Milk Allergy vs. Lactose Intolerance: What’s the Difference?

Over 160 foods can cause potentially serious issues in people who have food allergies, but the "Big-8" major food allergens account for 90 percent of all reactions. Of these major allergens, milk tops the list and eggs sit closely behind. Is this known as a dairy allergy? And does that mean that people who experience allergic reactions to milk are lactose intolerant?

Milk/Dairy Allergy

A milk allergy is caused when the body's immune system overreacts to the protein in the milk you consume. In extreme cases, an allergic reaction can occur by being near products that contain it. It's especially common in children, though they often outgrow the allergy. Symptoms of a milk allergy can include digestive issues like stomach cramps, nausea and diarrhea, or cause a skin rash, swelling of the mouth and breathing troubles after milk is ingested. Depending on the severity of the allergy, consuming milk could potentially be life-threatening. The FDA requires that all foods containing milk clearly list it on their nutritional labels, so reading them carefully is essential to staying healthy and safe.

One of the most difficult parts of dealing with a milk allergy — especially with your child's milk allergy — is explaining what that entails. The term "milk allergy" suggests that an allergic reaction will happen only when a person drinks cow's milk. But referring to the allergy as a "dairy allergy" may cause others to think that both milk and eggs should be avoided since eggs are often found in the dairy isle at the grocery, though this is a completely separate allergy. There is much debate on what to name it but, whatever you choose to call this allergy, it is important to explain that it is triggered by ingesting milk and foods that include it. If your child is allergic to milk, elaborate on what that means to the people who interact with him or her to be sure there are no issues.

Lactose Intolerance

The enzyme lactase normally breaks down the sugars found in milk and the products that contain milk. When the body doesn't have enough lactase, it is incapable of processing these sugars and causes digestive issues if milk is consumed. This issue is more common than having a milk allergy and can develop at any time over the course of life, though it is less serious than an allergy. Symptoms of lactose intolerance may include stomach cramps, nausea, gas or diarrhea if you eat or drink milk or dairy products. Your body may be able to handle small portions of low-lactose foods like cheese or yogurt, but beware of your body's limits.

If you think you may have developed an intolerance to lactose, visit your doctor. He or she may ask you to experiment with using dairy products and log your symptoms, but there are also a few tests that can confirm your suspicions. These can include a hydrogen breath test (since undigested lactose leaves high levels or hydrogen in your mouth), a stool acidity test or a food allergy test if a milk allergy is suspected.

>> Read more: Food Allergies and Intolerances Decoded

Maintaining a healthy, balanced diet without consuming milk products — whatever the reason may be — is essential to your wellbeing since milk is a vital source of calcium. Foods like broccoli and kale contain a high amount of calcium and there are many vegan diets to try, which contain no animal products by nature. If you've developed lactose intolerance later in life and miss having your morning glass of cold milk, try almond milk, a healthy lactose-free alternative. It is best to consult a doctor or nutritionist to develop a diet that incorporates the nutrients you need in a safe way.