# Urolithiasis in Children—Clinical Picture, Pathogenesis, and Diagnostic Approach

## TL;DR

This paper reviews how kidney stones in children are often caused by metabolic issues and highlights the importance of diagnosing these underlying problems to prevent recurrence.

## Contribution

The paper emphasizes metabolic disturbances as a key cause of kidney stones in children and outlines diagnostic steps specific to pediatric cases.

## Key findings

- Metabolic disturbances are the most common cause of recurrent urolithiasis in children in Europe and North America.
- Idiopathic hypercalciuria preceded by hypocitraturia is the most frequent metabolic disturbance in pediatric urolithiasis.
- A comprehensive metabolic evaluation is essential for diagnosing and preventing recurrence of kidney stones in children.

## Abstract

As in adults, urolithiasis is a significant health problem in children from an early age, having a very negative impact on health and quality of life and potentially leading to kidney function impairment. The occurrence of deposits in the urinary tract in a child is almost always the result of significant predisposing factors, including metabolic defects involving the kidney or the entire body (often inherited in a Mendelian fashion), urinary tract defects, or urinary tract infections. Among metabolic disturbances, idiopathic hypercalciuria, preceded by hypocitraturia, is the most common one. Any child with nephrolithiasis requires a careful metabolic evaluation, including blood tests, urinalysis, and, in many cases, molecular diagnosis. This narrative review presents the epidemiology, pathophysiology, and diagnostic process in children with nephrolithiasis. Special emphasis is put on pathophysiological pathways leading to metabolic kidney stone disease and metabolic diagnostic steps in children with urolithiasis, as metabolic disturbances are the most common cause of recurrent urolithiasis in Europe and North America. Nephrolithiasis should be treated as a symptom of renal or systemic disorders, and in every child, the cause of these disorders should be sought to prevent recurrence.