Acute pyelonephritis in children with minimal or normal urine findings

BACKGROUND: Over the past years we have seen several children with serious bacterial infections in whom the focus of the infection was found in the kidneys despite of normal or minimal urine findings. MATERIAL AND METHODS: We review the cases of all children hospitalised at our paediatric department from 1995-2000 with normal or minimal urine findings, and in whom acute pyelonephritis was diagnosed by means of computerized tomographic imaging of the kidneys. RESULTS: All 10 children (aged 9 months to 9 years) had focal areas of decreased enhancement in the kidney parenchyma. All received intravenous antibiotic treatment. Vesicouretheral reflux was detected in four patients and required surgical intervention in one. One patient had considerable renal scarring and decreased renal function on dimercaptosuccinic acid (DMSA) scintigraphy. INTERPRETATION: In children with suspected serious bacterial infection, it is important to have the possibility of renal infection in mind in spite of normal urine findings. The importance of establishing the right diagnosis lies in the fact that patients with pyelonephritis need further investigation and follow-up.