Laboratory Studies
Perform a complete urinalysis and urine culture for any child who presents with symptoms suggestive of a urinary tract infection (UTI). Diagnosis is made on the basis of the presence of both pyuria and at least 50,000 colonies/mL of a single uropathogenic organism in an appropriately collected specimen of urine. [15, 16]
Hematuria in the absence of infection and the evaluation of urinary incontinence are beyond the scope of this article but merit thorough investigation (see Hematuria, Urinary Incontinence).
In cases of urethral prolapse, obtaining a culture from the prolapsed mass or from any associated vaginal discharge may be useful.
Imaging Studies
Voiding cystourethrography (VCUG) and renal and bladder ultrasonography (US) have generally been considered to be indicated for all patients with culture-proven UTIs. According to the 2011 American Academy of Pediatrics (AAP) guideline on diagnosis and management of the initial UTI in febrile infants and children aged 2-24 months, [15] which was reaffirmed in 2016, [16] VCUG is not recommended routinely after the first UTI but is indicated if renal and bladder US reveals hydronephrosis, scarring, or other findings suggestive of high-grade vesicoureteral reflux (VUR) or obstructive uropathy; if other atypical or complex clinical circumstances are present; or if there is a recurrence of a febrile UTI.
In the absence of UTIs, most suspected urethral lesions can be documented with VCUG or retrograde urethrography (RUG). [17]
Evaluation of the upper tracts with US, nuclear scanning, or intravenous pyelography (IVP) is particularly important in patients with anterior urethral valves (AUVs), urethral duplications, megalourethras, urethral diverticula, polyps, or Cowper duct cysts because various degrees of obstructive uropathy may be present and may affect the upper urinary tract and kidneys. [18, 19]
US examinations during the second trimester of pregnancy can help detect some anomalies in the fetal urinary tract. [20]
In patients with megalourethras and urethral duplications, additional imaging studies may be necessary because of the high incidence of associated anomalies.
Patients with urethral prolapse do not require further evaluation of their urinary tracts. However, if the diagnosis is in question, performing bladder US to exclude a bladder rhabdomyosarcoma is reasonable.
Magnetic resonance imaging (MRI) is playing an evolving role in the evaluation of stress urinary incontinence. [21]
Procedures
Cystoscopy can be used to clarify a diagnosis or for therapeutic purposes.
