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WGO Handbook on Diet and the Gut_2016_Final

World Digestive Health Day WDHD – May 29, 2016 FOOD ALLERGY AND THE DIGESTIVE TRACT, continued food allergic reactions in North America: milk, eggs, peanuts, tree nuts, soy, wheat, fish, and shellfish.9 The most common food allergens affecting adults are shellfish, fish, peanuts, and tree nuts.2 By the time a child reaches school age—in approximately 80% of cases—allergies to milk, eggs, soy, and wheat have usually abated.9 A recent systematic review provides a relatively recent estimate of the prevalence of food allergy in Europe.10 Studies published in Europe from January 1, 2000 to September 30, 2012 were identified from searches of four electronic databases. Two independent reviewers appraised the studies and extracted the estimates of interest. Data were pooled using random-effects meta-analyses. Fifty studies were included in a narrative synthesis and 42 studies in the meta-analyses. Although there were significant heterogeneity between the studies, the overall pooled estimates for all age groups of self-reported lifetime prevalence of allergy to cow’s milk, egg, wheat, soy, peanut, tree nuts, fish, and shellfish were 6.0, 2.5, 3.6, 0.4, 1.3, 2.2, and 1.3, respectively. The prevalence of food-challenge-defined allergy to these same foods were on average 10-fold less compared to the self-reported food reactions. Allergy to cow’s milk and egg was more common among younger children, while allergy to peanut, tree nuts, fish, and shellfish was more common among the older ones. Allergy to most foods, except soy and peanut, appeared to be more common in Northern Europe. The heterogeneity between studies was high and participation rates varied across studies, reaching as low as <20% in some studies. Asia is a populous and diverse region and a recent review aimed to summarize the current literature on food allergy from this region, comparing it with western populations. A PubMed search using strategies “Food allergy AND Asia”, “Food anaphylaxis AND Asia”, and “Food allergy AND each Asian country” was conducted.11 Fifty-three articles, published between 2005 and 2012, were reviewed. The overall prevalence of food allergy in Asia was comparable to the West, but the types of food allergy differed in order of relevance. Shellfish was the most common food allergen in Asia, likely reflecting the abundance of seafood consumption in this region. Symptoms varied widely, from oral symptoms to anaphylaxis, within given individuals. In contrast, peanut prevalence in Asia was extremely low compared to the West for unclear reasons. Egg and cow’s milk allergy were the two most common food allergies in young children and infants, with prevalence data comparable to western populations. Differences within Asia were also noted. Though uncommon in most Asian countries, wheat allergy is the most common cause of anaphylaxis in Japan and Korea, and is increasing in Thailand. This study highlights important differences between East and West, and within the Asian region. Eosinophilic esophagitis (EoE) occurs in children and adults with a strong male preponderance. There has been a marked increase in EoE in North America, Europe, and Australia. The reasons for this increase remain unclear, but are likely to be influenced by genetic and environmental factors, as well as early-life exposures. Based on recent population-based data, the estimated EoE prevalence in the USA is 56.7 per 100,000 persons.12 The peak prevalence was observed in patients between 35 and 39 years of age. Prevalence figures in Asia and the Middle East generally appear to be lower than in Western countries, but population-based studies are not available. Although celiac disease and EoE can occur in given individuals, typically males, a causal association between celiac disease and EoE appears unlikely. Additional population-based studies are needed to define the epidemiology of EoE. In summary, food allergy occurs worldwide with varying prevalence according to specific food consumption and geographic regions. Food allergies, including EoE and celiac disease, are increasing in prevalence over time and are more frequent in western countries. However, data for all countries and regions of the world is incomplete. REFERENCES 1. NIAID Expert Panel; Boyce JA, Asa’ad AA, et al. Guidelines for the diagnosis and management of food allergy in the United States: report of the NIAID-sponsored expert panel. J Allergy Clin Immunol. 2010;26(6 Suppl):S1-S58. 2. Leung, J., Crowe, S.E., Food allergy and food sensitivity. In: Nutritional Care of the Patient with Gastrointestinal Disease. Buchman, A. ed, Boca Raton, FL: CRC Press, Taylor & Francis Group, 63-87, 2015. 3. Chafen JJS, Newberry SJ, Riedl MA, et al. Diagnosing and managing common food allergies: a systematic review. JAMA. 2010;303(18):1848-1856. 4. Bischoff S, Crowe SE. Gastrointestinal food allergy: new insights into pathophysiology and clinical perspectives. Gastroenterology. 2005;128(4):1089-1113. World Digestive Health Day WDHD May 29, 2016 WGO Handbook on DIET AND THE GUT 27


WGO Handbook on Diet and the Gut_2016_Final
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