Milk Allergy: Symptoms, Testing, and Treatment

A milk allergy describes an abnormal immune system response that is triggered by cow’s milk consumption. Milk allergy is incredibly common, particularly among children — though many carry milk allergy into adulthood.

Statistically, this is the single most common allergy in infants and young children. Recent studies estimate that as many as 3% of babies are allergic to cow’s milk at one year old. As many as 2 in every 100 children under the age of four are allergic to dairy. 

While many people can naturally outgrow a milk allergy, this is not always the case. Properly treating a milk allergy — and understanding how to avoid its many different forms — is crucial to avoid serious allergic and even life-threatening episodes. 

This leaves parents and adults with many questions. What’s the difference between milk allergy and lactose intolerance? What about dairy allergies? Or casein or whey allergies? What are the symptoms and causes of milk allergy? What kinds of foods should you avoid? How is milk allergy diagnosed — and more importantly, how can it be treated? In the sections below, we’ll explore each of these questions, providing a comprehensive overview of everything you need to know about milk allergy diagnosis and treatment.

What is a Milk Allergy?

A milk allergy occurs when your body tries to fight specific milk proteins it perceives as threats. Your immune system then creates an antibody called Immunoglobulin E (IgE) that sets off an immune response that can result in a number of different types of symptoms. Some reactions may seem small – itching, swelling, etc – but when multiple symptoms occur that impact at least two bodily systems, a milk allergy can lead to anaphylaxis and be life-threatening.

How is Milk Allergy Different from Lactose Intolerance?

Lactose intolerance is characterized as a food intolerance, meaning it does not trigger an autoimmune response. Instead, lactose intolerance causes a gastrointestinal response, interfering with normal digestion when milk and dairy products are consumed. 

Those who are lactose intolerant are unable to produce the enzyme lactase, which breaks down lactose (a sugar present in milk and diary). This results in symptoms such as nausea, cramps, bloating, diarrhea, and gas. While certainly uncomfortable, and can impact quality of life, lactose intolerance is not life-threatening.  

Milk allergy may sound the same as lactose intolerance — but there are key differences between a milk allergy and an intolerance or sensitivity to milk. Milk allergy, like all food allergies, is an immune-mediated response. If you have a milk allergy, your body will automatically respond to milk proteins as though they are harmful, dangerous compounds. As milk proteins bind to IgE (immunoglobulin E) antibodies created by the immune system, this triggers a chain of allergic reactions that can range from mild to severe.

In some cases, allergic reactions can even be life-threatening. This is why it is so important to properly diagnose whether someone suffers from a true milk allergy or an intolerance.

What is the Difference Between Milk and Dairy?

The terms milk and dairy are frequently used interchangeably, although dairy is a much broader category of foods. Dairy products are foods that are produced from milk and include items such as cheese, yogurt, and butter. Milk (and the raw milk that is used to produce dairy products) is often cow’s milk, although other mammals like goats and sheep can produce milk that is used as well. 

If you are allergic to cow’s milk, there is a high likelihood that you will also be allergic to other animal milk products.

What are the Symptoms of a Milk Allergy Reaction?

Symptoms can range from mild to severe. As with any significant food allergy, some reactions can even be life-threatening. Some of the most common symptoms of milk allergy reaction include: 

    • Wheezing
    • Hives
    • Shortness of breath
    • Coughing
    • Swelling in the lips, tongue, or throat
    • Itching or tingling sensations in the mouth
    • Vomiting
    • Abdominal cramps
    • Watery eyes
    • Runny nose

Severe reactions can induce anaphylaxis, which can be life-threatening. Anaphylaxis occurs when the immune system sends a rush of chemicals to fight off invading proteins, causing the body to go into shock. Signs of anaphylaxis can include:

    • Pale or bluish tint on the skin 
    • Throat constriction
    • Shortness of breath (and/or wheezing)
    • Difficulty breathing
    • Confusion and/or dizziness
    • Weak, rapid pulse

Those with a diagnosed dairy allergy are advised to carry two epinephrine auto-injectors (such as an EpiPen®) at all times. 

Milk Allergy Testing and Diagnosis

There are four ways to determine whether someone has a milk allergy. These include: 

Skin Prick Test

A skin prick test is a safe and low-risk way for a clinician to evaluate food allergies.  First, a clinician will lightly prick the skin with a diluted allergen, ensuring that any skin reactions are closely observed and monitored. Bumps, hives, and mild itchiness are the most common reactions. A skin prick test is most accurate when the patient has not taken an antihistamine and has not used a topical steroid cream on their skin for a minimum of 5 days. 

Blood Test

A blood test will measure the amounts of IgE antibodies that the immune system has deployed as a response to milk proteins. Once drawn, the blood is sent to a lab to be evaluated, with results available within a few days. Infants and children can both safely undergo blood testing for dairy allergy.

Component Test

A component test is a  secondary type of blood test that determines whether a patient can tolerate certain components of milk protein. These tests can guide a clinician toward specific protein fragments that can be safely consumed without adverse reaction.  For example, a component test may help determine that you are unable to consume uncooked milk, but can safely tolerate baked milk.

Oral Food Challenge

An oral food challenge is often used as the final step in determining whether a food allergy has been outgrown, or when skin and blood tests are inconclusive. As the gold standard of allergy testing, an oral food challenge can determine, with certainty, whether milk products may safely be consumed. The clinician must complete a full patient history review, as an oral food challenge is only performed when a patient is clinically determined as likely to pass. Under close supervision and observation, the patient will consume small amounts of milk in increasing portions over three to four hours.  

Foods & Ingredients to Avoid with a Milk Allergy

There are two primary proteins that can cause an allergic reaction: casein and whey. Casein is found in the solid part of milk that curdles, while whey is found in the liquid. Those who suffer from a dairy allergy may either have a casein allergy, a whey allergy, or both. 

Not surprisingly, both casein and whey are found in a vast variety of dairy products. And while milk allergy is typically linked to cow’s milk, adverse reactions can also stem from goat, buffalo, or sheep’s milk. Examples of common foods to avoid include: 

    • Cheese
    • Cottage cheese
    • Custard
    • Cream
    • Buttermilk
    • Pudding
    • Sour cream
    • Yogurt
    • Milk in all forms (including powdered milk and evaporated milk)

Products that contain milk ingredients and protein can also trigger an allergic reaction, such as foods that are made with dairy, whey, lactose, and casein. Those with a dairy allergy should stay away from these allergy-triggering ingredients

    • Butter, butter fat, butter oil, butter acid, butter ester(s)
    • Diacetyl (often found in butter flavoring)
    • Rennet casein (milk protein often used in processed cheese or deli meats)
    • Tagatose (often used as an artificial sweetener)
    • All forms of whey (concentrate, isolate, and hydrolysate)
    • Any artificial butter or cheese flavoring

Milk proteins and by-products are present in far more than dairy products, which can make it challenging to avoid allergic triggers. Check the label on salad dressings, baked goods, cereals, donuts, cake mixes, and any canned or processed meats to ensure there are no harmful ingredients.

How is Milk Allergy Treated at Latitude Food Allergy Care?

Milk Allergy Treatment with Oral Immunotherapy

Persistent milk allergy can be treated with oral immunotherapy (OIT) in patients of all ages. Historically patients with milk allergies have been guided to avoid all dairy products. Unfortunately, avoidance is not easy nor is it foolproof. Luckily, avoidance is no longer the only answer. 

Latitude’s evidence-based program is built on clinical studies and protocols from leading research institutions, including Stanford, Duke, and Baylor. Our clinical partnerships with UCSF and Weill-Cornell ensure that we continue to provide the highest level of specialized food allergy care. In fact, 92% of Latitude OIT patients successfully reach maintenance and are desensitized to their allergens.

Effectiveness of Oral Immunotherapy in Milk Allergy Treatment

Research has demonstrated that OIT is safe and effective in minimizing reactions to unsuspected contact with food allergens. A 2016 study, one of many to arrive at the same conclusion, showed that adverse reactions were markedly reduced in patients who underwent OIT to cow’s milk, significantly improving their safety and quality of life. 

Oral immunotherapy gradually exposes the patient to small doses of an allergen over time. This desensitizes the body and helps to retrain the immune system, decreasing adverse allergic reactions. At Latitude Food Allergy Care, oral immunotherapy is offered for multiple allergens with or without Xolair: an anti-IgE monoclonal antibody that helps suppress allergic reactions.

Oral immunotherapy can be an effective milk allergy treatment, whether the patient has a casein allergy, whey allergy, or both.

For many, oral immunotherapy also creates dramatic improvements in overall quality of life, providing a safeguard against reactions to accidental exposures and empowering them with greater dietary flexibility. At Latitude, 92% of OIT patients are successfully desensitized to their allergens.

Is OIT Safe for Treating Milk Allergies?

Yes. OIT may sound scary, particularly for patients who have experienced severe allergic reactions. However, when conducted under the guidance of a trained clinician, OIT is safe and effective in treating food allergies

Can a Milk Allergy Be Cured?

There is no guaranteed cure for milk allergies, but there are methods you can follow to provide safety and treatments that can reduce your risk. First, be aware of the ingredients that could trigger a milk allergy reaction. Milk allergy testing including oral food challenges can provide clarity on your specific triggers.

Avoidance isn’t the only answer, though. Oral immunotherapy is an effective treatment for milk allergies, and can provide protection against accidental exposures. Talk with your doctor to understand what options are available to help you live more freely.

Are you or someone you love impacted by a milk allergy? Improve your quality of life and unlock a better future with Latitude Food Allergy Care. Latitude offers comprehensive food allergy care including diagnosis, treatment, and prevention for babies, children, and adults. Contact us today to schedule a no-obligation conversation with one of our Patient Care Coordinators.

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