What is the appropriate initial evaluation and management for a 19-year-old presenting with two days of nausea and vomiting now having dysuria and gross hematuria?

Evaluation and Management of a 19-Year-Old with Nausea, Vomiting, Dysuria, and Gross Hematuria

This patient requires immediate urinalysis with microscopy, urine culture before antibiotics, and urgent urologic evaluation—the combination of gross hematuria with dysuria in a young adult mandates ruling out both urinary tract infection and serious urologic pathology including malignancy, stones, or glomerular disease. 1

Immediate Diagnostic Workup

Confirm True Hematuria and Assess Infection

• Obtain urine culture immediately before starting any antibiotics to identify the causative organism and guide targeted therapy, as the presence of leukocytes strongly suggests infection though does not exclude other pathology 1
• Verify gross hematuria with microscopic urinalysis showing ≥3 RBCs per high-power field, not just dipstick positivity which has limited specificity (65-99%) 1, 2
• Examine urinary sediment for dysmorphic RBCs (>80% suggests glomerular disease) and white blood cell casts (suggests pyelonephritis or interstitial nephritis) to differentiate between glomerular and urologic sources 1

Laboratory Assessment

• Measure serum creatinine and BUN to assess renal function, as the clinical presentation may indicate underlying renal impairment 1
• Obtain complete blood count to evaluate for systemic infection or anemia from blood loss 3
• Check urine pregnancy test in any female of reproductive age before proceeding with imaging 4

Risk Stratification and Differential Diagnosis

High-Risk Features Present

Gross hematuria carries a 30-40% malignancy risk and requires urgent urologic referral regardless of other findings 1, 2. While this patient is young (19 years), the combination of:

• Visible blood in urine (gross hematuria)
• Dysuria and systemic symptoms (nausea/vomiting)
• Two-day duration of illness

...creates a clinical scenario that demands complete evaluation.

Most Likely Diagnoses in Order of Probability

1. Acute Cystitis/Pyelonephritis with Hemorrhagic Component

• Leukocyturia with hematuria and dysuria classically indicates UTI, particularly if accompanied by urgency or frequency 1
• Nausea and vomiting suggest upper tract involvement (pyelonephritis) rather than simple cystitis 4
• However, pyuria does not exclude other serious pathology—never delay complete evaluation based solely on presumed infection 1

2. Urolithiasis (Kidney Stone)

• The combination of abdominal pain and hematuria most commonly indicates urolithiasis 5
• Nausea and vomiting are common with renal colic 6
• Dysuria can occur as stone passes through ureter 7

3. Glomerulonephritis or Acute Interstitial Nephritis

• Tea-colored urine with proteinuria and dysmorphic RBCs would suggest glomerular disease 3, 1
• Post-infectious glomerulonephritis can follow recent strep throat 3

4. Less Likely but Must Exclude: Malignancy

• While uncommon at age 19, gross hematuria mandates evaluation regardless of age 2

Imaging Strategy

Initial Approach

Do not proceed with imaging until infection is excluded and renal function is assessed 1. The imaging pathway depends on urinalysis results:

If urine culture is positive (UTI confirmed):

• Treat with appropriate antibiotics based on culture results
• Re-evaluate within 48-72 hours—if symptoms persist despite appropriate antibiotics, this effectively rules out simple UTI and mandates further investigation 1
• If hematuria resolves after treating infection in this low-risk patient, no additional imaging needed 1

If urine culture is negative and symptoms persist:

• Obtain renal and bladder ultrasound to evaluate for stones, hydronephrosis, or structural abnormalities 1
• CT urography without contrast may be obtained if ultrasound is negative but clinical suspicion for urolithiasis remains high, particularly if detection of a stone would impact treatment decisions 1

Treatment Approach

Empiric Management While Awaiting Culture

Initiate empiric antibiotics after obtaining urine culture, adjusting based on susceptibility results, and ensure adequate hydration to maintain urine output and prevent further renal injury 1

For suspected pyelonephritis (given nausea/vomiting):

• Fluoroquinolone (ciprofloxacin or levofloxacin) OR
• Ceftriaxone 1-2g IV/IM daily
• Ensure adequate hydration 1

Symptomatic Management

• Antiemetics for nausea/vomiting (ondansetron 4-8mg) 6
• NSAIDs or acetaminophen for pain (avoid NSAIDs if renal function impaired) 6
• Aggressive hydration if not contraindicated 1

Critical Red Flags Requiring Urgent Action

Immediate urologic referral if:

• Gross hematuria develops or persists—this carries 30-40% malignancy risk regardless of age 1, 2
• Serum creatinine rises or fails to improve within 3-5 days of treatment 1
• Development of significant proteinuria (protein-to-creatinine ratio >0.5 g/g), which would suggest glomerular disease requiring nephrology referral 1

Consider nephrology referral if:

• Creatinine continues to rise or does not improve within 3-5 days 1
• Dysmorphic RBCs >80% or red cell casts present 1
• Significant proteinuria develops 1

Follow-Up Protocol

Re-evaluate within 48-72 hours regardless of initial treatment:

• Repeat urinalysis to confirm resolution of hematuria
• Assess response to antibiotics if infection was treated
• If symptoms persist despite appropriate therapy, proceed immediately to imaging 1

If initial evaluation negative but hematuria persists:

• Repeat urinalysis at 6,12,24, and 36 months with blood pressure monitoring 1

Common Pitfalls to Avoid

• Never assume UTI explains gross hematuria without complete evaluation—infection may coexist with malignancy or stones 1
• Do not delay imaging if symptoms persist beyond 72 hours of appropriate antibiotic therapy 1
• Do not skip urine culture before starting antibiotics—this is essential for targeted therapy 1
• Remember that a significant number of patients with urolithiasis do not have hematuria, so its presence supports but does not confirm stone disease 5