Environmental allergens and morbidity in atopic and non-atopic families

148 newborns of non-atopic and 329 newborns of atopic parents were included in a five-year follow-up study of atopic diseases. The prevalence of atopic diseases at five years of age is compared to environmental factors, which may be involved in the development of atopic diseases. There was no significant correlation between the development of atopic disease and the following factors: the nature of the immediate environment (industrial, agricultural, rural, urban, arboreal, lake-district); building materials, heating systems and general state of repair of the houses, including its interior decoration; the presence of pets, plants, humidifiers or cigarette smoke. There was, however, one exception: in both family groups the avoidance of woollen garments and bed clothes before the outbreak of atopic symptoms was associated with the increased prevalence of asthma, allergic rhinitis and atopic dermatitis. The cause of this association remained uncertain. Children with atopic diathesis are known to frequently display skin intolerance to wool. Therefore, wool avoidance in a family may only indicate that the child was potentially atopic. Atopic children suffered from ear infections and vomiting more often than control children. The incidence of ear infections was also increased amongst children with a positive family history of atopy, even if no atopic disease was diagnosed in the child himself. Although breast fed infants tended to have less infectious diseases than those weaned early, ear infections were equally common in all feeding groups. This is further evidence, that in part of the cases of recurrent ear infections, atopy should be considered as a possible etiologic factor.