[Respiratory atopy and season of birth: epidemiologic considerations]

Abstract

Numerous environmental conditions have been considered factors which may favour atopic disease. 320 children (233 males and 87 females, aged from 1 year and 10 months to 16 years and 6 months) were followed at the Out-patients' Department for Allergology of the V Pediatric Clinic (University of Milano). These children were examined in order to determine possible environmental factors, which could be related to subsequent allergic sensitization in infancy. We excluded all the subjects with a high atopic risk owing to: gestational age under 36 weeks, weight at birth under 2,500 Kg, respiratory distress in infancy, bronchiolitis in the first 6 months of life, particularly unfavourable conditions of the domestic microclimate. We did not find any correlation between the length of the period of breast feeding alone and the subsequent appearance of atopic sensitization. The only factor which could be related to atopic sensitization was the season of birth: the majority of atopic subjects were born in the period of maximum exposure to their respective allergens. Our data underline the difficulty in planning any efficacious prophylactic measure against respiratory allergy, limiting our possibilities to the improvement of assistance during pregnancy and to newborns and to the realization of better hygienic and environmental conditions.