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Primary and pollen-associated hazelnut allergy in school-aged children in Germany: A birth cohort study
Sina M Erhard1, Johanna Bellach2, Songül Yürek2
1Institute for Social Medicine, Epidemiology and Health Economics, Charité - Universitätsmedizin Berlin, Berlin, Germany; Department of Pediatric Respiratory Medicine, Immunology and Critical Care Medicine - Universitätsmedizin Berlin, Berlin, Germany; Department of Neonatology, University Children's Hospital Mannheim, University of Heidelberg, Mannheim, Germany.
Insights
In children, hazelnut allergy symptoms are less common than sensitization. Physicians should consider this, especially with co-sensitization to birch pollen, to prevent unnecessary dietary changes.
Area of Science:
- Pediatric Allergy and Immunology
- Clinical Nutrition
- Epidemiology
Background:
- Primary hazelnut allergy is a significant cause of anaphylaxis in children.
- Limited population-based data exists on hazelnut allergy and its association with birch pollen allergy in pediatric populations.
- This study addresses the prevalence of primary and pollen-associated hazelnut allergy in school-aged children.
Purpose of the Study:
- To determine the prevalence of primary hazelnut allergy in children.
- To investigate the association between hazelnut allergy and birch pollen allergy.
- To analyze sensitization profiles to hazelnut and birch pollen in children.
Main Methods:
- A cohort of 1570 newborns in Berlin was recruited between 2005-2009.
- A school-age follow-up included web-based questionnaires and clinical evaluations with skin prick tests, IgE serum tests, and oral food challenges.
- Allergic sensitization was assessed in a subset of participants.
Main Results:
- 1.9% of children reported hazelnut-allergic symptoms, with half indicating primary hazelnut allergy.
- 11.6% of children reported birch pollen allergy symptoms, and 0.6% had both.
- Nearly 20% of assessed children were sensitized to hazelnut, the most common food allergen, with many also sensitized to birch pollen.
Conclusions:
- Reported hazelnut allergy symptoms in children are less frequent than sensitization.
- Physicians should differentiate between sensitization and clinical allergy to avoid unnecessary dietary restrictions.
- Co-sensitization to hazelnut and birch pollen requires careful consideration in clinical management.
Background:
Primary hazelnut allergy is a common cause of anaphylaxis in children, as compared to birch-pollen associated hazelnut allergy. Population-based data on hazelnut and concomitant birch-pollen allergy in children are lacking. We aimed to investigate the prevalence of primary and pollen-associated hazelnut allergy and sensitization profiles in school-aged children in Berlin, Germany.
Methods:
1570 newborn children were recruited in Berlin in 2005-2009. The school-age follow-up (2014-2017) was based on a standardized web-based parental questionnaire and clinical evaluation by a physician including skin prick tests, allergen specific immunoglobulin E serum tests and placebo-controlled double-blind oral food challenges, if indicated.
Results:
1004 children (63.9% response) participated in the school-age follow-up assessment (52.1% male). For 1.9% (n = 19, 95%-confidence interval 1.1%-2.9%) of children their parents reported hazelnut-allergic symptoms, for half of these to roasted hazelnut indicating primary hazelnut allergy. Symptoms of birch-pollen allergy were reported for 11.6% (n = 116 95%-CI 9.7%-13.7%) of the children. Both birch-pollen allergy and hazelnut allergy associated symptoms affected 0.6% (n = 6, 95%-CI 0.2%-1.3%) of children. Assessment of allergic sensitization was performed in 261 participants and showed that almost 20% of these children were sensitized to hazelnut, being the most frequent of all assessed food allergens, or birch-pollen, the majority to both.
Conclusions:
Based on parental reports hazelnut-allergic symptoms were far less common than sensitization to hazelnut. This needs to be considered by physicians to avoid unnecessary changes in diet due to sensitization profiles only, especially when there is a co-sensitization to hazelnut and birch-pollen.
