflammatory disease were detected, including five with acute focal bacterial nephritis (AFBN), two of renal abscess, and nine of pyonephrosis, resulting in a total incidence of 2.28%. On ultrasound scanning, AFBN presented as a hypoechoic mass or isoechoic swelling in one or several lobes of the kidney, while renal abscess presented as an anechoic round mass with a clear border in the renal parenchyma. Moving echogenic material filling the dilated renal pelvis was demonstrated in pyonephrosis. E coli was the most common isolate in our series. All cases of AFBN and one of renal abscess were successfully treated with antibiotics. Surgery was necessary in the remaining cases. Vesicoureteral reflux was detected in two cases of AFBN and renal abscess, while urinary obstruction was detected in all nine cases of pyonephrosis. Conclusion: Ultrasound facilitates early detection of severe renal inflammatory disease, differentiates AFBN and renal abscess, and helps to plan and monitor therapeutics.