Dairy Allergy: What It Is And How To Know If You Have It

Dairy Allergy
Dairy Allergy

Although milk is widely considered an excellent source of dietary calcium and protein, it is also one of the most common allergens in the world, particularly among children. According to the American College of Allergy, Asthma, and Immunology, about 2.5% of children aged three or younger are allergic to dairy products. The good news is about 80% of children will likely outgrow their dairy allergy by the age of 16.1

Understanding Your Allergy

Dairy Allergy Versus Milk Allergy

Dairy allergy is the blanket term used for an allergy to milk and all milk-based products. Specifically, a dairy allergy is an allergy to the milk proteins casein (comprising about 80% of the protein in milk ) and whey (about 20%).2 Having an actual allergy to milk usually means having to avoid all dairy products including butter, cheese, yogurt, ice cream, sour cream, ghee, whey, milk chocolate, cream cheese and so on.3


Dairy Allergy Versus Lactose Intolerance

Many people think that dairy allergy is the same as lactose intolerance. But contrary to popular belief, the two are completely unrelated!4 Individuals who have a dairy allergy experience allergic symptoms to milk because their immune system recognizes casein and/or whey as harmful substances. In turn, this causes the immune system to overreact and triggers hives, vomiting, itching, and even anaphylactic shock in extreme cases, which can be life-threatening. Yeah, it’s not fun.

In comparison, people who are lactose intolerant are unable to digest the sugar component in milk – lactose – due to low levels of an enzyme called lactase. Consuming milk or derivative products when you’re lactose intolerant can lead to symptoms such as diarrhea, gas, or abdominal cramps, but this condition is not life-threatening. Sure, you’ll be uncomfortable, but you’ll live!


People with a dairy allergy will be intolerant and/or allergic to milk and all milk-based products. However, those who are lactose intolerant can be sensitive to some milk products but not others, depending on how the milk fat is processed in specific derivative products.5 For example, someone who is lactose intolerant may be able to digest yogurt easily but could experience discomfort with cheese or butter. The specific reaction depends on how the casein and whey in each product were broken down and processed during production.

What’s Causing Your Dairy Allergy?

Like all other food allergies, an allergy to milk and dairy products is caused by a malfunction in the good old immune system. When a person allergic to dairy consumes milk or milk products, their immune system recognizes casein and/or whey as dangerous intruders and produces antibodies called immunoglobulin E (IgE). The next time the person consumes milk or other dairy products, the IgE rushes to neutralize the threat (milk proteins) by triggering the immune system to release chemicals called histamines which can cause a variety of allergic reactions.6


Does Heredity Play A Role?

Yes, you can blame mom and dad for this one! Studies have also shown that having a parent or sibling who is allergic to milk significantly raises your likelihood of also being allergic to milk. In case of hereditary allergies, a dairy allergy is usually not something you outgrow and physicians recommend dairy alternatives to make sure you’re getting vital nutrients in your diet.7

Dairy Allergy: Symptoms And Reactions

As per Food Allergy Research & Education (FARE), sensitivity or intolerance for milk and related products differs from person to person. Immediate symptoms may include hives, rashes, itching, vomiting, swelling of the throat/lips/tongue, nausea, shortness of breath and wheezing. Symptoms that may take longer to manifest can include abdominal cramps, diarrhea (sometimes bloody), runny nose, and in babies, colic. Sometimes, people who are severely allergic to milk can go into anaphylactic shock after consuming milk and milk products. This is a life-threatening condition where the airways become constricted, making it difficult to breathe.8


Detecting A Dairy Allergy

Like all food allergies, a milk allergy can often be difficult to identify. Initially, a physician may ask you to keep a detailed food log. They may also recommend that you eliminate milk and milk-based products from your diet for a period of time and then reintroduce them to see if they trigger a reaction. Your physician may also recommend skin and blood tests to confirm a suspected dairy allergy.9

  • Skin test: In a skin-prick test, an allergist will prick the skin on your back or forearm with a small probe, expose it to a fluid containing milk proteins, and allow it to seep into your skin. If reddish, elevated welts start to develop on your skin in about 15–20 minutes, it can indicate a dairy allergy. This is a crucial step in confirming your allergy.
  • Blood test: A blood test can be simpler, quicker, and less painful. Your blood sample will be tested to see if it contains high levels of specific IgE antibodies.

Managing Your Dairy Allergy

Your allergist may recommend a number of options for managing your dairy allergy depending on the severity of your intolerance. Options may include:

  • Avoiding milk and milk-based products completely. This can be tricky because milk is a fairly common ingredient in many products. Read nutrition labels on product packaging carefully. Since milk is one of the most common allergens, manufacturers of milk-based products in the US are legally required to clearly state milk as an ingredient in their products.
  • You may be able to tolerate milk in products that have been cooked at very high temperatures, such as baked goods. Consult with your allergist about what milk products may be safe to consume for you. Hey, any excuse to consume baked goodies, right?
  • If you accidentally consume milk or a milk-based product, over-the-counter antihistamines may help relieve mild allergic reactions.
  • If you have a severe milk allergy and end up consuming a milk-based product, you may need a trip to the ER where you may be given an epinephrine injection. Some people choose to carry EpiPens with them so they’re prepared for an emergency.

Dairy Alternatives

We get it, a dairy allergy can be an inconvenient condition preventing you from having many things that you find irresistible. The good news, however, is that it is a very manageable condition.

For infants allergic to milk, breastfeeding is the best option. In fact, studies have shown that breastfeeding infants instead of feeding them milk formula can even prevent milk allergy.10 Human breast milk also contains casein, but unlike dairy milk, about 60–80% of human breast milk is whey. This makes it easier to digest for little humans and they tend to tolerate it better.11 Infants can also be given hypoallergenic and soy-based formulas after consulting with your pediatrician.12


It’s possible to meet your nutritional needs without consuming milk and milk-based products. For children and adults, soy milk, almond milk, hazelnut milk, rice milk, hemp milk, and quinoa milk can be excellent substitutes for dairy milk with comparable nutritional benefits.13 Whip up a batch of almond milk by blending soaked almonds with water until creamy and smooth. Strain and add a touch of salt, vanilla, or cinnamon – you sure won’t miss milk after this!

In addition to consuming dairy milk alternatives, make sure to eat plenty of vegetables that are high in calcium. Most leafy greens such as kale, broccoli, collard greens, spinach, and bok choy are loaded with calcium. Bonus: they also give you great skin! If you’re not too crazy about leafy greens (we won’t judge), try salmon, scallops, hummus, oranges, figs, and tofu. These are calcium-rich foods as well and will help you maintain optimal bone and teeth health.