Diagnostic Imaging in Pediatric Renal Inflammatory Disease

Abstract

THE TERM "renal inflammatory disease" encompasses a broad spectrum of conditions in pediatrics. These include diffuse pyelonephritis, focal pyelonephritis, renal abscess, pyonephrosis, and pararenal retroperitoneal abscesses due to infection of the urinary tract. Uncomplicated pyelonephritis does not require imaging for diagnosis if the clinical presentation and laboratory data are characteristic. However, the signs and symptoms of infection of the upper urinary tract in children may present a diagnostic challenge.During the neonatal period, infections of the urinary tract are more common among boys and nonspecific symptoms predominate. These include poor feeding, slow gain in weight, vomiting, diarrhea, irritability, and jaundice. Fever or hypothermia also is often present. Bacteremia occurs in approximately 35% of newborns with infection of the urinary tract.1 In infants aged 1 month to 2 years, nonspecific manifestations still predominate, but sepsis and severe illness are less frequent than in the neonate.Among ambulatory children younger than 2 years, whose only symptom is fever, infection of the urinary tract is the cause in an important number of cases. In one multicenter study, eight (7.4%) of 108 febrile girls but none of 85 boys had infection of the urinary tract.2 In contrast, in a single pédiatrie practice, 19% of 156 children of all ages with isolated fever had proved infec-tion of the urinary tract; if abdominal pain was an additional finding, 31% had infection of the urinary tract.3 In preschool and school-age children with infection of the urinary tract, dysuria is a frequent symptom. Associated findings can include abdominal pain or pain in the flank, frequency, urgency, enuresis, fever, and abnormal urine odor. Poor gain in weight, vomiting, and diarrhea are unusual.