This article deals with lactose intolerance, which is defined as symptoms that occur upon exposure to lactose in individuals with lactose malabsorption.1 It is the result of an enzyme deficiency, rather than lactose allergy, which is an IgE-mediated reaction. For information about allergy, see the separate Food Allergy and Food Intolerance article.
This is a companion discussion topic for the original article at https://patient.info/doctor/lactose-intolerance-pro