Although the view that waiting tactics for urinary tract infections in children are the main factor in scar changes in the renal parenchyma after pyelonephritis, previous studies have not yet been conducted in prospective studies who confirm or refute it.

The aim of a prospective study by D. Doganis et al. (Greece), was to identify the relationship between the timing of the start of antibiotic therapy and the involvement of the renal parenchyma in the inflammatory process with subsequent scarring.

The study included data from 278 children (153 boys and 125 girls) aged 0.5 to 12 months with a newly diagnosed urinary tract infection. The examination plan for children included an ultrasound of the kidneys and a scintigraphy during the first 18 days after hospitalization.

According to the results, the average duration between the time of infection and the start of antibiotic therapy was 2 days (from 1 to 8 days). Changes in the inflammatory kidney parenchyma were seen in 57% of children. In this case, kidney damage on initial examination was found in 43 of 105 children (41%) who started treatment on the first day, in 43 of 73 (59%) children who started treatment on the second day, 28 of 41 (68%) of the children whose therapy started on the third and 44 of 59 (75%) of the children whose therapy started on the 4th day after infection or later.

Upon re-examination of children with inflammatory changes in the kidneys in the acute phase of infection after 5 to 26 months, scar changes in the renal parenchyma were detected in 51% of the children. The absence of significant differences in the incidence of scar changes at the start of treatment in the early stages, compared to that observed in patient management, allowed the authors to conclude that there was no significant effect of the time of the start of antibiotic treatment in patients with advanced pyelonephritis on the frequency of scarring of the renal parenchyma in the aftermath..

Thus, adequate treatment of the urinary tract infection that was started early, especially the first day after the onset of symptoms of the infection, reduces the likelihood that the renal parenchyma is involved in the inflammatory process in the phase acute infection, but does not prevent scarring.