[The prevalence of food allergy to peanut and hazelnut in children in Tomsk Region].

Food allergy to peanuts and nuts is an actual problem of practical health care, associated with significant prevalence of this disease, severe clinical symptoms and difficulty of diet organization. Purpose of the study--to study the prevalence of food allergy to peanut and hazelnut in Russian children, the investigation of clinical characteristics of this disease, and the mechanisms of sensitization to allergen components. The cross-sectional study was performed in the framework of the EuroPrevall (No FP6-2006-TTC-TU-5 Proposal 045879). The first stage was performed in random samples of primary schoolchildren aged 7-10 years (n = 13 010) from the Tomsk Region, Russia using a standardized questionnaire. The case-control sample was recruited for the second stage (n = 1288). Thus who reported adverse reactions to food in the screening stage were considered as cases (n = 652), children without reported reactions were controls (n = 636). The case-control stage included the completion of a clinical questionnaire, skin-prick test (ALK-Abelly, Spain), serum specific IgE measurement and component-resolved diagnostic: IgE measurement of allergen components of peanut (Ara h1, Ara h26, Ara h34, Ara h8), hazelnut (Cor a1, Cor a8, Cor a11) and birch allergen Bet v1 (ImmunoCAP, Phadia, Sweden). The prevalence of food allergy to peanut and hazelnut in children aged 7-10 years in the Tomsk region is 0.08 and 0.09%, respectively. The manifestation of the food allergy to nuts occurs in the preschool years, main reactions associated with allergy to nuts were oral allergy syndrome (75-80%), gastrointestinal disorders (60-80%) and itching skin rash (20-50%). Sensitization to birch is significantly correlated with the level of specific IgE to hazelnut (r = 0.53, p < 0.05) and peanut (r = 0.56, p < 0.05). Sensitization to heat-labile proteins peanut Ara h8 (12.3%) and hazelnut Cor a1 (8.8%) (homologues of Bet v1) dominates in the sample of children with food sensitization, that determines the cross-reactivity mechanism in the formation of food sensitization in the studied sample. The prevalence of allergies to peanut and hazelnut in Russia is much lower than in Europe and North America. Sensitization to these foods develops by the mechanism of cross-reactivity with birch pollen allergen. This type of sensitization determines mild clinical symptoms of allergy to hazelnut and peanut.