Atopic dermatitis in preschool children: prevalence, clinical and allergic characteristics and risk factors

Background. Information on atopic dermatitis (AD) epidemiology in preschool children is scarce. Objectives. To estimate the prevalence, clinical, allergological characteristics and risk factors of AD in preschool children. Materials and methods. 5156 children aged 3-6 years old living in the Altai Territory participated in the study. The study included a screening and clinical phases. At the screening stage of the study the prevalence of AD was evaluated using the Russian version of the ISAAC questionnaire, risk factors were evaluated using the additional questionnaire. At the clinical stage diagnosis of AD was verified by allergists. Results. The prevalence of atopic dermatitis was 9,9%. 73,8% of children had mild AD; 58,5% of children were sensitized: 25 (15,6%) to food allergens - 12 (7,2%) to egg, 12 (7,2%) to cow’s milk, 6 (3,6%) to wheat flour and 8 (4,9%) to fish. The most important inhaled allergens were house dust mites, the sensitivity to them was diagnosed in 44 (26,8%) children. The family anamnesis of allergic diseases increases risk of development of AD by 5 times (OR=5,7; 95% CI=4,1-7,9; p<0,01), smoking of parents - by 1,7 times (OR=1,7; 95% CI=1,1 to 2,6; p<0,05); impropriate intake of vitamin D3 in the first year of life increases risk of development of AD by 2,8 times (OR=2,8; 95% CI=2-3,9; p<0,01). Conclusion. The prevalence of AD among children aged 3-6 years old is 9,9%, the majority of children have mild disease, and 57,3% of the children sensitized to one or more allergens. Risk factors of AD in preschool age are allergic family history, passive smoking and impropriate intake of vitamin D3 in the first year of life.