title: Urinary stone composition in pediatric patients: a retrospective study of 205 cases.
abstract: BACKGROUND
  Stone composition has changed substantially over the past decades in developed countries. We studied urinary stone composition in Tunisian children.
  
  
  METHODS
  We studied 205 children ranging from 3 months to 16 years old age and who were diagnosed as having urinary stones (122 boys and 83 girls). Stone analysis was performed respectively using a stereomicroscope and by infrared spectroscopy to determine, respectively, the morphological type and molecular composition of each.
  
  
  RESULTS
  Of 205 stones analysed, 77 (37.5%) were composed of a single constituent. Calcium oxalate (CaOx) stone were predominant, being a constituent of 54.7% of stones, followed by calcium phosphate and purines; 14.6% of cases. Calcium oxalate monohydrate was more frequently seen in girls (p < 0.01), while struvite was more common in boys (p < 0.001). Teenagers were more affected by whewellite stones compared with infants (p < 0.05). Purine stones were predominant in 20% of cases, but its prevalence decreased with age.
  
  
  CONCLUSIONS
  The increase in calcium oxalate stones in school age children and the decrease of struvite and purines stones confirm the change in the etiology of urolithiasis with respect to age.
authors.affiliation: Department of Biochemistry and Toxicology, University Hospital, Monastir, Tunisia. akram_alaya@yahoo.co.uk
authors.forename: Akram
authors.initials: A
authors.lastname: Alaya
authors.forename: Abdellatif
authors.initials: A
authors.lastname: Nouri
authors.forename: Mohamed Fadhel
authors.initials: MF
authors.lastname: Najjar
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000818:Animals; D002648:Child; D002675:Child, Preschool; D004032:Diet; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D012189:Retrospective Studies; D012737:Sex Factors; D014545:Urinary Calculi / Q000737:chemistry*