[Acute pyelonephritis in children].

In children, pyelonephritis (or upper urinary tract infection) exposes to systemic complications and renal sequelae. The diagnosis rests on cytobacteriological examination of urine, but its results are difficult to interpret in neonates and small infants due to the possible contamination of urine collected in bags. It is recommended to repeat samplings in order to confirm a positive result or to collect the urine by a reliable technique such as puncture of the bladder. In 50% of the cases urinary infection reveals a urinary tract abnormality to be localized in all cases by ultrasonography and cystography completed, if there is any doubt, by intravenous urography. In infants younger than 18 months antibiotic therapy consists of a third generation cephalosporin administered, jointly with an aminoside, by the parenteral routes for at least 10 days. Older children with a better tolerance of the infectious syndrome may be treated with a betalactam antibiotic (amoxicillin-clavulanic acid or cephalosporin) injected alone or with cotrimoxazole administered orally. The effectiveness of treatment is tested by a bacteriological examination of the urine 48 hours after the end of therapy. Antibiotic prophylaxis to avoid recurrences is prescribed after the curative treatment until cystography is performed.