Uncorrected Proof J Kermanshah Univ Med Sci. 2022 June; 26(2):e127184. Published online 2022 July 26. doi: 10.5812/jkums-127184. Research Article A Demographics Analysis of IgE- and Non-IgE-mediated Food Allergies in Children Mohammad Norolahi 1 , Masoumeh Hematyar 2 , Rahman Pouyanfar 1 , Seyed Karen Hashemitari 3 and Sepideh Darougar 2, 4, * 1 Faculty of Medicine, Tehran Medical Sciences Branch, Islamic Azad University, Tehran, Iran 2 Department of Pediatrics, Faculty of Medicine, Tehran Medical Sciences Branch, Islamic Azad University, Tehran, Iran 3 Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran 4 Amir-al-Momenin Hospital, Tehran Medical Sciences Branch, Islamic Azad University, Tehran, Iran * Corresponding author: Department of Pediatrics, Faculty of Medicine, Tehran Medical Sciences Branch, Islamic Azad University, Tehran, Iran. Email: sepidehdarougar@yahoo.com Received 2022 April 24; Revised 2022 July 04; Accepted 2022 July 05. Abstract Background: There are three broad types of food allergies, including IgE-mediated reactions, non-IgE-mediated reactions, and mixed reactions. The onset of IgE-mediated food allergies is usually rapid and can sometimes lead to serious illness. Non-IgE- mediated and mixed types of food allergies can cause significant morbidity as a result of chronic disease. Objectives: This study aimed to compare various types of food allergies and discuss the basis of their different presentations. Methods: This study was conducted on children aged 2 - 12 years old with signs or symptoms of food allergy in the allergy clinics of Azad University Hospitals, Tehran, Iran, from January 2019 to January 2020. Food allergy was evaluated in these patients by careful history, physical exam, skin prick test, and atopy patch test. Results: A positive family history of atopy was detected in the first-degree relatives of 82 (63%) patients. All the children were exclu- sively breastfed at the beginning. A total of 61 patients had positive skin prick test (SPT), and 68 patients had positive atopy patch test (APT) results. Among food allergens, a significant correlation was detected between positive atopic patch test results and hy- persensitivity reactions to cow’s milk (P value = 0.001), beef (0.002), and tomato (0.04). There was the same significant correlation between positive skin prick test results, allergens, and wheat (P value = 0.01). Conclusions: Although skin prick and atopy patch tests may help identify the culprit foods, oral food challenges are the mainstay of the diagnosis. Keywords: Food Allergy, Skin Prick Test, Atopy Patch Test 1. Backgound The prevalence of food allergies has increased in re- cent decades. Since many factors, including patients’ age and genetics, environmental conditions, and dietary ex- posure may affect the prevalence of food allergy, accurate determination varies among nations. Due to the lack of understanding of food allergy by patients, it is quite dif- ficult to estimate its prevalence. However, World Allergy Organization has estimated that food allergy affects 2.5% of the general population (1). In addition, using standard tests, Cianferoni estimated that food allergy is common in 8% of young children and 4% of adults (2). Food al- lergy is used when a causal relationship occurs between a specific immunological mechanism and a specific food consumed, falling into three broad categories of immune reactions, including IgE-mediated, non-IgE-mediated and mixed. Other reactions without an immunologic basis are defined as food intolerances. IgE-mediated food al- lergies are usually rapid-onset in different organs, includ- ing skin (urticaria, angioedema, pruritus), gastrointesti- nal tract (nausea, abdominal cramp, vomiting, and diar- rhea), respiratory tract (rhinoconjunctivitis, asthma), and oral allergy syndrome, and anaphylaxis. As a result, IgE- mediated food allergies can sometimes result in death. A pathophysiological mechanism explains the whole pro- cess of the disease in IgE-mediated food allergies (3). In con- trast, non-IgE-mediated and mixed types of food allergies are linked to manifestations of delayed hypersensitivity re- actions, including gastrointestinal (eosinophilic esophagi- tis, eosinophilic gastroenteritis, food protein-induced en- teropathy, and food protein-induced allergic proctocoli- tis), pulmonary (asthma, Heiner’s syndrome), and cuta- Copyright © 2022, Journal of Kermanshah University of Medical Sciences. This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly cited.