Prevalence and clinical features of adverse food reactions in Portuguese adults

• Published in: Allergy, asthma, and clinical immunology asthma, and clinical immunology, 2016-08, Vol.12 (1), p.36-36, Article 36
• Main Authors: Lozoya-Ibáñez, Carlos, Morgado-Nunes, Sara, Rodrigues, Alexandra, Lobo, Cláudia, Taborda-Barata, Luis
• Format: Article
• Language: English
• Subjects: Allergens; Diagnosis; Food allergy; Health aspects; Prevalence studies (Epidemiology)
• ISSN: 1710-1484; 1710-1492; 1710-1492
• DOI: 10.1186/s13223-016-0139-8

Only 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. Population-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. The 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. The prevalence of probable food allergies in Portuguese adults is low, is mostly related to shellfish, peanut and nuts and most frequently involves cutaneous symptoms.