[Nephrolithiasis in children].

We reevaluated the medical records of 112 children with urolithiasis. The prevalence of this condition was 1/4.500 children admitted to our hospital. The mean age was 8.2 years and 54.4% of the afflicted patients were males. Fifty percent of the patients studied had a family history of urolithiasis. The two most frequent etiologies were urinary tract infections and metabolic disorders (hypercalciuria states, distal renal tubular acidosis and cystinuria). The etiology of the urolithiasis was unknown in 15% of our patients. The levels of magnesium and citrate, inhibitors of crystallization, were moderately low in some of the cases in which it was determined. Fifty percent of the children with urolithiasis showed urinary or renal complications. The extracorporeal lithotripsy was an effective treatment of urolithiasis in the patients in which it was performed. The recurrence rate was 8%. In one third of the urolithiasis associated with urinary infections and/or urinary tract malformations we found chronic pyelonephritis.