Review Question - QID 104600

This child has asymptomatic proteinuria, most likely to be transient proteinuria. The most appropriate next step is to repeat dipstick analysis.

Proteinuria in a child can be transient, orthostatic, or persistent. Transient proteinuria is the most common cause. Transient proteinuria may be induced by vigorous exercise, fever, or stress. In an asymptomatic child with a positive dipstick for protein, the majority of cases are due to transient proteinuria. Accordingly, the next step is to repeat the dipstick on another occasion. If the proteinuria has resolved on repeat testing, transient proteinuria is confirmed, and no further work-up in necessary at that time.

Leung et al. discuss proteinuria in children. Proteinuria is a common finding in children, and may signal underlying pathology or may be benign. If repeat dipstick examination suggest the need for further work-up, 24-hour urine collection may be used as a good next test. Alternatively, spot early morning urine-protein-to-creatinine ratio may also be useful, particularly in very young children for whom a 24-hour collection would be difficult to complete.

Loghman-Adham discusses the prevalence and etiology of proteinuria in children. Proteinuria is most commonly transient or intermittent, and frequently follows strenuous exercise, emotional stress, surgery, febrile illness, or seizures. When multiple urine specimens are tested for a single child, the detection of proteinuria in a single of the specimens may reach nearly 11%. The large majority of children who test positive on a single sample will be negative on a repeat sample. In most cases, an extensive work-up in not necessary.

Illustration A depicts an algorithm for evaluation of transient proteinuria.

Incorrect Answers:
Answer 2: The patient has no symptoms of urinary tract infection, and thus urine culture is not indicated.
Answer 3: Renal ultrasound may be appropriate following repeated positive testing or if the patient has symptoms or additional exam findings, but is not the appropriate next step in a child who is asymptomatic and has a single positive urine dipstick for protein.
Answers 4-5: To diagnose orthostatic proteinuria, or for further work-up following a repeat positive dipstick, urine-protein-to-creatinine ratios or 24-hour collections may be appropriate.