title: Prevalence and severity of asthma and allergies in schoolchildren in Lhasa, Tibet.
abstract: BACKGROUND
  The International Study of Asthma and Allergies in Childhood (ISAAC) demonstrated that large variations existed in the prevalence of symptoms of asthma, allergic rhinoconjunctivitis and eczema throughout the world and that environmental factors and lifestyle customs are major determinants of the prevalence and severity of these diseases. However, the relevant data about children living at high-altitude locations were considered to be underreported.
  
  
  OBJECTIVE
  The ISAAC Phase III programme was carried out in Lhasa, the Tibetan Autonomous Region in China, at an elevation of 3658 m above sea level to examine the occurrence of asthma, allergic rhinoconjunctivitis and eczema in schoolchildren aged 13-14 years.
  
  
  METHODS
  All 3196 schoolchildren in eight public junior high schools in urban Lhasa who were confirmed to be 13-14 years old were invited and participated in both written and video questionnaire investigations, among which 3190 pieces of data (49.8% of boys and 50.2% of girls) were validated and analysed.
  
  
  RESULTS
  Among the overall observations, the prevalence of 'having ever experienced wheezing', 'current wheezing' and 'diagnosed to have asthma' was 1.4%, 0.8% and 1.1%, respectively. The prevalence of current exercise-induced asthma and current nocturnal cough was 7.1% and 4.6%, respectively. The current prevalence of allergic rhinoconjunctivitis and eczema was 5.2% and 0.4%, respectively. In addition, the prevalence of rhinoconjunctivitis symptoms during the past 12 months showed no discernable differences throughout the year.
  
  
  CONCLUSIONS
  The prevalence of asthma, allergic rhinoconjunctivitis and eczema over the past 12 months was the lowest among the centres, that performed ISAAC worldwide.
authors.affiliation: Department of Medicine, Shinshu University School of Medicine, Matsumoto, Japan. ydzmyp@hotmail.com
authors.forename: Y
authors.initials: Y
authors.lastname: Droma
authors.forename: O
authors.initials: O
authors.lastname: Kunii
authors.forename: Y
authors.initials: Y
authors.lastname: Yangzom
authors.forename: M
authors.initials: M
authors.lastname: Shan
authors.forename: L
authors.initials: L
authors.lastname: Pingzo
authors.forename: P
authors.initials: P
authors.lastname: Song
mesh_terms: D000293:Adolescent; D000531:Altitude; D001249:Asthma / Q000453:epidemiology*; D003233:Conjunctivitis, Allergic / Q000453:epidemiology*; D004485:Eczema / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D015995:Prevalence; D012221:Rhinitis, Allergic, Perennial / Q000453:epidemiology*; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D018609:Tibet / Q000453:epidemiology; D014505:Urban Population