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 dairy 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 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.

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). Without lactase, the digestive system is unable to break down lactose, causing 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 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.

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.  

Key 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 be triggered by only one protein or by 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?

Persistent milk allergy can be treated with oral immunotherapy (OIT) in patients of all ages. Research has consistently 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.

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. OIT is approximately 85 percent effective when overseen by a skilled clinician who specializes in food allergen treatment.

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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