Evaluation and Management of Adolescent Patients with Dysuria and Proteinuria

Immediate Diagnostic Workup

The American College of Radiology recommends obtaining urinalysis with microscopy immediately to assess for red blood cell casts, dysmorphic red blood cells, and acanthocytes, which indicate glomerular disease 1, 2
Quantify proteinuria using either a spot urine protein-to-creatinine ratio or 24-hour urine collection, as 2+ proteinuria on dipstick suggests significant protein excretion that requires quantification for diagnosis and prognosis 2, 3
In children, a spot urine protein-to-creatinine ratio >200 mg/g (>20 mg/mmol) is abnormal and warrants further investigation 2
Measure serum creatinine and calculate eGFR to assess baseline renal function, as proteinuria with impaired kidney function indicates more serious disease 4, 2
Obtain complete blood count with platelets to screen for systemic disease and assess for anemia or thrombocytopenia that may accompany glomerular disease 1

Recent streptococcal pharyngitis suggests post-infectious glomerulonephritis 1
Gross hematuria episodes suggest glomerular bleeding 1
Family history of renal disease, hearing loss, or hematuria suggests hereditary nephritis like Alport syndrome or thin basement membrane disease 1, 5

Measure blood pressure carefully, as hypertension with proteinuria indicates more severe glomerular disease and requires aggressive management 1, 4
Assess for edema, which suggests nephrotic-range proteinuria 1

Tea-colored urine, red blood cell casts, or dysmorphic RBCs with 2+ proteinuria strongly indicate glomerulonephritis requiring nephrology referral 1, 2

Proteinuria >1 g/day (or spot urine protein-to-creatinine ratio >1000 mg/g) requires urgent nephrology referral 4, 6, 2
Presence of red blood cell casts or dysmorphic RBCs requires urgent nephrology referral 1, 2
Elevated serum creatinine or reduced eGFR requires urgent nephrology referral 4, 2
Hypertension requires urgent nephrology referral 1, 4

If glomerular disease is confirmed, refer urgently to pediatric nephrology for consideration of renal biopsy to establish diagnosis 1
Initiate blood pressure control if hypertension is present, targeting <130/80 mmHg (or age-appropriate percentiles in adolescents) 4, 6
Consider ACE inhibitor or ARB therapy if proteinuria >0.5-1 g/day per 1.73 m² and blood pressure allows, as these agents reduce proteinuria and slow progression 4, 6
Restrict dietary sodium to <2 g/day to help control blood pressure and edema 2