Following a first urinary tract infection, 15% of patients develop renal scarring detectable with renal scintigraphy.[30]Shaikh N, Ewing AL, Bhatnagar S, et al. Risk of renal scarring in children with a first urinary tract infection: a systematic review. Pediatrics. 2010 Dec;126(6):1084-91.
http://www.ncbi.nlm.nih.gov/pubmed/21059720?tool=bestpractice.com
Vesicoureteral reflux increases the risk of renal scarring, especially at higher grades.[83]Mattoo TK, Chesney RW, Greenfield SP, et al; RIVUR Trial Investigators. Renal scarring in the randomized intervention for children with vesicoureteral reflux (RIVUR) trial. Clin J Am Soc Nephrol. 2016 Jan 7;11(1):54-61.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4702233
http://www.ncbi.nlm.nih.gov/pubmed/26555605?tool=bestpractice.com
[93]Najafi F, Sarokhani D, Hasanpour Dehkordi A. The prevalence of kidney scarring due to urinary tract infection in Iranian children: a systematic review and meta-analysis. J Pediatr Urol. 2019 Aug;15(4):300-8.
http://www.ncbi.nlm.nih.gov/pubmed/31229416?tool=bestpractice.com
The risk of scarring is reduced by prompt administration of antibiotics to febrile children with UTI.[26]Shaikh N, Mattoo TK, Keren R, et al. Early antibiotic treatment for pediatric febrile urinary tract infection and renal scarring. JAMA Pediatr. 2016 Sep 1;170(9):848-54.
http://www.ncbi.nlm.nih.gov/pubmed/27455161?tool=bestpractice.com
Nevertheless, most children with UTI do not have any long-term sequelae.[94]Salo J, Ikäheimo R, Tapiainen T, et al. Childhood urinary tract infections as a cause of chronic kidney disease. Pediatrics. 2011 Nov;128(5):840-7.
http://www.ncbi.nlm.nih.gov/pubmed/21987701?tool=bestpractice.com
Recurrent upper UTI can lead to renal scarring and renal impairment.[95]Kosmeri C, Kalaitzidis R, Siomou E. An update on renal scarring after urinary tract infection in children: what are the risk factors? J Pediatr Urol. 2019 Dec;15(6):598-603.
https://www.doi.org/10.1016/j.jpurol.2019.09.010
http://www.ncbi.nlm.nih.gov/pubmed/31591046?tool=bestpractice.com
Children who are immunocompromised or who have structural or functional renal abnormalities are at an increased risk of recurrent infection.[83]Mattoo TK, Chesney RW, Greenfield SP, et al; RIVUR Trial Investigators. Renal scarring in the randomized intervention for children with vesicoureteral reflux (RIVUR) trial. Clin J Am Soc Nephrol. 2016 Jan 7;11(1):54-61.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4702233
http://www.ncbi.nlm.nih.gov/pubmed/26555605?tool=bestpractice.com