Trends in sensitisation to aero and food allergens: comparison between different birth cohorts

RATIONALE: This study provides information on changes in sensitisation rates in children on the Isle of Wight. METHODS: Three cohorts of children were recruited and underwent skin prick tests to a predefined panel of allergens (milk, egg, peanut, cod, house dust mite, cat and grass) by standard methodology. Wheat sensitisation was not analysed for Groups C and D due to different solutions used. Group A: Children born 1989, tested at four years (1993). Group B: Children born 2001/02, tested at three years (2004/05). Group C: Children born 1989, tested at ten years (1999). Group D: Children born in 1991/92, tested at 11 years (2002). RESULTS: Sensitisation to predefined food allergens increased significantly from 1.8% in 1993 (Group A) to 4.2% in 2004 (Group B) (p = 0.008). When wheat-grass cross-reactors were excluded, increase was no longer significant (p = 0.31). In contrast sensitisation to aeroallergens showed a significant decrease from 14.8% to 10.9% (p = 0.006). Notable decreases were seen in HDM (p = 0.006), and grass, (p = 0.013). A significant rise, from 2.2% in 1999 (Group C) to 4.6% in 2002 (Group D), was observed in sensitisation to food allergens (p = 0.008). Sensitivity to peanut (p = 0.1023) and grass (p = 0.0115) rose significantly. CONCLUSION: Prevalence of sensitivity to both food and aeroallergens was seen to be greater amongst older children than younger children. Amongst younger children we found a significant reduction in prevalence of sensitisation to aeroallergens. Amongst older children we found a significant increase in prevalence of sensitisation to food allergens.