New renal scarring in children who at age 3 and 4 years had had normal scans with dimercaptosuccinic acid: follow up study.
OBJECTIVE
To determine up to what age children remain at risk of developing a new renal scar from a urinary tract infection.


METHODS
Follow up study. Families of children who had normal ultrasound scans and scanning with dimercaptosuccinic acid (DMSA) after referral with a urinary tract infection when aged 3 (209) or 4 (220) were invited to bring the children for repeat scans 2-11 years later. A history of infections since the original scan was obtained for children not having a repeat scan.


METHODS
Teaching hospital.


METHODS
Children from three health districts in whom a normal scan had been obtained at age 3-4 years in 1985-1992 because of a urinary tract infection.


METHODS
Frequency of new renal scars in each age group.


RESULTS
In each group, about 97% of children either had repeat scanning (over 80%) or were confidently believed by their general practitioner or parent not to have had another urinary infection. The rate of further infections since the original scan was similar in the 3 and 4 year old groups (48/176 (27%)) and 55/179 (31%)). Few children in either group known to have had further urinary infections did not have repeat scanning (3/209 (1.4%) and 4/220 (1.8%)). In the 3 year old group, 2.4% (5/209) had one or more new kidney scars at repeat scanning (one sided 95% confidence interval up to 5.0%), whereas none of the 4 year olds did (one sided 95% confidence interval up to 1.4%). The children who developed scars were all aged under 3.4 years when scanned originally.


CONCLUSIONS
Children with a urinary tract infection but unscarred kidneys after the third birthday have about a 1 in 40 risk of developing a scar subsequently, but after the fourth birthday the risk is either very low or zero. Thus the need for urinary surveillance is much reduced in a large number of children.
Vernon
S J
SJ
Department of Child Health, Royal Victoria Infirmary, Newcastle upon Tyne.
Coulthard
M G
MG
Lambert
H J
HJ
Keir
M J
MJ
Matthews
J N
JN
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002921:Cicatrix / Q000000981:diagnostic imaging* / Q000209:etiology; D005500:Follow-Up Studies; D006801:Humans; D007674:Kidney Diseases / Q000000981:diagnostic imaging* / Q000209:etiology; D011877:Radionuclide Imaging; D012307:Risk Factors; D004113:Succimer; D014552:Urinary Tract Infections / Q000150:complications / Q000000981:diagnostic imaging*
D004113:Succimer