A milk allergy can be life-threatening, while lactose intolerance is not.

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Key Differences

There is an overlap in symptoms between amilk allergyandlactose intolerance.

But that’s where their similarities end.

A person pouring milk into a glass at home

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They are vastly different conditions.

Milk (Dairy) Allergy

Food allergiesare not uncommon.

Allergy to dairy, or cow’s milk, is one of the most prevalent food allergies.

Jurairat J. Molina, MD

In contrast, a cow’s milk allergy can causeanaphylaxis.

Anaphylaxis is a sudden, serious, and life-threatening allergic reaction.

It can cause trouble breathing and other symptoms.

The treatment isepinephrine, which is given through an injection (an EpiPen).

People who have food allergies may be advised to carry an epinephrine injector with them at all times.

It is brought on by the body’s inability to produce an enzyme called lactase.

Lactase is needed to break down and digest lactose.

Lactose intolerance can affect anyone but usually starts after infancy.

Most babies can digest milk.

After infancy, the production of lactase may decrease, causing a reduced ability to digest lactose.

It’s thought that close to 70% of people are lactose intolerant.

As undigested lactose passes through thedigestive systemand into the colon, it may cause symptoms.

The bacteria in the colon break down lactose, which leads to by-products of fluid and gas.

Lactose intolerance can cause severe symptoms in some people.

However, it is not considered a serious illness for which people may need medical attention.

It’s possible to “outgrow” a milk allergy.

To manage a milk allergy and avoid symptoms, it’s important to remove milk from the diet.

This may include milk from animals other than cows, such as goat’s milk.

Potential symptoms of a cow’s milk allergy are numerous.

Why Am I Suddenly Allergic to Milk?

Adults can develop new food allergies.

It is likely to be a complex combination of several factors at once.

It’s not possible to know if someone will develop an allergy as they get older.

Signs of Lactose Intolerance

The symptoms of lactose intolerance range from mild to severe.

If the symptoms start in infancy, they may be more likely to be an allergy.

Testing is available to help confirm or rule out a milk allergy.

Also, there’s more to managing an allergy than simply avoiding the food, especially for children.

To diagnose food allergies, a healthcare provider will :

Possible tests include:

These tests are not foolproof.

Ways to Manage Symptoms

For a milk allergy, management includes avoiding milk products.

This can be challenging since it’s not always easy to identify milk protein.

If you experience an allergic reaction, it is important to treat it right away.

One treatment is to use over-the-counter or prescription antihistamines.

These medications may help reduce the allergic response.

A healthcare provider can create a specific plan regarding medications to use and when.

Instructions are based on the severity of the symptoms.

This can include:

Summary

A milk allergy is different from lactose intolerance.

The two conditions are not related, and an allergy is more serious than an intolerance.

A milk allergy should be diagnosed and managed with the help of a healthcare provider.

2018;11:111-120. doi:10.2147/JAA.S162456.

National Institute of Diabetes and Digestive and Kidney Diseases.Lactose intolerance.

2010;3(4):57161. doi:10.1097/WOX.0b013e3181defeb9

Food Allergy Research & Education (FARE).Milk allergy.

2019;2(1):e185630.

doi:10.1001/jamanetworkopen.2018.5630

Food Allergy Research & Education (FARE).Food allergy diagnosis and testing.

Food Allergy Research & Education (FARE).Food allergy action plan center.