Lactase deficiency in patients with cow’s milk protein allergy – an individual approach to choosing infant formulas

The similarity of clinical symptoms of lactase deficiency and cow’s milk protein allergy (CMPA), as well as a frequent combination of these pathologies in the form of secondary hypolactasia against the background of CMPA often lead to under-diagnosis of CMPA and erroneous prescription of lactose-free and low-lactose formulas to children with food allergies. Children with the combination of CMPA and secondary lactase deficiency require complete elimination of milk protein from their diet and selection of extensively hydrolyzed or amino acid-based formulas in the absence or lack of breastfeeding. At the same time, exclusion of lactose from the child’s diet is not required in the absence of gastrointestinal manifestations of CMPA, and in the presence of secondary lactase deficiency against the background of CMPA, it is required only until gastrointestinal symptoms are relieved. Therefore, when remission of gastrointestinal manifestations of food allergies is achieved, it is recommended to transfer children to extensively hydrolyzed formulas containing lactose, since therapeutic formulas with lactose provide beneficial effects, including on the gut microbiota and fecal metabolome. This article presents a detailed analysis of literature and proposes an algorithm for individual selection of therapeutic formulas for children with CMPA, depending on clinical manifestations. Key words: cow’s milk protein allergy, amino acid-based formulas, extensively hydrolyzed formulas, children, lactase deficiency, infants, nutrition, food allergy