The decrease in pediatric sepsis, meningitis, and occult bacteremia
over the past two decades due to successful immunizations has made urinary tract
infection (UTI) a relatively more common cause of fever in young children,
and UTI is now the most common serious bacterial infection in children.
Consider UTI as a possible diagnosis in all febrile infants and young
children presenting to EDs, and in all older children with abdominal
or urinary symptoms whether or not there is fever.
Estimates of UTI prevalence are highly variable depending upon
the population. Approximately 1% of boys and 3% of
girls are diagnosed with UTI before puberty.1 Among
young children presenting to EDs with fever and no obvious source of infection, between 3% and
8% have UTI.2,3 Younger age, non-black
race/ethnicity, female sex, and uncircumcised male are
some of the baseline characteristics that increase the risk of UTI
(Table 126-1).2–4 For
example, male and female infants <3 months of age have a higher
prevalence of UTI than older infants and toddlers.3 It
is unclear why black children have a lower risk of UTI, but this
has been consistently noted in studies of UTI prevalence.5
Table 126-1 Factors
That Affect Prevalence of Urinary Tract Infection
| Save Table
Table 126-1 Factors
That Affect Prevalence of Urinary Tract Infection
|Gender||Three times higher risk in females|
|Age||Variably increased risk in younger children and infants|
|Circumcision status||10 times higher risk in uncircumcised males|
|Race/ethnicity||One half the risk among black children|
|Genital sexual activity||Increased risk|
|Previous urinary tract infection||Increased risk|
Young children with UTI usually have upper tract involvement
and fever, and older children tend to develop isolated cystitis
without systemic involvement. Determining the baseline prevalence
of UTI based on demographic and historical information allows for
more informed decisions about subsequent diagnostic testing and
UTI is most commonly caused by bacteria, although viruses and
other infectious agents can also be urinary pathogens. The vast
majority of UTIs in all age groups occur when perineal-fecal bacteria
ascend the urethra and enter the bladder. Escherichia coli is
the most common cause of UTI in children, and this is likely due
to its ubiquitous presence in stool combined with bacterial virulence
factors that improve adhesion and ascent of the urethra.1 Mechanical
defenses in humans, such as normal urinary outflow, clear most bacteria
that are introduced into the bladder. Anatomic abnormalities can
make bacterial proliferation or persistence in the bladder more
likely. There are occasionally patients, usually preschool or school-aged
females, who have recurrent UTI without a clear anatomic abnormality.
Some of these patients likely have abnormal bladder function due
to constipation, whereas others will not have any identifiable risk
factors. Rare causes of UTI in children include indwelling urinary
catheters or UTI from embolism or secondary to infection of other
The initial history should focus on the acute illness, including
the presence of fever, vomiting, abdominal pain, and questioning
about symptoms that might suggest another source of fever such as
rhinorrhea, cough, diarrhea, etc. In verbal and toilet-trained children,
the presence of new-onset enuresis, dysuria, polyuria, abdominal
pain, back pain, or vaginal or penile discharge is important. GU
symptoms in a verbal child should always trigger consideration of
UTI. In nonverbal children, a history of high [>40°C
(104°F)] or prolonged fever appears to be one of the most
predictive symptoms of UTI.5 Additionally,
a history of prolonged hyperbilirubinemia in infants has been associated
with UTI.6 Conversely, parental report of “smelly” urine
does not appear to be helpful.7
Medical history should include a prenatal history and ascertainment
of whether a late-term prenatal US was obtained. A normal late-term
US decreases the likelihood of some GU abnormalities that could
increase the risk of UTI. Additionally, a previous history of UTI
and family history of UTI is important to guide subsequent evaluation.
UTI can be associated with fever, vomiting, and abdominal pain.
In older children, urethral or bladder symptoms, in addition to
localized flank pain, can all occur.
Assess the child’s health and degree of acute illness.
If the child is lethargic, dehydrated, or in respiratory distress,
then institute appropriate therapy. Examine the genitalia for anatomic
abnormalities (e.g., labial adhesions, phimosis) or other causes
of GU symptoms. Note circumcision status in male infants. Perform
a careful abdominal and groin examination to evaluate for suprapubic
tenderness,5 costovertebral angle tenderness, hernias, and
any abnormal masses. A complete physical examination helps to exclude
other causes of illness. Although the presence of another
source of fever lowers the risk of UTI, it can coexist with other
common viral syndromes such as respiratory syncytial virus bronchiolitis.5,8,9
In infants and young children, the only cardinal feature
of UTI is a febrile illness without other definitive source. In
verbal children, dysuria combined with suprapubic tenderness on
examination is the classic constellation of symptoms and signs.
Additionally, in children with febrile illnesses and atypical presentations
for UTI [e.g., bronchiolitis with a temperature of 40°C
(104°F)], obtain urine cultures.9,10
There are no clinical criteria that confirm the diagnosis of
UTI in young children without urinary testing. In adolescents, symptoms
of dysuria with no vaginal or urethral discharge, or an examination
consistent with UTI/pyelonephritis, such as suprapubic
or costovertebral angle tenderness, allow a presumptive diagnosis
of UTI. In all young children, and in most adolescents, the definitive
diagnosis of UTI is based on urine culture.
Diagnosis of Consequence
UTI is a possible diagnosis in all infants with fever. In children
with dysuria but no fever, the most common concerns are listed in Table 126-2.
Table 126-2 Causes of Either
Culture-Negative Dysuria ...
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