Nephrolithiasis in Children

Objectives

After completing this article, readers should be able to:

1. Explain why a careful evaluation for nephrolithiasis is appropriate to help guide treatment and provide prognostic advice.

2. Discuss why patients who have nephrolithiasis should have a thorough metabolic evaluation, ideally while at home, not infected, and consuming their regular diet.

3. Explain how to prevent future stones in a patient who has nephrolithiasis, regardless of cause.

4. Describe the risk of recurrent stones in a patient who has a history of one or more calculi.

5. Discuss the consequences of the presence of urinary calculi.

Introduction

Nephrolithiasis occurs following a complex interaction of environment and heredity. Urinary crystals coalesce and precipitate when physical and biochemical conditions disturb a delicate balance of stone-promoting and -inhibiting factors (Fig. 1). Small urinary calculi may pass unnoticed or appear as sandlike sediment in urine. Larger calculi may cause pain or obstruct urinary flow. The prevalence of urinary stones varies by region, being more common in the southeastern United States. Nephrolithiasis affects boys and girls equally and is identified in 1 in 1,000 to 1 in 7,600 hospital admissions. Stones are found most commonly in Caucasian children and rarely in African-American children.

Clinical Presentation

The classic adult presentation of sudden, debilitating flank pain is uncommon in children. Nonetheless, some form of abdominal, flank, or pelvic pain occurs in approximately 50% of children who have urolithiasis, most often in older children and adolescents. Urolithiasis in infants may mimic colic. Gross or microscopic hematuria is found in 33% to 90% of children who have urolithiasis and occurs equally across age groups. Urinary tract infection frequently is the presenting sign of urolithiasis in preschool-age children.

Causes