RBC in Urine 10-15: Management in a 6-Year-Old Girl with Acute Uncomplicated Cystitis
In a 6-year-old girl with acute uncomplicated cystitis, finding 10–15 RBCs per high-power field does not change the antibiotic regimen and does not require further urologic evaluation beyond treating the infection and confirming resolution.
Hematuria in the Context of Acute Cystitis
Microscopic hematuria (≥3 RBCs/HPF) is a common and expected finding in acute cystitis, occurring in the majority of children with urinary tract infections due to bladder mucosal inflammation. 1
The presence of 10–15 RBCs/HPF falls well within the range of hematuria typically seen with uncomplicated UTI and does not by itself indicate complicated infection, urologic malignancy, or glomerular disease in this age group. 1, 2
Hematuria accompanying dysuria, frequency, urgency, or fever strongly suggests UTI as the primary cause, and when leukocytes are also present, the specificity for UTI increases to 96%. 1
Antibiotic Selection Remains Unchanged
First-line empiric therapy for acute uncomplicated cystitis in children should be nitrofurantoin, trimethoprim-sulfamethoxazole (if local resistance <20%), or cephalexin, with treatment duration of 3–7 days depending on the agent. 1, 3, 4
The degree of hematuria (10–15 RBCs/HPF) does not alter antibiotic choice or duration because it reflects the severity of bladder inflammation rather than a different pathogen or resistance pattern. 1
Urine culture should be obtained before starting antibiotics in febrile children or those with suspected pyelonephritis, but empiric therapy can be initiated immediately while awaiting results. 1, 4
When Further Evaluation Is NOT Indicated
In children with isolated microscopic hematuria without proteinuria or dysmorphic RBCs, imaging is not indicated because they are unlikely to have clinically significant renal disease. 2
Hematuria that resolves after successful treatment of UTI requires no additional urologic work-up in an otherwise healthy child without risk factors for structural abnormalities. 2
Do not attribute hematuria to anticoagulation or other medications in children; however, this patient is not on such medications, and the clinical context clearly points to UTI. 2
Post-Treatment Follow-Up
Repeat urinalysis 6 weeks after completing antibiotics is recommended to confirm resolution of both pyuria and hematuria. 1, 2
If hematuria persists beyond 6 weeks post-treatment, further evaluation is warranted, including:
- Examination of urinary sediment for dysmorphic RBCs (>80% suggests glomerular origin) and red cell casts. 2, 5
- Spot urine protein-to-creatinine ratio to assess for significant proteinuria (>0.2 g/g). 2, 5
- Serum creatinine and eGFR to evaluate renal function. 2, 5
- Renal and bladder ultrasound to exclude anatomic abnormalities, stones, or masses. 2
Immediate re-evaluation is warranted if gross hematuria develops, significant increase in microscopic hematuria occurs, new urologic symptoms appear, or hypertension/proteinuria develops. 2, 5
Distinguishing Glomerular from Non-Glomerular Hematuria
Glomerular hematuria is suggested by >80% dysmorphic RBCs, red cell casts, significant proteinuria (protein-to-creatinine ratio >0.5 g/g), or elevated creatinine. 2, 5, 6
Non-glomerular (urologic) hematuria is characterized by normal-shaped RBCs, minimal proteinuria, and absence of casts, which is the expected pattern in acute cystitis. 2, 5
In this 6-year-old with acute cystitis symptoms, the hematuria is almost certainly non-glomerular and secondary to bladder inflammation. 1, 2
Common Pitfalls to Avoid
Do not order imaging (ultrasound, CT) during acute cystitis unless there are features suggesting complicated infection (fever >38.3°C, flank pain, systemic toxicity, known urologic abnormalities). 7, 2
Do not refer to nephrology based solely on 10–15 RBCs/HPF in the setting of acute cystitis without first confirming persistence after infection treatment. 2, 5
Do not delay antibiotic therapy while pursuing extensive hematuria work-up in a symptomatic child with clear evidence of UTI. 1, 4
Do not assume hematuria is benign without follow-up; always confirm resolution after treatment to avoid missing underlying pathology. 2, 5
Pediatric-Specific Considerations
Children with congenital renal abnormalities, history of recurrent UTIs, or family history of kidney disease warrant closer surveillance even if initial hematuria resolves. 7, 2
Gross hematuria in children requires renal and bladder ultrasound to exclude nephrolithiasis, anatomic abnormalities, and rarely tumors, but microscopic hematuria in the context of UTI does not. 2
Traumatic hematuria in children with high-energy mechanism, multiorgan injury, or known congenital anomalies requires contrast-enhanced CT even with only microscopic hematuria, but this scenario does not apply to a child with cystitis. 7, 2