How common is food allergy across Europe?
Published online: March 18, 2019
A significant part of the European population reports symptoms related to food. Of adults across Europe, it has been estimated that 2-37% have a self-reported food allergy (FA) to any food, and 1-19% perceives a FA to frequently consumed and commonly implicated foods. Data on the prevalence of clinically confirmed FA are scarcer, and the use of varied study protocols in different research centers and countries hinder accurate comparisons of prevalence.
In a recent study published in The Journal of Allergy and Clinical Immunology: In Practice, Lyons et al. set out to determine the prevalence of probable FA (reported symptoms to a specific food combined with specific IgE-antibodies to the same food in the blood) and of food challenge-confirmed FA in adults across Europe. Data collected during the standardized pan-European food allergy studies (in the EuroPrevall project) were evaluated. In phase I, a random sample of the general adult population in eight European centers was approached with a short screening questionnaire. Phase II consisted of a more extensive questionnaire on reactions to 24 pre-selected commonly implicated foods, and measurement of specific IgE against these foods (hen’s egg, cow’s milk, fish, shrimp, peanut, hazelnut, walnut, peach, apple, kiwi, melon, banana, tomato, celery, carrot, corn, lentils, soy, wheat, buckwheat, sesame seed, mustard seed, sunflower seed, and poppy seed). In phase III, subjects with probable FA were invited for double-blind placebo-controlled food challenge.
Analyses revealed that overall prevalence of probable FA was highest in Zurich at 5.6%, followed by 3.3% in Madrid, 2.8% in Lodz, 2.1% in Utrecht, 1.4% in Reykjavik and 0.3% in Athens. Oral allergy symptoms were reported most frequently (81.6%), then skin symptoms (38.2%) and rhino-conjunctivitis (29.5%). In Zurich, Lodz and Utrecht, the highest prevalence of probable FA was found for hazelnut, peach, and apple. Peach was also one of the top three causative foods in Madrid, along with melon and shrimp; and in Athens, along with walnut and sunflower seed. In Reykjavik, the highest prevalence estimates were found for banana, carrot and shrimp. Of the 55 food challenges performed, most were conducted with hazelnut, peach and apple; and 40 (72.8%) were classified as positive.
In summary, FA shows substantial geographical variation in prevalence and causative foods in adults across Europe. Clinically confirmed FA was found to be much less common than self-reported FA, but prevalence of probable FA still reached almost 6% in parts of Europe.The large gap between prevalence of self-reported and of clinically confirmed FA emphasizes the importance of accurate diagnosis. Plant foods, such as apple, hazelnut, and peach, dominated as most common causative foods, with the exception of shrimp in Spain and Iceland. As allergies to plant foods are commonly pollen-related, and the consumption of shrimp in Spain and Iceland is high, these findings suggest that occurrence of FA is likely related to pollen exposure and possibly to consumption.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.