Unexpected allergic reactions to food in adult patients with peanut or hazelnut allergy: an explorative study

Abstract

Title: Unexpected allergic reactions to food in adult patients with hazelnut or peanut allergy: an explorative study. Background: There is lack of knowledge about the prevalence, incidence, severity and causes of unexpected allergic reactions to food in adult. Previous studies are often carried out in mixed populations, with a qualitative and/or retrospective design. Aim and research question(s): Contribute to improvement of information from health care professionals, and food safety to reduce the number of allergic reactions. The abbreviated research question was: what is the period prevalence, incidence, severity and causes of unexpected allergic reactions to food in peanut and/or hazelnut allergic adults? Method: A quantitative, explorative study, with a retrospective and longitudinal, prospective part. Peanut and hazelnut allergic adults were non-random recruited from a Dutch academic hospital. Data collection took place between January and June 2012. The main study parameter was period prevalence. Two questionnaires were used for retrospective data collection. One questionnaire was used for prospective data collection, during a longitudinal period of 8-12 weeks. Parameters were analysed with descriptive and univariate analyses. Results: Thirty-four participants were included. The 5-year period prevalence was in 52%, > 10 reactions. The person time incidence rate was 0.17 reactions per person-month. Of the retrospective reported reactions, 30% was severe. Causes were prepackaged/fresh products (46%), constituted dishes at home (2%) and constituted dishes outside the home (30%). Of the prospective reported reactions on prepackaged products (n=7), three participants read the label. Conclusion: Peanut and hazelnut allergic adults often experience allergic reaction, whereof almost a third is severe. Reactions on constituted dishes mostly occur outside the home. There are food labelling and attitude issues, for example not every label mentions all allergens and not every patient reads labelling. Recommendations: Improve information from health care professionals about management of food allergy and prevention of allergic reactions. Improve food safety, e.g. improving food labelling and knowledge about food allergy in public eating places.