Diagnosis and treatment of urinary tract infections in children.

Acute urinary tract infections are relatively common in children, with 8 percent of girls and 2 percent of boys having at least one episode by seven years of age. The most common pathogen is Escherichia coli, accounting for approximately 85 percent of urinary tract infections in children. Renal parenchymal defects are present in 3 to 15 percent of children within one to two years of their first diagnosed urinary tract infection. Clinical signs and symptoms of a urinary tract infection depend on the age of the child, but all febrile children two to 24 months of age with no obvious cause of infection should be evaluated for urinary tract infection (with the exception of circumcised boys older than 12 months). Evaluation of older children may depend on the clinical presentation and symptoms that point toward a urinary source (e.g., leukocyte esterase or nitrite present on dipstick testing; pyuria of at least 10 white blood cells per high-power field and bacteriuria on microscopy). Increased rates of E. coli resistance have made amoxicillin a less acceptable choice for treatment, and studies have found higher cure rates with trimethoprim/sulfamethoxazole. Other treatment options include amoxicillin/clavulanate and cephalosporins. Prophylactic antibiotics do not reduce the risk of subsequent urinary tract infections, even in children with mild to moderate vesicoureteral reflux. Constipation should be avoided to help prevent urinary tract infections. Ultrasonography, cystography, and a renal cortical scan should be considered in children with urinary tract infections.