Characteristics of beef allergy in schoolchildren in Turkey

Background: The prevalence of immunoglobulin E (IgE) mediated beef allergy in childhood is unknown. We investigated the prevalence and characteristics of IgE-mediated beef allergy in urban schoolchildren. Methods: This cross-sectional study recruited 6000 randomly selected urban schoolchildren ages 6-17 years from the city center of Giresun in the eastern Black Sea region of Turkey during 2013. Children with suspected IgE-mediated beef allergy, determined by a self-administered questionnaire, after providing written consent, were skin-prick tested with commercial beef and cow's milk solutions and prick-prick tested with raw, boiled, and fried beef. Levels of serum-specific IgE to beef specific IgE and serum-specific IgE to cow's milk were determined by using fluorescent enzyme immunoassay. All children with suspected beef allergy were invited for a double-blind, placebo controlled food challenge (DBPCFC) to determine the prevalence of IgE-mediated beef allergy. Results: The response rate to the questionnaire was 82.2%. The estimated prevalence of parental-reported IgE-mediated beef allergy was 2.6%. The prevalence of IgE-mediated beef allergy confirmed by DBPCFC was 0.30% (95% confidence interval, 0.18-0.5%). Positive challenge responses were observed in 70.6% (p = 0.027), 76.9% (p = 0.027), and 73.3% (p = 0.028) of the children with a positive family history of beef allergy, positive skin test results, and positive beef specific IgE values, respectively. A beef specific IgE value of > 5 kUA/L alone or a combination of a positive family history of beef allergy, positive skin test results, and beef specific IgE values of > 3 kUA/L yielded a positive response to DBPCFC. Conclusion: The presence of a family history of beef allergy, beef specific IgE value, and skin test result positivity are independently associated with positive DBPCFC results, and combined evaluation of these three parameters increased the positive predictive power of the tests.