RT Journal Article SR Electronic T1 Early allergen exposure, skin prick responses, and atopic wheeze at age 5 in English children: a cohort study JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP 855 OP 861 DO 10.1136/thx.2003.019877 VO 59 IS 10 A1 P Cullinan A1 S J MacNeill A1 J M Harris A1 S Moffat A1 C White A1 P Mills A1 A J Newman Taylor YR 2004 UL http://thorax.bmj.com/content/59/10/855.abstract AB Background: For many years it has been assumed that the risk of childhood respiratory allergies is related to allergen exposures in early life. There are, however, few prospective data in support. We aimed to examine this relationship in a representative cohort of children born in Ashford, Kent (UK). Methods: 625 children (94% of those eligible) were followed from birth to the age of 5.5 years at which time 552 underwent skin prick testing to extracts of house dust mite and cat fur allergens. Maternal reports of wheeze in the last year were collected by interview. These outcomes were related to individual domestic concentrations of Der p 1 and Fel d I allergens estimated from dust collection at the age of 8 weeks. Results: 10% of children were sensitised to house dust mite or cat at age 5.5 years; 7% had atopic wheeze. No significant relationships between allergen exposure and either sensitisation or wheeze were found but, on examination, the exposure-response relationships for both allergens and for each outcome rose steeply at low levels of exposure and were attenuated at high levels of exposure. These patterns were modified by paternal atopy and by birth order. Conclusions: There are no linear relationships between early allergen exposure and the induction of childhood respiratory allergy; rather, the risks of IgE sensitisation and asthma rise at very low levels of exposure and are attenuated thereafter. These patterns are influenced by parental atopy and birth order. These findings suggest important gene-environment interactions in the development of atopy and asthma and imply that reductions in domestic allergen exposure alone are unlikely to have a major impact in decreasing the incidence of these diseases in childhood.