Evidence favours the oral route and a short course of appropriate antibiotics

A 9 month old girl presents with high fever, vomiting, lethargy, and bacteriologically confirmed urinary tract infection. The diagnosis is clear—acute pyelonephritis. This is a common problem and the cause of about 5% of febrile episodes in children.1 But how should she be treated? Which antibiotics should be given and by which route? For how long should antibiotics be given? This article summarises what we know about treatment of acute pyelonephritis from randomised trials and what we think we know about treatment, based on clinical experience.

Acute pyelonephritis comprises urinary tract infection with systemic features including fever, vomiting, abdominal or loin pain, and lethargy. Fever is the most useful symptom clinically. Compared with the reference standard for pyelonephritis—technetium-99m dimercaptosuccinic acid scanning—fever is very sensitive but has only moderate specificity. In few afebrile children—except very young infants—the renal parenchyma is affected. Conversely in about 50% of children with clinical pyelonephritis the renal parenchymal is affected.

The major decisions about treatment that are to …