Lactose intolerance in infants is caused by lactase deficiency, most of which can be self-resolving, while a small percentage cannot be self-resolving.
Lactase deficiency can be categorized into congenital lactase deficiency, primary lactase deficiency, and secondary lactase deficiency. Congenital lactase deficiency and primary lactase deficiency are autosomal disorders that cannot be completely cured. Lactose intolerance is self-limiting and most of them can be cured on their own, while a small proportion of the more severe congenital lactase deficiency cannot be cured on their own.
Secondary lactase deficiency is secondary to other diseases, such as intestinal infections, and is not genetically related. Whether or not it resolves depends on the primary disease. Lactose intolerance can also resolve spontaneously if the infection is mild and resolves.
When lactose intolerance occurs in infants, it is recommended to seek medical attention to identify the cause and standardize the treatment.