Prevalence and clinical features of adverse food reactions in Portuguese adults

Abstract

BackgroundOnly one previous study, via telephone call, on the prevalence of self-reported food allergies has been performed in Portugal, in a small sample of adults. The objective of this study was to determine the prevalence of self-reported and probable food allergy, analyze the clinical features and involved foods in Portuguese adults.MethodsPopulation-based, cross-sectional study performed in various healthcare centres from central Portugal. All 1436 randomly selected individuals (median age: 45 years, 50.6 % female) replied to a validated food allergy questionnaire by phone. Those who reported an adverse food reaction were invited to come to the hospital, where clinical history was taken, skin prick (SPT) and prick-prick skin (SPPT) tests were performed and food allergen-specific IgE levels (sIgE) were determined. An open oral challenge was performed in selected cases. Cases of positive clinical history of immediate (up to 2 h after ingestion) reaction in association with positive food sIgE levels and/or skin prick tests were classified as IgE-associated probable food allergy. Cases of positive clinical history of delayed (more than 2 h after ingestion) and negative food sIgE levels independently of positive SPT or SPPT results were classified as non-IgE associated probable food allergy.ResultsThe prevalence of probable food allergy in our sample was 1 %, with shellfish and fish as the most frequently implicated foods. IgE-mediated probable food allergy occurred in 0.71 % of cases, with shellfish, peanut and nuts mainly involved. Cutaneous symptoms were most frequently reported. Prevalence values and food types were discrepant between self-reported and probable food allergies.ConclusionsThe prevalence of probable food allergies in Portuguese adults is low, is mostly related to shellfish, peanut and nuts and most frequently involves cutaneous symptoms.Electronic supplementary materialThe online version of this article (doi:10.1186/s13223-016-0139-8) contains supplementary material, which is available to authorized users.

Prevalence and clinical features of adverse food reactions in Portuguese children

“…Our results are different from those more frequently reported in children in other countries, in which the most prevalent foods have been cow’s milk, peanut, eggs, or wheat [ 18 , 24 , 28 ] although a German study in children and adolescents also found fruits as the most frequently reported and confirmed cause of food-induced symptoms [ 19 ]. Previous Portuguese reports also showed a high relevance of fresh fruits in AFR in adults [ 10 , 29 ] and in children with an age range similar to that in our study [ 11 ], and similar results were observed in Spanish children [ 30 ]. Since the diet followed by children in our study is similar to that in other regions of Portugal, the high prevalence of probable allergy to fresh fruits and fish may be due to the mediterranean type of diet of the population.…”

Anaphylaxis in a food allergy outpatient department: one-year review

“…As previously reported by studies of food allergy prevalence in European countries, in our patients the types of foods most frequently implicated are included in the so-called "big eight allergens": milk, egg, peanut, tree nuts, wheat, soy, fish and shellfish (4). However, and as Lozoya-Ibáñez et al reported in their work about self-reported food allergy, the individual prevalence of each food type is distinct, which may be due to cultural differences in food habits.…”

“…In the last decades, the prevalence of food allergies has increased in several regions throughout the world (3). Although food allergy is not as prevalent as other allergic diseases, its repercussions on dietary habits and social interaction is quite relevant (4). Allergic reactions to foods are the leading cause of anaphylaxis in patients of all ages outside the hospital setting (5); however, the precise risk of anaphylaxis is unknown (2).…”

Overcoming Shellfish Allergy: How Far Have We Come?

“…In Europe, a multi-center survey reported 4.8% of adults to have IgE sensitization to shrimp as compared to hazelnut (9.3%), peach (7.9%) and apple (6.5%) [15]. Shellfish was the leading food allergen in Portugal, affecting 34.6% of all food-allergic patients and 2.1% of the entire study population of 840 adults [16]. Most children from the Isle of Wight birth cohort reported shellfish allergy during adolescence, by which none of these subjects had IgE sensitization to shellfish at 1, 2, and 4 years while 0.2% of the subjects developed shellfish allergy at 10 and 18 years [17].…”