A differing pattern of association between dietary fish and allergen-specific subgroups of atopy

Background: We examined the role of fish intake in the development of atopic disease with particular reference to the possibility of differential effects on allergen-specific subgroups of sensitization. Methods: The exposure of interest was parental report of fish intake by children aged 8 years at the 1997 Childhood Allergy and Respiratory Health Study (n = 499). The outcomes of interest were subgroups of atopy: house dust mite (HDM)-pure sensitization [a positive skin-prick test (SPT) ≥2 mm to Der p or Der f only], ryegrass-pure sensitization (a positive SPT ≥2 mm to ryegrass only); asthma and hay fever by allergen-specific sensitization. Results: A significant association between fish intake and ryegrass-pure [adjusted odds ratio (AOR) 0.37 (0.15-0.90)] but not HDM-pure sensitization [AOR 0.87 (0.36-2.13)] was found. Fish consumption significantly decreased the risk for ryegrass-pure sensitization in comparison with HDM-pure sensitization [AOR 0.20 (0.05-0.79)]. Conclusions: We have demonstrated a differential effect of fish intake for sensitization to different aeroallergens. This may be due to the different timing of allergen exposure during early life. Further investigation of the causes of atopic disease should take into account allergen-specific subgroups.