What is the difference between cow's milk allergy and lactose intolerance?

Cow's milk allergy and lactose intolerance are two different conditions that are both related to milk consumption, but they have different causes, symptoms, and treatment methods.

Cow’s milk allergy is an immune reaction to the proteins in cow’s milk, such as casein and whey proteins. The immune system recognizes these proteins as harmful invaders and responds by producing antibodies. Common symptoms include rash, hives, itching, swelling (usually of the face, lips, or throat), difficulty breathing, wheezing, coughing, vomiting, diarrhea, and abdominal pain.

Lactose intolerance is caused by a deficiency of lactase, the enzyme that breaks down lactose (the sugar in milk) in the small intestine. When lactose is not properly digested, it attracts water in the intestines and is fermented by bacteria in the large intestine, leading to symptoms. Common symptoms include bloating, abdominal pain, flatulence, diarrhea, and sometimes nausea.

Source: https://www.mayoclinic.org/diseases-conditions/milk-allergy/symptoms-causes/syc-20375101

Source: https://www.niddk.nih.gov/health-information/digestive-diseases/lactose-intolerance

Author: Prof. Dr. Dirk Devroey - Latest update: 2024-08-07 - Copyright: Clinifacts 2024