The results of the evaluation of the frequency and risk factors of developing food allergies, particularly its etiological structure and immunological characteristics in children of HELL, which has several pharmacologically stable chronic diseases are presented in the article. Food allergy was detected in 65% of children. Etiological structure of food sensitiveness has its own characteristics in accordance with the nosology of the disease. Children with atypical signs of disease show a combination of pathogenic mechanisms of development of food allergy.