title: Worldwide variations in the prevalence of symptoms of atopic eczema in the International Study of Asthma and Allergies in Childhood.
abstract: BACKGROUND
  Little is known about the prevalence of atopic eczema outside Northern Europe.
  
  
  OBJECTIVE
  We sought to describe the magnitude and variation in the prevalence of atopic eczema symptoms throughout the world.
  
  
  METHODS
  A cross-sectional questionnaire survey was conducted on random samples of schoolchildren aged 6 to 7 years and 13 to 14 years from centers in 56 countries throughout the world. Those children with a positive response to being questioned about the presence of an itchy relapsing skin rash in the last 12 months that had affected their skin creases were considered to have atopic eczema. Children whose atopic eczema symptoms resulted in sleep disturbance for 1 or more nights per week were considered to have severe atopic eczema.
  
  
  RESULTS
  Complete data was available for 256,410 children aged 6 to 7 years in 90 centers and 458,623 children aged 13 to 14 years in 153 centers. The prevalence range for symptoms of atopic eczema was from less than 2% in Iran to over 16% in Japan and Sweden in the 6 to 7 year age range and less than 1% in Albania to over 17% in Nigeria for the 13 to 14 year age range. Higher prevalences of atopic eczema symptoms were reported in Australasia and Northern Europe, and lower prevalences were reported in Eastern and Central Europe and Asia. Similar patterns were seen for symptoms of severe atopic eczema.
  
  
  CONCLUSIONS
  Atopic eczema is a common health problem for children and adolescents throughout the world. Symptoms of atopic eczema exhibit wide variations in prevalence both within and between countries inhabited by similar ethnic groups, suggesting that environmental factors may be critical in determining disease expression. Studies that include objective skin examinations are required to confirm these findings.
authors.affiliation: Queen's Medical Centre, University Hospital, Nottingham, United Kingdom.
authors.forename: H
authors.initials: H
authors.lastname: Williams
authors.forename: C
authors.initials: C
authors.lastname: Robertson
authors.forename: A
authors.initials: A
authors.lastname: Stewart
authors.forename: N
authors.initials: N
authors.lastname: Aït-Khaled
authors.forename: G
authors.initials: G
authors.lastname: Anabwani
authors.forename: R
authors.initials: R
authors.lastname: Anderson
authors.forename: I
authors.initials: I
authors.lastname: Asher
authors.forename: R
authors.initials: R
authors.lastname: Beasley
authors.forename: B
authors.initials: B
authors.lastname: Björkstén
authors.forename: M
authors.initials: M
authors.lastname: Burr
authors.forename: T
authors.initials: T
authors.lastname: Clayton
authors.forename: J
authors.initials: J
authors.lastname: Crane
authors.forename: P
authors.initials: P
authors.lastname: Ellwood
authors.forename: U
authors.initials: U
authors.lastname: Keil
authors.forename: C
authors.initials: C
authors.lastname: Lai
authors.forename: J
authors.initials: J
authors.lastname: Mallol
authors.forename: F
authors.initials: F
authors.lastname: Martinez
authors.forename: E
authors.initials: E
authors.lastname: Mitchell
authors.forename: S
authors.initials: S
authors.lastname: Montefort
authors.forename: N
authors.initials: N
authors.lastname: Pearce
authors.forename: J
authors.initials: J
authors.lastname: Shah
authors.forename: B
authors.initials: B
authors.lastname: Sibbald
authors.forename: D
authors.initials: D
authors.lastname: Strachan
authors.forename: E
authors.initials: E
authors.lastname: von Mutius
authors.forename: S K
authors.initials: SK
authors.lastname: Weiland
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000453:epidemiology*; D002648:Child; D003876:Dermatitis, Atopic / Q000453:epidemiology*; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000453:epidemiology*; D008297:Male; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires