Epidemiological survey of allergic diseases in first-year junior high school students in Wakayama Prefecture in 2003

摘要

Allergic diseases have been increasing in prevalence in developed countries, including Japan. The aim of the present report was to determine the prevalence of allergies in Wakayama prefecture using an epidemiological study. In total, 759 first-year students attending junior high school in Hidaka country, Wakayama prefecture, were surveyed. The results for 699 cases were then analyzed. A questionnaire regarding allergic diseases, specific IgE measurements performed using a MAST26 system (Hitachi Co., Ltd.), and total serum IgE levels measured using RIST (Pharmacia Co., Ltd.) were performed. The prevalence (present + past) of various allergic diseases was 37.9%. The prevalence of rhinitis, including pollinosis, was 31.0%, while that of atopic dermatitis was 26.2% and bronchial asthma was 11.3%. The positive rates for specific IgE antibodies against Japanese cedar pollen was 48.6%. The positive rate for Dermatophagoides farinae, timothy and housedust II were 44.2%, 29.6%, and 28.9%, respectively. Statistically significant differences were recognized between the students with allergic rhinitis, atopic dermatitis, allergic conjunctivitis or bronchial asthma and positive results for D. farinae, housedust II, cedar pollen, Penicillium, Cladosporium, or Aspergillus-specific antibodies. Regarding family history (two generations), a statistical significant difference between family history and positivity for specific IgE antibodies like D. farinae, housedust II, ragweed, cedar pollen or Cladosporium was observed. The total IgE titer was correlated with the number of positive allergen items. The increasing prevalence of various allergic diseases in developed countries remains a mystery, but the hygienehypothesis has attracted some attention. The findings of this epidemiologic study will contribute to basic data on the increasing prevalence of various allergic diseases.