History and Physical Urinalysis to confirm RBCs Directed evaluation studies based on suspected cause Cause apparent on H&P e.g. UTI, trauma, kidney stone, GN Urinalysis Cause not apparent on H&P Urine microscopy Negative for blood Positive for blood Hemolytic anemia Rhabdomyolysis Minimal RBCs RBCs confirmed Isolated microscopic hematuria Urine culture Urine calcium to creatinine ratio Urine protein to creatinine ratio Serum chemistries Serum albumin C3 and C4 complement Complete blood count Renal ultrasound Renal biopsy in selected cases RBCs confirmed Symptomatic microscopic hematuria or gross hematuria
Urate crystals in infants Medications, foods, dyes
Tests to consider if hematuria persistent: Urine calcium to creatinine ratio Test first degree relatives for hematuria Hgb electrophoresis to rule out sickle cell Serum chemistries Renal ultrasound
Figure 163-1 Suggested algorithm for evaluation of red urine/hematuria. GN, Glomerulonephritis; H&P, history and physical; Hgb, hemoglobin; RBCs, red blood cells; UTI, urinary tract infection.
develop progressive renal failure and sensorineural hearing loss during adolescence and young adulthood. Females typically have a more benign course but usually have at least microscopic hematuria. Thin basement membrane disease (benign familial hematuria) is caused by more benign mutations leading to a thinning of the GBM. The mutation is often autosomal dominant, and therefore hematuria is often noted in first-degree relatives. As opposed to Alport syndrome, thin basement membrane disease is typically not progressive and usually has an excellent prognosis.
The presentation of nonglomerular causes of hematuria is more variable and related to the underlying etiology. Hematuria due to tubular disorders is usually only microscopic and may be associated with proteinuria, glycosuria, and polyuria. These children typically do not have hypertension and only develop renal insufficiency with more severe disease. Painless gross hematuria may be seen with sickle cell trait/disease, Wilms tumor, and strenuous exercise. Hematuria may or may not be associated with pain when due to cystic bleeding and Nutcracker syndrome. Gross hematuria following trauma may signify more severe renal or lower urinary tract injury. UTI is associated with typical symptoms such as dysuria and urinary frequency. Urolithiasis may be associated with asymptomatic hematuria or with flank or abdominal pain. Hypercalciuria can cause both gross and microscopic hematuria and may be associated with urinary tract symptoms such as dysuria and urinary frequency or may be asymptomatic.
All patients with hematuria should have a careful history and physical (including blood pressure) along with a urinalysis, including microscopic examination to identifyRBCs. Glomerular hematuria is suggested by a brownish (teaor cola-colored) appearance of the urine and the presence ofRBC casts and/or dysmorphic RBCs on urine microscopy.A urine color that is more bright red in appearance withoutRBC casts or dysmorphic RBCs is more suggestive of a lowerurinary tract source. However there may be overlap of thesefindings.
A suggested algorithm for the evaluation of hematuria is given in Figure 163-1. Gross hematuria and microscopic hematuria with associated concerning findings should have additional laboratory evaluation. The presence of low C3 complement narrows the differential diagnosis to PSGN, membranoproliferative GN, and lupus nephritis. Children with isolated asymptomatic microscopic hematuria may be observed with repeat urinalyses. If the hematuria is persistent, additional evaluation may be appropriate.