Proteinuria in children.

Proteinuria is common in children and may represent a benign condition or a serious underlying renal disease or systemic disorder. Proteinuria may occur secondary to glomerular or tubular dysfunction. Although a 24-hour urine protein excretion test is usually recommended, it may be impractical in children. A spot, first-morning urine test for protein/creatinine ratio can be useful in this situation. Proteinuria is usually benign, in the form of transient or orthostatic proteinuria. Persistent proteinuria may be associated with more serious renal diseases. Clinical features from the history, physical examination, and laboratory tests help determine the cause of proteinuria. Treatment should be directed at the underlying cause. Patients with active urinary sediments, persistent and gross hematuria, hypertension, hypocomplementemia, renal insufficiency with depressed glomerular filtration rate, or signs and symptoms suggestive of vasculitic disease may require a renal biopsy and referral to a pediatric nephrologist.