Author(s): Ranc F, Grandmottet X, Grandjean H
BACKGROUND: A cross-sectional, descriptive, questionnaire-based survey was conducted in Toulouse schools to determine the prevalence of food allergies among schoolchildren. OBJECTIVES: The first goal of the survey was to estimate the prevalence of food allergies. The second goal was to determine the main characteristics of the allergies.
METHODS: The questionnaires (3500) were distributed in 150 classes in eight schools. The return rate was 77.6% (2716).
RESULTS: Of the 192 (7.0%) questionnaires with a 'Yes' response (report of a food allergy), 182 were retained as reporting true food allergies (6.7%). The cumulative and point prevalences were 6.7% [95% confidence interval (CI) 5.8-7.6] and 4.7% [95% CI 3.9-5.5], respectively. The point prevalences were 4.0% for the children aged 2-5 years, 6.8% for the children aged 6-10 years, and 3.4% for the children aged 11-14 years. The main foods reported as causing adverse reactions were cow milk (n = 29, 11.9%), eggs (n = 23, 9.4%), kiwis (n = 22, 9.0%), peanuts (n = 20, 8.2%), fish (n = 19, 7.8%), tree nuts (n = 19, 7.8%), and shrimp (n = 13, 5.3%). The average age at which the allergies were detected was 3.4+/-2.8 years (with a range of 0.1-12 years). The clinical signs of the food allergies were cutaneous (n=153, 62.7%), digestive (n = 74, 30.3%), respiratory (n = 17, 6.9%), and anaphylactic shock (n = 12, 4.9%).
CONCLUSION: While well aware of the biases inherent in this type of study, we estimated the cumulative and point prevalences of food allergies in a population of school-age children in Toulouse at 6.7% and 4.7%, respectively. Cow milk, eggs, and peanuts were the main foods reported as causing allergies. Exotic fruits, shellfish, and tree nuts appeared to be relatively new allergens.Journal of Allergy & Therapy