Fever and Dysuria

  • Core 1 (Pre-clerkship)
    • Microbiology and Infectious Disease 1, Week 2: Antibiotics
    • Microbiology and Infectious Disease 1, Week 2: Gonorrhea, Chlamydia, and Syphilis
  • Core 2 (Clerkship)
    • Pediatrics Clerkship didactics on Fever
  • Core 3 (Post Clerkship) Electives that may further knowledge
    • Peds ID

Case 1: A 10-month-old male with a history of prior febrile urinary tract infection presents with 3 days of fever without localizing source. Urinalysis shows concern for urinary tract infection.   

Case 2: A 10-year-old female with no past medical history presents with 3 days of burning pain with urination and urinary frequency.  

History: 

  • Symptoms concerning for UTI include dysuria, urinary urgency, urinary frequency, hematuria, suprapubic pain, new urinary incontinence, nausea/vomiting 
  • Infants and young children often present with fever without localizing symptoms 
  • Symptoms more suggestive of pyelonephritis: flank pain, diffuse abdominal pain, fever 
  •  Assess for UTI risk factors 
    • History of prior UTI 
    • Fever duration > 48 hours 
    • No alternative sources of fever (no respiratory symptoms, etc.) 
    • Female or uncircumcised male 
    • History of constipation 
    • History of genitourinary anatomic anomalies 
  • In adolescents, consider taking a history privately to discuss risk factors for STIs or any history of prior STIs 

Physical Exam: 

  • Vitals: may see fever, tachycardia 
  • Abdomen: evaluate for generalized abdominal tenderness, suprapubic tenderness 
  • Back: evaluate for costovertebral angle tenderness, spinal lesions (sacral dimple, sacral hair tuft) as these may raise concern for tethered cord 
  • GU: evaluate for anatomical anomalies (labial adhesions, phimosis), genital rashes or sores, urethral or vaginal discharge 

  • Dysuria: cystitis, vulvovaginitis, urethritis, cervicitis 
  • Dysuria + back/flank pain: pyelonephritis, musculoskeletal back pain, pelvic inflammatory disease, nephrolithiasis, cervicitis 

Evaluation

  • Obtain urinalysis in patients who have dysuria 
    • In children 2 to 23 months of age who cannot accurately report symptoms, use UTI Calculator to calculate risk for UTI
  • Urinalysis and urine culture
    • Method of collection
      • Gold standard for testing for UTI would be a catheterized sample
      • In older children, a clean catch sample can often be obtained
      • Urine bags or cotton balls in diaper are often used to collect urine in infants but you must use caution in interpreting these as the samples will be contaminated with skin flora. NEVER send a urine culture from a bagged specimen.
      • If looking for STIs/cervicitis will need an additional specimen that is not clean catch to pick up on these pathogens.
    • Interpretation of Urinalysis and Urine Culture
      • To diagnose UTI, you need BOTH evidence of inflammation on UA + positive urine culture
        • Urine dipstick showing leukocyte esterase ≥ 2 or nitrite positive
        • Leukocyte esterase is a marker of pyuria. Note this is a nonspecific marker for UTI as it can be seen in many other conditions
        • Nitrites are converted from dietary nitrates in the presence of most Gram-negative enteric bacteria in the urine. Conversion requires urine to be sitting in the bladder for 4 hours, so may not see these in infants. Also, note these are not made by many gram-positive pathogens (ex: enterococus).
        • Microscopy showing ≥ 5 WBC/HPF or bacteriuria
        • Urine culture findings concerning for UTI: ≥ 50,000-100,000 CFUs of bacteria 

Treatment for UTI 

  • Given that it takes ~24 hours for urine cultures to speciate, patients are typically treated empirically with antibiotics for UTI (meaning they are given antibiotics to cover the most common pathogens causing UTI while awaiting culture results).
  • See CHOP’s UTI pathway for recommended first line empiric therapy for suspected UTI or pyelonephritis
  • Once urine culture results are obtained, antimicrobials can be narrowed to cover only the pathogen which grew on culture.  

Indications for additional imaging: Renal Bladder Ultrasound

  • The diagnosis of pyelonephritis can be made with evidence of UTI on UA/culture and presence of suggestive clinical symptoms (fever or back/flank pain), but many providers will also obtain RBUS to assess for urinary tract anomalies or presence of complications such as renal abscess in patients without adequate response to therapy within 48 hours. 
  • RBUS is recommended in all infants aged 2-24 months after first febrile UTI 

  • When interpreting urine studies, it is important to consider how the study was collected in order to determine if the results are reliable.
  • Diagnosis of urinary tract infection requires evidence of inflammation on urinalysis and a positive urine culture.
  • Pyelonephritis is a clinical diagnosis based on evidence of UTI on urinary testing as well as fever or flank/back pain.
  • RBUS is recommended in all infants aged 2-24 months after first febrile UTI to assess for anatomical anomalies in the urinary system.  

Infographic summarizing pediatric UTI risk factors, diagnostic testing methods, criteria for diagnosing UTI, and management recommendations.

The infographic outlines factors that increase the likelihood of UTI in children, recommended urine collection methods, and the diagnostic criteria combining urinalysis findings with a positive urine culture. It also highlights nuances such as contamination risk, positive cultures without pyuria, and the small percentage of febrile infants who have UTIs. Management guidance includes first-line antibiotics, duration of therapy, and when to obtain RBUS or VCUG.

Click the drop down to reveal the correct answers

Q1: An 8 month old, circumcised male with no history of prior UTIs presents with fever to 101F for 3 days.  He had a cough and rhinorrhea during this time.  Is testing for UTI appropriate?

Answer:

Q1: No, use UTI Calculator 

Additional Cases to discuss:

  • 16 year old female presents with pelvic pain and dysuria.What work-up would you complete? 
  • A previously continent 7-year-old male develops incontinence over the last 2 days, occurring both during the day and night. Besides UTI, other diagnostic considerations to investigation?