Diagnostic Approach to a Child with Vomiting and Hematuria

Immediate Diagnostic Priorities

The American Academy of Pediatrics recommends that children with vomiting and hematuria undergo urgent urinalysis with microscopic examination and renal ultrasound to differentiate between urinary tract infection and more serious causes of hematuria 1, 2, 3
A recent streptococcal infection suggests post-infectious glomerulonephritis, and its presence should be investigated 4
The presence of fever, dysuria, frequency, or crying during urination increases the likelihood of UTI 1, 2
Recent trauma or strenuous exercise may cause transient hematuria 5, 4
A family history of renal disease, hearing loss, or sickle cell disease is relevant to the diagnosis 5, 4
Foul-smelling urine suggests UTI 1
The American College of Emergency Physicians recommends assessing for fever, as it is the most common symptom of UTI in children under 5 years 1, 2
Costovertebral angle tenderness suggests pyelonephritis 5, 4
The presence of an abdominal mass is a critical red flag requiring urgent imaging for possible Wilms tumor 4, 6
Hypertension suggests glomerular disease 7
Rash, arthritis, or soft-tissue edema suggests systemic disease 5, 4

The American Academy of Pediatrics recommends performing urinalysis with microscopic examination within 24 hours to differentiate UTI from glomerular disease 1, 3
Tea-colored urine with proteinuria, red blood cell casts, and dysmorphic RBCs indicate glomerular disease 3, 5, 4
White blood cells and microorganisms confirm UTI 3, 5
The American College of Radiology recommends obtaining urine culture before starting antibiotics 3
Clean-catch or urethral catheterization is the recommended method for urine collection, rather than bag collection, due to high false-positive rates 3
If glomerular disease is suspected, obtain blood urea nitrogen, serum creatinine, and complete blood count 5, 4
Spot urine calcium-to-creatinine ratio should be evaluated to assess for hypercalciuria 5, 4

The American College of Radiology recommends obtaining renal ultrasound after confirming UTI with urine culture, as all children under 6 years with first febrile UTI require imaging to detect congenital or acquired abnormalities 5, 4
Ultrasound identifies structural lesions, kidney size, and anatomic abnormalities 5, 4
If the child has macroscopic hematuria without fever or clear infection, perform renal and bladder ultrasound as first-line imaging 5, 4
Plain radiography may be added to detect calcifications or radiopaque stones 4

The Centers for Disease Control and Prevention recommends providing oral rehydration with small, frequent volumes (5 mL every minute initially) for vomiting associated with UTI or other causes 8
Correction of dehydration often lessens vomiting frequency 8
Replace ongoing losses with oral rehydration solution 8

The American Academy of Pediatrics recommends monitoring for long-term complications including hypertension and chronic kidney disease 1