title: [Breath tests in children with suspected lactose intolerance].
abstract: BACKGROUND
  Up to 70% of the world population is lactose intolerance. However, there are no epidemiological studies among Chilean pediatric population affected by this condition.
  
  
  OBJECTIVE
  Clinical characterization of a series of children who underwent the lactose intolerance breath test for lactose intolerance study, establishing intolerance and malabsorption frequencies, the most frequent symptoms, and test performance depending on the origin.
  
  
  METHODS
  Patients under 18 years old who took the lactose intolerance breath test in the Gastroenterology Laboratory of the Catholic University of Chile, and who were admitted due to clinically suspected lactose intolerance. Malabsorption was considered when there was as an increase of ≥20ppm above the baseline (H2) or ≥34ppm of H2 and methane (CH4) combined. Intolerance was considered when the above was associated with a symptom intensity score ≥7 during registration.
  
  
  RESULTS
  The analysis included194 patients aged 1 to17 years of age. Of these, 102 (53%) presented with malabsorption, and 53 (27%) were intolerant. The frequency of lactose intolerance varied from 7.1 to 45.4%, and it occurred more frequently at older ages. The most common reported symptoms were abdominal pain, bloating and rumbling.
  
  
  CONCLUSIONS
  Lactose malabsorption and intolerance can be investigated from the first years of life using the lactose breath test plus a symptom questionnaire. An increase in the frequency of intolerance with age, and a greater number of positive tests, if they were requested by a gastroenterologist, were observed.
authors.affiliation: Estudiantes de Pregrado, Facultad de Medicina, Pontificia Universidad Católica de Chile.
authors.forename: P Ángela
authors.initials: PÁ
authors.lastname: Parra
authors.affiliation: Estudiantes de Pregrado, Facultad de Medicina, Pontificia Universidad Católica de Chile.
authors.forename: C Simone
authors.initials: CS
authors.lastname: Furió
authors.affiliation: Gastroenterólogo Infantil, Pontificia Universidad Católica de Chile. Electronic address: sarancib@med.puc.cl.
authors.forename: A Gabriel
authors.initials: AG
authors.lastname: Arancibia
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001944:Breath Tests; D002648:Child; D002675:Child, Preschool; D002677:Chile / Q000453:epidemiology; D005260:Female; D006801:Humans; D006859:Hydrogen / Q000032:analysis*; D007223:Infant; D007787:Lactose Intolerance / Q000175:diagnosis* / Q000453:epidemiology; D008297:Male; D008697:Methane / Q000032:analysis*; D011795:Surveys and Questionnaires
chemical_list: D006859:Hydrogen; D008697:Methane
keywords: Breath Test; Lactosa; Lactose; Lactose Intolerance; Malabsorption; intolerancia a la lactosa; malabsorción; test de aire espirado