How new guidelines have influenced the development of IgE-mediated food allergies

02.2026
Author Dr. Martin Claßen, Bremen

IgE-mediated food protein allergies are the most frequent cause of anaphylaxis and must therefore be avoided at all costs. After years of attempting to prevent sensitisation to allergens by avoiding them for long periods, it became clear that this strategy was not successful (in part because sensitisation by other means, e.g. via the skin, could not be avoided). The LEAP study1 has shown that infants should be fed allergens – even potent allergens such as peanuts – orally at an early stage.

As a result of these findings, the guidelines in the USA on introducing peanuts have been updated. From 2015 they applied to children with atopic dermatitis or egg allergy, from 2017 to children with a moderate risk, and from 2021 to all babies regardless of their food allergy risk profile.

The extent to which this had an impact on incidence rates of allergies was previously unclear. The study presented here used registry data from 31 practices in various places in the USA to find children with food allergies, particularly peanut allergies, and atopic dermatitis. Three cohorts were chosen: the first with children born before the guidelines were updated (“pre-guideline”), the second born between 2015 and 2017 (“post-guideline”) and the third born after the guidelines were expanded (“post-addendum”).

The first group contained 38,594 children, the second group contained 46,680 children and the third group contained 39,594 children. Most of the children in the first two groups were monitored for 2 years, while the children in the third group could by nature only be observed for 1 year. The incidence rate of peanut allergies was 0.79% in the pre-guideline group, 0.53% in the post-guideline group and 0.49% in the post-addendum group. There were also lower incidence rates of other food allergies (egg, cow’s milk, tree nuts, etc.) in the two groups where children were given allergens earlier. In children manifesting atopic dermatitis, the difference was less significant.

Comment: The results of the study referenced here provide more clear evidence that the intestine is the organ where tolerance to external allergens can be learnt. There can no longer be any doubt that children should be given allergens, no matter how potent, orally from an early age and then on a regular basis in their complementary food. This approach is safe, extremely effective and independent of individual risk. The results of the study also show the influence of atopic dermatitis on the risk of sensitisation.

Interestingly, the data indicates that guidelines have an effect on incidence rates of illness, provided that medical staff modify how they treat patients. However, this study does not review whether the new guidelines have been adopted comprehensively. 
As incidence rates of peanut allergies are lower in Central Europe than in the USA, the effect on peanut allergies here is bound to be lower. On the other hand, the principles also apply to other dietary proteins – so a wide range of food allergens, including potent ones, should similarly be included in the early stages of introducing children to complementary food here in Germany.

1Du Toit G, Sayre PH, Roberts G et al; Immune Tolerance Network LEAP-On Study Team. Effect of Avoidance on Peanut Allergy after Early Peanut Consumption. N Engl J Med. 2016;374(15):1435–1443. DOI: 10.1056/NEJMoa1514209

Reference:
Gabryszewski SJ, Dudley J, Faerber JA et al. Guidelines for Early Food Introduction and Patterns of Food Allergy. Pediatrics November 2025; 156(5): e2024070516. DOI: 10.1542/peds.2024-070516