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.
Common Symptoms of Milk Allergy
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:
- Shortness of breath
- Swelling in the lips, tongue, or throat
- Itching or tingling sensations in the mouth
- 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 include: reactions in two systems of the body (ie, the skin and the lungs, the lungs and the stomach, etc…) a weak and rapid pulse, dizziness or fainting, low blood pressure, and constricted airways. Those with a diagnosed dairy allergy are advised to carry an epinephrine auto-injector (such as an EpiPen®) at all times.
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:
- Cottage cheese
- Sour cream
- 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 Diagnosed?
There are four ways to determine whether someone has a milk allergy. These include: