Clinical and pathogenetic features of allergic gastrointestinal diseases in children and modern approaches to nutritional support (literature review)

Allergic gastrointestinal diseases in children comprise a heterogeneous group of IgE-mediated, non-IgE-mediated and chronic immune-mediated conditions, including food protein-induced allergic proctocolitis (FPIAP), food protein-induced enterocolitis syndrome (FPIES), food protein-induced allergic enteropathy, and eosinophilic gastrointestinal diseases, including eosinophilic esophagitis. This review summarizes data on epidemiology, classification, pathogenesis, gut microbiome involvement, clinical phenotypes, diagnosis, nutritional support, prognosis and prevention. Particular attention is given to the differentiated use of extensively hydrolyzed and amino acid-based formulas and to prevention and correction of nutritional deficiencies associated with elimination diets. Unresolved issues include the lack of validated non-invasive diagnostic algorithms, limited domestic epidemiological data, and the need for further research on immune mechanisms and the role of the gut microbiota.