UTIs in teens (CME)

July 1, 2009

A review of the reasons why urinary tract infections are so prevalent in teenagers, and tips on how to distinguish them from sexually transmitted infections.

These infections are characterized by a wide range of symptoms and disease severity, ranging from cystitis (lower-tract infection involving the bladder and proximal urethra) to pyelonephritis (upper-tract infection of the kidney that can present with systemic symptoms and progress to sepsis). Adolescent UTIs present pediatricians with several challenges. Not only are they diagnosed and treated differently than are UTIs in younger children, but in teens UTIs must be differentiated from sexually transmitted infections (STIs) and vaginitis, with which they share many symptoms. And though the American Academy of Pediatrics has issued practice parameters for UTIs in children younger than 2, no similar guidelines are available for adolescents.

The following recommendations are intended to help pediatricians evaluate adolescents with urinary or vaginal symptoms for a UTI, using a targeted history, physical examination, and laboratory tests-and to provide appropriate management.

Urinary tract disease is second only to injuries as the most common discharge diagnosis for emergency department visits by adolescents.2 Risk factors include being female, being sexually active, instrumentation of the urinary tract, and urinary tract abnormalities.

Being female is a risk factor for a UTI at any age because the shorter female urethra is in close proximity to the rectal and vaginal areas, leading to periurethral colonization. Periurethral bacteria then ascend into the bladder, a process that can be facilitated by urethral massage during sexual intercourse.

Sexual activity is the major risk factor for UTIs in both sexes, which helps to explain why UTIs are so prevalent in adolescence. Sexually active adolescent girls are most at risk for UTIs; in college females, an incidence rate of 0.7 infections per person-year has been reported.3 UTIs are unusual in virginal adolescent girls.4,5

Numerous factors related to sexual activity are associated with UTIs. Spermicide-coated condoms have been shown to alter the vaginal flora, allowing for colonization of the urethra with enteric organisms, which increases the risk for UTIs.6 Other sex-related factors identified in young women include high coital frequency, recent sexual intercourse, not voiding after coital activity, being pregnant, and diaphragm use.6,7 For young men, sexual contact with a partner afflicted with a UTI has been associated with subsequent infection,8 as has anal sex.

Structural and functional urinary tract abnormalities may predispose an adolescent to UTIs, though these conditions are more likely to present at a younger age. Vesicoureteral reflux and obstructive uropathies such as urethral strictures and labial adhesions are examples of such abnormalities. Because UTIs are much less prevalent in males than females, males with UTIs would appear to be more at risk of having a structural or functional urinary tract abnormality. A small study among healthy male university students, however, showed that the only differences between those with and without UTIs was that young men with UTIs were slightly older.9 Another study found no genitourinary tract abnormalities in 29 men hospitalized for a first UTI.10

Other risk factors include instrumentation of the urinary tract and poor hygiene, which increase the risk of UTIs among both genders and in all age groups, including adolescents. Not being circumcised is an additional risk factor for young males with no structural defects.11

Risk factors for recurrent infections are similar to those associated with an initial infection but also include having a first UTI under age 15 and a maternal history of UTIs.12 In addition, having an initial UTI caused by Escherichia coli was associated with an increased risk for subsequent UTIs in the next six months.13 Recurrent infections are common in adolescents: Almost 30% of young women will experience an additional infection.13