Gastrointestinal disorders in secondary lactase deficiency: diagnostic features, methods of correction

A modern problem of practical pediatrics is secondary lactase deficiency - intolerance to dairy products containing lactose, which develops in response to a decrease in lactase activity due to enterocyte damage in an infectious, allergic, or other inflammatory process in the intestine, atrophic changes in the intestinal mucosa, and antibacterial drugs. Secondary lactase deficiency leads to flatulence, abdominal pain, and diarrhea - clinical manifestations that impair the quality of life and slow down the recovery process. An important aspect is the differential diagnosis of secondary lactase deficiency and organic and functional diseases of the gastrointestinal tract. The aim of the study is to summarize the literature data on the features of the clinical picture, diagnosis, and methods of correction of secondary lactase deficiency in children. According to the literature review, it is known that lactase deficiency can be primary or secondary and manifest clinically in both children and adults. There are various etiologic factors for the development of secondary lactase deficiency, which defines it as an urgent problem in pediatrics and a common cause of dyspeptic and abdominal syndrome in children. The clinical manifestations of secondary lactase deficiency are nonspecific and similar to the signs of organic and functional gastrointestinal diseases. The severity of the manifestations depends on the amount of lactose consumed and the level of lactase activity. Diagnostics of secondary lactase deficiency involves the use of invasive and non-invasive research methods, among which the leading role belongs to the hydrogen breathing test with a load of food lactose. Modern methods of treating secondary lactase deficiency include the administration of enzyme replacement therapy - lactase, the use of which will allow preserved breastfeeding for young children and rational nutrition for older children. The authors declare no conflict of interest.