title: Comparison of food allergy prevalence among Chinese infants in Chongqing, 2009 versus 1999.
abstract: BACKGROUND
  Food allergy prevalence is increasing in developed countries, but these results have not yet been verified in developing countries, especially in China. Our aim was to determine whether the prevalence and characteristics of food allergy have changed over the last 10 years in Chongqing, China.
  
  
  METHODS
  Two cross-sectional studies were performed, 10 years apart (1999 and 2009) using the same diagnostic methods in the same age group (0-24 months) of the same clinic in Chongqing, China. A total of 401 infants were randomly selected for the present study. Food allergy was confirmed by food challenge. spss 15.0 was used to analyze the difference in prevalence.
  
  
  RESULTS
  Food allergy prevalence increased significantly from 3.5% in 1999 to 7.7% in 2009 (P= 0.017). The prevalence of a positive skin-prick-test response was also increased (from 9.9% to 18%; P= 0.002). Egg and cow's milk were still the most common food allergens, which cause skin and gastrointestinal symptoms in most infants.
  
  
  CONCLUSIONS
  This is the first study in China to indicate time trends in food allergy prevalence and characteristics. Our data show that in the 10-year period from 1999 to 2009, the prevalence of food allergy seems to have increased in China.
authors.affiliation: Department of Pediatrics, Division of Primary Child Care, Children's Hospital, Chongqing Medical University, Yuzhong District, Chongqing, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Hu
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
authors.forename: Haiqi
authors.initials: H
authors.lastname: Li
mesh_terms: D017677:Age Distribution; D001942:Breast Feeding; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D004531:Eggs / Q000009:adverse effects; D005260:Female; D005512:Food Hypersensitivity / Q000175:diagnosis / Q000453:epidemiology* / Q000276:immunology*; D006801:Humans; D007223:Infant; D007225:Infant Food / Q000009:adverse effects; D041943:Infant Formula; D007231:Infant, Newborn; D008297:Male; D016269:Milk Hypersensitivity / Q000453:epidemiology; D015995:Prevalence; D017678:Sex Distribution; D012882:Skin Tests; D013997:Time Factors