Allergic disorders in urban and rural populations.

The incidence of bronchial asthma, rhinitis and dermatoses was investigated using a questionnaire given to 9010 and 4284 subjects in urban and rural environments, respectively. The diagnoses initially obtained through the questionnaires were confirmed by an allergologist. Results showed that the incidence of allergic conditions among 4293 subjects living in a newly constructed residential area was 4.2% (group A), 2.8% among 4717 subjects living in detached houses (group B) and 2.6% in rural areas (group C). In children the incidence of allergic conditions was higher (group A-5.5, group B-4.2, group C-4.7) than in adults (A-3.6, B-2.2, C-1.7). A higher incidence was observed in boys (6.3) than in girls (4.7). In adult females the incidence was higher (3.3) than in males (1.6). The incidence of bronchial asthma per thousand subjects studied was: group A-7.2 cases; group B-3.1; and group C-2.5. The relative frequency of allergic conditions in each group follows: group A: bronchial asthma 17%, allergic rhinitis 2.7%, allergic dermatoses 78.0%; group B: 10.6%, 4.2%, 83.6% and group C: 10.7%, 4.9%, 73% respectively.