The aim of our work was to study the structure and prevalence of the infectious syndrome in children from Kaliningrad Region with moderate-to-severe allergic pathology, with a complex manifestations of allergic reactions, both on skin and on the mucous membranes of the digestive and respiratory tract.
 Ninety children from 0 to 18 years old with various symptoms of allergic pathology were examined and included in the study group using standard clinical, objective and laboratory criteria. The severity of clinical course was associated with the severe and long-lasting symptoms, as well as with frequent bacterial and bacterial-fungal complications, with impaired quality of life and night sleep. The children were consulted by the specialists in otorhinolaryngology, hematology, pulmonology, surgery, ophthalmology, infectology, endocrinology, cardiology. Diagnoses according to nosological forms were made in accordance with the current clinical recommendations of Russian Ministry of Health. Our article presents data on concomitant infectious diseases and their impact on general condition and severity of hypersensitive responses. The average age of allergic manifestations in the group of children was 3.12±2.72 years. The average duration of the disease in the observed group was 7.5±0.88 years. The number of boys in our group prevailed (n = 56) by 1.6 times. Complicated heredity factors were reported by 15% of the patients’ parents. However, with careful collection of medical history taking, upon dynamic observation, the aggravated heredity on the mother’s side was detected in 45.56% (n = 41), and on the father’s side, in 31.1% of cases (n = 28). In eight families, both parents suffered from allergic pathology, in siblings, 21.1% (n = 19) of the examined children had allergies. In the families, including grandparents, allergic pathology was reported in 56 cases (62.2%).
 Almost all patients had problems with nasal breathing, 77 (85.6%) children with adenoid hypertrophy had a habit of breathing through the mouth. Postnasal drip syndrome was found in 78 cases. Allergic rhinitis with adenoid hypertrophy is, generally, accompanied by postnasal leakage, which can provoke aspiration bronchitis and pneumonia, especially if pathogenic or opportunistic flora is transferred to the nasal cavity and/or to the pharynx.
 Conclusions: 1. Identification and rehabilitation of chronic foci of infection, bacterial, fungal, should be a necessary component of the personalized therapy of allergic pathology in children. 2. In cases of recurrent sowing or finding of pathogenic flora (iodophilic flora, fungi, coccal flora) in the coprogram, one should exclude not only transient lactase deficiency, but also congenital lactase deficiency, thus preventing development of enterocolitis in the future like as worsening of skin status and respiratory manifestations. 3. In case of severe respiratory viral infections in children during the period of adaptation for pre-school institutions, one should exclude sensitization to allergens of house dust mites and epidermal allergens of domestic animals. 4. A comprehensive and personalized approach to the diagnosis of allergic disorders and comorbid conditions enables us to create conditions for stable remission, making it possible to conduct allergen-specific immunotherapy, which may provide a disease-modifying effect upon the hyperreactive states in our patients.