Milk Allergy vs. Lactose Intolerance

Sep 10, 2018 | Allergies, Allergy Desensitization (Allergy shots), Food Allergies / Intolerance, News

Did You Know?

Dairy allergy can be confused with lactose intolerance because some of the symptoms of each are similar. However, what is actually happening on a biological level is quite different. Because food allergy can be life-threatening, it is important to distinguish between intolerance and allergy.


Lactose intolerance is the inability to digest a sugar called lactose found in dairy products. Normally, the small intestine produces an enzyme called lactase, which breaks down lactose, allowing it to be absorbed. When the small intestine does not make enough lactase enzyme, ingestion of lactose in dairy causes digestive symptoms such as gas, diarrhea, nausea, and abdominal pain.

Dairy allergy allergy occurs when the immune system overreacts to a milk protein by producing an antibody called immunoglobulin E, or IgE. This can be detected by skin testing and/or blood work performed by an allergist. When the IgE reacts with the milk protein, it triggers cells to release chemicals causing symptoms known as food allergy. In addition to digestive symptoms, allergy can cause skin, respiratory, or cardiac symptoms. Symptoms can range in severity from mild to life-threatening.

Lactose intolerance is treated by avoidance of lactose or by using supplementation of the missing lactase enzyme during meals. Products such as Lactaid have this enzyme added and may thus allow individuals with lactose intolerance to consume dairy without symptoms. Lactose intolerance is unlikely to resolve.

Dairy allergy, however, may be outgrown by young children. Over half of children with milk allergy will outgrow it by age 3-5. Testing by your allergist can determine when, and in what form, it is safe to introduce milk. Desensitization to dairy is also an option for some patients. There are multiple ways to achieve this, and your allergist can determine what your situation requires on an individualized basis.

Consult your doctor if you suspect you have either a lactose intolerance or a milk/dairy allergy, or call 309-452-0995 or 212-717-4404 to book an appointment with us today.