title: Dissociation between the prevalence of atopy and allergic disease in rural China among children and adults.
abstract: BACKGROUND
  The prevalence of allergic diseases is increasing worldwide, but the reasons are not well understood. Previous studies suggest that this trend might be associated with lifestyle and urbanization.
  
  
  OBJECTIVE
  We sought to describe patterns of sensitization and allergic disease in an unselected agricultural Chinese population.
  
  
  METHODS
  The data were derived from a community-based twin study in Anqing, China. Skin prick tests were performed to foods and aeroallergens. Atopy was defined as sensitization to 1 or more allergens. Allergic disease was ascertained by means of self-report. The analysis was stratified by sex and age (children [11-17 years] and adults [>or=18 years]) and included 1059 same-sex twin pairs.
  
  
  RESULTS
  Of 2118 subjects, 57.6% were male (n = 1220). Ages ranged from 11 to 71 years, and 43.3% were children (n = 918). Atopy was observed in 47.2% (n = 999) of participants. The most common sensitizing foods were shellfish (16.7%) and peanut (12.3%). The most common sensitizing aeroallergens were dust mite (30.6%) and cockroach (25.2%). Birth order and zygosity had no effect on sensitization rates. Multivariate logistic regression models revealed that risk factors for sensitization include age for foods and sex for aeroallergens. The rates of food allergy and asthma were estimated to be less than 1%.
  
  
  CONCLUSIONS
  Atopic sensitization was common in this rural farming Chinese population, particularly to shellfish, peanut, dust mite, and cockroach. The prevalence of allergic disease, in contrast, was quite low.
authors.affiliation: Division of Allergy and Immunology, Children's Memorial Hospital, Chicago, IL, USA. jskim@childrensmemorial.org
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Kim
authors.forename: Fengxiu
authors.initials: F
authors.lastname: Ouyang
authors.forename: Jacqueline A
authors.initials: JA
authors.lastname: Pongracic
authors.forename: Yaping
authors.initials: Y
authors.lastname: Fang
authors.forename: Binyan
authors.initials: B
authors.lastname: Wang
authors.forename: Xue
authors.initials: X
authors.lastname: Liu
authors.forename: Houxun
authors.initials: H
authors.lastname: Xing
authors.forename: Deanna
authors.initials: D
authors.lastname: Caruso
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.forename: Shanchun
authors.initials: S
authors.lastname: Zhang
authors.forename: Xiping
authors.initials: X
authors.lastname: Xu
authors.forename: Xiaobin
authors.initials: X
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002681:China / Q000453:epidemiology; D004200:Diseases in Twins / Q000453:epidemiology; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000175:diagnosis / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012424:Rural Population; D012882:Skin Tests; D055815:Young Adult