title: Prevalence of Japanese cedar pollinosis among schoolchildren in Japan.
abstract: BACKGROUND
  Japanese cedar pollinosis is an important allergic rhinoconjunctivitis in Japan in spring. We investigated the relationship between the amount of pollen in the air and the prevalence of the disease and sensitization to Japanese cedar pollen in this ecological study.
  
  
  METHODS
  The IgE antibody to Japanese cedar pollen (JCP-IgE) was determined in human serum and rhinoconjunctival symptoms were surveyed in 407-510 children in May or June every year from 1995 to 2001. Japanese cedar pollinosis was defined as being JCP-IgE >or=1.5 IU/ml and having any rhinoconjunctival symptom lasting 3 weeks or longer in March or April.
  
  
  RESULTS
  Prevalence rates of Japanese cedar pollinosis were 13.8-22.9%. Prevalence rates of being JCP-IgE >or=1.5 IU/ml were 39.0-50.1%, and those of being JCP-IgE >or=15.01 IU/ml were 11.4-23.2%. All prevalence rates were significantly related to the amount of pollen in the air. The proportion of subjects with rhinoconjunctival symptoms was relatively constant in each stratum of low JCP-IgE levels (<0.35, 1.50-2.99, 3.0-14.9 IU/ml).
  
  
  CONCLUSIONS
  High exposure to Japanese cedar pollen was associated with higher levels of JCP-IgE antibody and a high prevalence of Japanese cedar pollinosis. The relationship between the level of JCP-IgE and the proportion of subjects with symptoms was relatively constant.
authors.affiliation: Department of Social Medicine and Cultural Sciences, Research Institute for Neurological Diseases and Geriatrics, Kyoto, Japan. kozasa@basic.kpu-m.ac.jp
authors.forename: Kotaro
authors.initials: K
authors.lastname: Ozasa
authors.forename: Kenji
authors.initials: K
authors.lastname: Dejima
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takenaka
mesh_terms: D028203:Cedrus / Q000276:immunology; D002648:Child; D003233:Conjunctivitis, Allergic / Q000453:epidemiology* / Q000276:immunology; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D007564:Japan / Q000453:epidemiology; D011058:Pollen / Q000276:immunology; D015995:Prevalence; D006255:Rhinitis, Allergic, Seasonal / Q000453:epidemiology* / Q000276:immunology; D011795:Surveys and Questionnaires
chemical_list: D007073:Immunoglobulin E