Food Allergy Risk Changes as Children Grow

Sensitization to major food allergens changes during the first five years of life, as shown by a large birth-cohort study involving Karl Landsteiner University.

Krems (Austria), 14. October 2026 – Sensitization to food allergens can change considerably during the first five years of a child’s life. A large Canadian birth-cohort study shows that sensitization to peanut often develops early and persists, while sensitization to several tree nuts tends to appear later. Some children also lose sensitization to allergen components associated with systemic allergic reactions. Researchers from Karl Landsteiner University (klu Krems) played a key role in the international study. By following children over several years rather than testing them at a single point in time, the researchers were able to trace how sensitization develops in early childhood. Their findings could help doctors and families make better-informed decisions about prevention, diagnosis and treatment.

Food allergy is an important health concern in childhood, and knowing whether an allergy is likely to persist or disappear can affect medical decisions. Sensitization, however, is not the same as an allergy: specific IgE antibodies may be detectable without a child developing symptoms after eating the food concerned. Detailed data on how such sensitization changes during early childhood have so far been scarce for North America. The study, with major contributions from the Department of Pediatric and Adolescent Medicine at University Hospital St. Pölten, a teaching and research site of klu Krems, set out to examine these changes over time.

Allergies in Motion

“Especially in young children, a positive allergy test is not necessarily the end of the story,” says Prof. Thomas Eiwegger, Head of the Department of Pediatric and Adolescent Medicine at University Hospital St. Pölten. “We need to know whether a sensitization persists, disappears or develops later. Looking at individual allergen components gives us valuable information for discussing risks and treatment options with families.”

The researchers analysed samples from 500 mother-child pairs taking part in the Canadian CHILD Study, working with colleagues from leading Canadian universities and pediatric research centres. Blood samples were available from the mothers during pregnancy and from their children at one and five years of age. Around 300 individual allergen extracts and components were tested. At age one, specific IgE sensitization was found in 25.3% of the children; by age five, this had risen to 40.4%. The allergens involved changed as well. Egg and peanut were among the main food sensitizers at age one, while peanut and tree nuts predominated at age five. Sensitization to environmental allergens such as cats, dogs, house dust mites and grass pollen also became more common.

Peanut and tree nuts showed notably different patterns. Around half of the children with sensitization to major peanut components already showed it at twelve months and remained sensitized at age five. Important components of cashew, hazelnut, walnut and pistachio, by contrast, were often recognized only later. Sensitization was not always permanent: around one in four children lost sensitization to important 2S albumins during the four-year period. These proteins include major allergen components of peanut, tree nuts and sesame and are useful markers for food allergies associated with systemic reactions.

Therapy with Knowledge

These changes are particularly relevant as treatments for food allergies develop. Oral immunotherapy is now included in treatment guidelines and appears to work particularly well when started early. Knowing whether a sensitization is new, persistent or disappearing can therefore be useful when doctors and families discuss treatment. The authors also point to an important limitation: the study did not include oral food challenges to confirm clinical food allergy. Its findings concern sensitization and do not mean that one in four children outgrow an established food allergy.

The work also builds on expertise in pediatric allergology at klu Krems and University Hospital St. Pölten. Before moving to St. Pölten, Eiwegger established a clinical research program for allergy and anaphylaxis at Toronto’s Hospital for Sick Children, where he worked in patient care, research and teaching. This experience now contributes to the pediatric immunology and allergology focus at klu Krems, linking clinical care with research and advanced allergy diagnostics.

Image available on request.

Original publication:
IgE Sensitization Patterns of Mothers and Their Offspring in the First Five Years of Life The CHILD Study. M.A.A. Kodydek: M.E. Reyna: A. Kothari: M. Monteiro: J.A. Hoang: K.E. San Diego: A. Dubeau: L. Hung: X. Yin: E. Simons: S.E. Turvey: P.J. Mandhane: P. Subbarao: T.J. Moraes: T. Eiwegger. Allergy (2026). doi: 10.1111/all.70516.

<fc>IgE</fc> Sensitization Patterns of Mothers and Their Offspring in the First Five Years of Life The <fc>CHILD</fc> Study – Kodydek – Allergy – Wiley Online Library

Karl Landsteiner University (10/2026)

The Karl Landsteiner University (klu Krems) is an internationally recognized educational and research institution on the Campus Krems. The klu Krems offers modern, demand-oriented education and continuing education in medicine and psychology as well as PhD programmes in the fields of mental health and neuroscience, and Tumour Biology. The flexible educational programme is tailored to the needs of students, the requirements of the labour market and the challenges of science. With its university hospitals in Krems, St. Pölten and Tulln, as well as the MedAustron Ion Therapy and Research Centre in Wiener Neustadt, the university provides clinical teaching and research of an international standard. In its research, klu Krems focuses on interdisciplinary areas of high social and health policy relevance, including mental health, neuroscience, oncology, and issues relating to water quality and its impact on health. The university was founded in 2012 and accredited in 2013 by the Agency for Quality Assurance and Accreditation Austria (AQ Austria). Its founding institutions include the Medical University of Vienna, the Vienna University of Technology and the Province of Lower Austria. https://www.kl.ac.at/en

Scientific Contact

Prim. Univ.-Prof. PD Dr. Thomas Eiwegger

Dept. of Pediatric and Adolescent Medicine, University Hospital St. Pölten

Karl Landsteiner University

Dunant-Platz 1

3100 St. Pölten / Austria

M +43 676 858 10 31740

E thomas.eiwegger@stpoelten.lknoe.at

E thomas.eiwegger@kl.ac.at

Karl Landsteiner University

Mag. Selma Vrazalica, BA

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