Milk Allergy: Causes, Symptoms, Diagnosis & Treatment
Most of us grew up hearing how good drinking milk is for the body. We heard how it would make us strong and healthy. But for some people, milk is a food allergen that can cause serious symptoms. In fact, it is one of the most common food allergies in children.
The good news is that 80 percent of children will outgrow their milk allergy by age 16, according to the American College of Allergy, Asthma & Immunology (ACAAI).
Many people think of milk allergy (sometimes referred to as “dairy allergy”) as a childhood problem. But adults can develop a sudden milk allergy as well.
What causes a milk allergy? Food allergy in general is caused by the immune system overreacting to a food allergen – in this case, milk. The immune system views cow’s milk – specifically the protein casein or whey – as a harmful invader. Once triggered, it sets off an immune response sparked by immunoglobulin E (IgE) allergy antibodies. This leads to allergy symptoms. This type of allergy is called an IgE-mediated food allergy.
What are milk allergy symptoms?
Symptoms may vary person to person. Some people may have a mild allergic reaction while others may be more serious. Symptoms typically occur within 30 minutes after consuming milk and may involve the skin, respiratory system, digestive system and/or the heart. Typical milk allergy symptoms in adults and children may include:
Itchy hives or skin rash
Nausea or vomiting
Coughing, wheezing or trouble breathing
Diarrhea (sometimes with blood, particularly in infants)
Abdominal pain or cramps
Tingling or itchy lips and mouth
In some cases a severe allergic reaction to milk called anaphylaxis can occur. Anaphylaxis is a severe reaction or life-threatening reaction. It consists of symptoms involving two or more body systems. In addition to the symptoms listed above, people experiencing anaphylaxis due to milk allergy may have symptoms such as:
tight or swollen mouth, lips or throat
drop in blood pressure
racing or faint pulse
dizziness or fainting
loss of consciousness
How is a milk allergy diagnosed?
First, keep a watch for allergy symptoms after you or your child consumes milk or milk products. Then, if symptoms occur, make an appointment with a board-certified allergist. An allergist is best equipped to perform milk allergy testing as part of a diagnosis.
The diagnosis process may include:
Health history and physical. The doctor will review your personal and family health history with allergy symptoms. They will also perform a a physical. This may involve examining the skin and listening to the lungs.
Skin prick test. In this test, the skin is pricked with a small amount of milk protein. After about 15 minutes, the skin is examined for signs of an allergic reaction to milk proteins. It’s usually a raised bump.
Blood tests. In this test, the doctor draws blood using a needle to test for elevated amounts of immunoglobulin E (IgE) antibodies. IgE antibodies develop as a result of an allergic reaction. A component blood test looks for allergy to the specific milk protein – casein or whey.
Oral food challenge. The doctor gives the patient a tiny amount of milk or milk protein. Then the doctor watches for signs and symptoms of an allergic reaction. It’s important that parents and patients not try this at home. It should only be done under the supervision of a doctor.
Using the test results, the allergist is able to determine if cow’s milk allergy is the cause of your symptoms.
What is the treatment for milk allergy?
Some people with milk allergies experience mild symptoms. For others, it can turn into a severe allergic reaction very question.
Mild symptoms may include just a few hives, a little swelling around the lips, and stomach discomfort. If mild symptom occur, call your doctor for recommendations on the best course of treatment. Mild allergy symptoms can turn into serious events – anaphylaxis, a severe allergic reaction – without warning. That’s why it’s important that anyone diagnosed with milk allergy be prepared for a severe reaction.
Severe milk allergy reactions can be life-threatening. It is critical to have immediate access to epinephrine, a dose of adrenaline that can treat medical emergencies. Epinephrine is the first line of treatment for anaphylaxis. It is the only medication that can reverse the life-threatening symptoms of anaphylaxis. Epinephrine should be administered as soon as symptoms arise. Severe allergic reactions can be fatal if left untreated. Since anaphylaxis is a medical emergency, call 9-1-1 for follow-up care.
Do not use an antihistamine such as Benadryl to treat anaphylaxis. Antihistamines only treat the skin rash or hives and stop the production of histamine. They do not treat other more severe symptoms of a severe allergic reaction.
For most people with milk allergy, the best treatment option is actually prevention. If you’re allergic to cow’s milk, do not consume milk or milk products, dairy products, or any other foods containing milk protein.
Is oral immunotherapy for milk allergy available?
Oral immunotherapy (OIT) for milk allergy is not approved by the U.S. Food and Drug Administration (FDA). However, allergists who specialize in milk allergy desensitization may offer it to certain patients.
Milk allergy OIT focuses on building tolerance to milk and milk protein. It aims to desensitize the body to the allergen. The treatment starts with a tiny amount of milk or milk protein, then gradually larger amounts, until a target dose is reached. Researchers have found that by building up allergen exposure slowly, it can desensitize the patient to higher doses. OIT should only be done in a doctor’s office or medical setting where treatment can be provided in case an allergic reaction. Do NOT attempt this on your own.
Milk allergy immunotherapy has been shown to be effective in several studies. One study found that 92.3% of participants were able to consume milk protein regularly after undergoing milk allergy OIT. However, there is a risk of adverse side effects during the treatment. (This is why OIT should only be done in a doctor’s office or medical facility.) And patients must consume milk daily even after OIT has ended. Stopping may reduce milk tolerance and increase the risk of a future allergic reaction.
It’s important to remember that oral immunotherapy is a treatment, not a cure. It is designed to reduce the frequency and severity of allergic reactions. Discuss the benefits and risks of milk allergy OIT with an allergist who specializes in the treatment.
What foods contain milk?
Milk is not just in a glass or a bowl of cereal. It is in many dishes and often “hidden” as butter, cream or cheese. It is one of the most difficult food allergens to avoid, says Stephanie Leonard, MD, a food allergy specialist at Rady Children’s Hospital-San Diego. “I think it’s harder to avoid than peanuts,” she says.
A host of food products in Western cuisine contain dairy – some obvious, others not so much.
Easily recognizable foods containing milk:
Foods that may contain milk:
White sauces (such as Alfredo)
Breads and biscuits
Cookies and cakes
Some chewing gum has lactose (milk sugar) sprayed on it. Some tortilla chips and microwave popcorn are coated in a dairy-based powder.
Interestingly, the baking process may denature milk protein. This means that the milk proteins change structure and may become less allergenic for some people with milk allergy. Studies have found that many children (about 75%) are able to tolerate milk products (such as baked goods) when the milk has been heated. Talk with your allergist about whether it is safe for you or your child to eat foods where the milk has been heated.
What should I look for on food labels to avoid milk products?
It’s important to read food labels for milk, milk products or dairy foods. As one of the nine most-common food allergens in the United States, cow’s milk is required to appear on food labels in the “contains” section.
The ingredients may also list milk proteins. The two main proteins in milk are casein (curds) and whey (watery part).
So if a product contains milk, it may be listed one of two ways:
within the ingredients in parentheses following the name of the allergen, such as “whey (milk)”;
in the “contains” section adjacent to the ingredients. Beware, however, the “contains” statement is not required for casein. A food can be promoted as “nondairy” on the front of the package even if it contains casein.
In addition to casein and whey, there are many other milk allergy terms. Some of these terms include:
Any protein or powdered milk (powder derived from milk)
Some foods may have traces of milk in them even if milk is not on the label. This can occur when the food, while being manufactured, prepared or served, comes in contact with something with milk in it. This is known as cross contact.
How to ensure healthy diet if you’re allergic to milk?
People who are allergic to milk – especially children – face challenges in getting essential nutrients in their overall diet. Cow’s milk is a natural source of 16 essential nutrients. An 8-ounce serving of nonfat milk provides about 30 percent of the recommended daily value (DV) of calcium, 8.25 grams of protein and is usually fortified with 45 percent of the recommended daily allowance (RDA) of vitamin D.
How to make sure these essential nutrients are part of your diet? The good news is grocery stores are increasingly stocked with milk alternatives. Soy, almond, rice, hemp and coconut milk can help supply nutrition in absence of milk. These milk alternatives vary in calories and other nutritional content. But most are enriched with comparable calcium and vitamin D levels.
Soy milk typically contains equal amounts of protein per serving as milk and 50 percent more calcium. It has fewer calories, no cholesterol and 30 percent of RDA of vitamin D. It’s also on par with cow’s milk in vitamins A and B12.
Unsweetened almond milk is a low-calorie option, containing 30 calories per cup. Rice and coconut milk are great sources of calcium. However, all three fall short in the protein department, coming in at just one gram per serving.
Hemp powder, which can be added to smoothies and other foods like muffins and oatmeal, has around 15 grams of protein per serving, depending on the brand. Other good sources of protein are tofu, legumes (peas, beans and peanuts are the most common), whole grains and eggs, which also contain vitamins D, A and B12.
A plant-based diet that includes leafy greens also serves as an excellent source for calcium and protein. Lentils and quinoa are great protein sources, with lentils coming in at a whopping 18 grams per 1 cup cooked. Keep in mind your body cannot absorb more than 30 grams of protein in one meal, so breaking it up between various sources throughout the day has its advantages.
Leafy greens are excellent sources of calcium. Tofu and white beans also fill the bill. Although packed with sugar, many juices are fortified with calcium as well. Salmon, tuna and sardines provide vitamin D. Liver and some fruits and vegetables have vitamin A, while meat, poultry and fish have B12.
Ask your doctor for a referral to a nutritionist who can help you or your child ensure a nutritionally balanced, milk-free diet.
Milk allergy in infants
Cow’s milk allergy is the most common food allergy in infants. Since babies are not able to communicate what they are feeling, it can be a challenge to identify milk allergy. Atopic dermatitis, or eczema, can be one of the first signs that a milk allergy is present. This is the start of the so-called allergic march.
When consuming milk, infants with a milk allergy may develop a skin rash, hives, and/or swelling around the mouth or face. They may have gastrointestinal symptoms. These may include nausea, vomiting, diarrhea, constipation or bloody stools. The symptoms may cause babies being unusually fussy or irritable.
Can milk allergy cause a diaper rash or newborn rash? The simple answer is no. A diaper rash is a type of irritant dermatitis. There is a similar condition called perianal dermatitis. This is a red rash around the genital area that is more moist and red than traditional diaper rash. A recent study found that cow’s milk allergy is a major contributor to recurrent perianal dermatitis.
What about milk allergy and breastfeeding? Breastfeeding has many known benefits to child development. But recent guidance from leading medical society says breastfeeding does not prevent food allergy. You may also wonder if a mom who consumes milk could potentially pass on a milk allergen to her baby through breast milk. A recent study indicates that, for 99% of babies with a milk allergy, breast milk does not contain enough of the allergen to cause an allergic reaction.
If you are concerned that your baby may have a milk allergy, talk with your child’s pediatrician or an allergist. If a milk allergy is confirmed, the doctor can help review what food products to avoid. For formula-fed infants, the doctor can also recommend alternate formula options.
Many children will outgrow their milk allergy, usually by their teenage years. It is important to work closely with a doctor or a nutritionist to make sure children with milk allergy don’t develop any nutritional deficiencies.
What is non-IgE-mediated milk allergy?
A non-IgE-mediated milk allergy is an immune system response that does not involve Immunoglobulin E (IgE) allergy antibodies. Why this happens is not fully understood. It could be the result of a developing digestive system in infants. Or it could be the result of a medical condition.
Non-IgE-mediated milk reactions can happen to anyone, but they are most common in infants and young children. Symptoms are usually delayed. They can appear two hours or even up to two days after consuming milk or milk products. Some people may experience common food allergy symptoms from a non-IgE-mediated reaction. Most others will experience different types of symptoms usually related to the digestive system. These include:
Skin symptoms, usually eczema
GERD, or reflux
Colic in infants
Unusual stools (diarrhea, blood in stools)
Poor weight gain in infants and young children
A non-IgE-mediated milk allergy very rarely leads to a life-threatening allergic response. It does not result in anaphylaxis.
There is no test to diagnose a non-IgE-mediated reaction. Doctors usually make the diagnosis based on the symptoms and food trial and error. This process can take a few weeks. It is possible for someone to have both an IgE-mediated allergy and non-IgE-mediated reaction.
Avoidance of milk and milk products is the best way to prevent a non-IgE-mediated milk reaction. You will need to work together with a doctor or nutritionist to develop a diet plan that is not only milk-free but also nutritionally balanced. Many children outgrow a non-IgE-mediated milk allergy. However, the condition could indicate the child may develop an IgE-mediated milk or food allergy later in life.
The most common non-IgE-mediated reaction to milk is lactose intolerance. This is a type of food intolerance. It can occur due to an enzyme deficiency or chemicals in the food. The meal is not “broken down” correctly in the body and causes stomach distress.
Food protein-induced enterocolitis syndrome (FPIES) is a rare but severe condition that is a non-IgE-mediated reaction. It primarily affects infants and young children. FPIES involves gastrointestinal distress to a food protein. Severe cases can lead to hospitalization. Any type of food can trigger FPIES, but the most common are cow’s milk, soy, rice and grains. FPIES requires different treatment plans.
Questions & Answers (Q&A) about Milk Allergies
Milk allergy can be scary when symptoms are severe. Managing it can be time-consuming since so many foods contain dairy products. Here are some frequently asked questions about milk allergies. If you would like to see another question answered, please email Gary Fitzgerald, Senior Editor
Is there a difference between milk allergy vs. lactose intolerance?
Yes, there is a difference between milk allergy and lactose intolerance. In milk allergy, milk or milk proteins trigger an immune response. Lactose intolerance does not involve the immune system.
Lactose is a sugar molecule found in milk. Lactase is an enzyme the body produces to help digest lactose. People who are lactose intolerant do not produce enough lactase. When they are unable to digest the lactose, it causes gastrointestinal symptoms.
Both milk allergy and lactose intolerance can cause gastrointestinal symptoms. But lactose intolerance is not as dangerous as milk allergy. It does not lead to a severe allergic reaction or anaphylaxis.
I'm allergic to milk. What can I eat?
If you or a loved one were recently diagnosed with a milk allergy, you may feel overwhelmed or anxious about what you can eat. Milk-free diets are increasingly common thanks to dairy alternatives: almond, soy, rice, coconut, hemp or oat milk.
It is important to read food labels carefully. Many foods contain milk or milk ingredients. They can be lurking in foods such as hot dogs, processed meats, egg substitutes, artificial butter flavor, or caramel candies. Also, just because something is labeled as “dairy free” or “nondairy” does not mean it is free of milk proteins.
Can you be allergic to milk but not cheese?
Most people with milk allergy will not be able to eat cheese made with cow’s milk or other milk from mammals (goat, sheep, etc.). However, they may be able to eat some non-dairy or vegan cheeses.
People who have a milk intolerance or are lactose intolerant may find they can eat cheese made with milk and not develop symptoms.
Is milk protein intolerance the same as a milk allergy?
A milk protein intolerance, unlike a milk allergy, does not involve the immune system. People with a milk protein intolerance usually experience stomach symptoms such as gas, cramps, bloating or diarrhea from consuming milk. They may be able to eat other dairy products without issue.
People with a milk allergy develop allergic symptoms after consuming milk or milk products. Symptoms may not only involve the stomach but also the skin, the respiratory system, and the heart.
Is there a specific type of hives or rash that develops as a result of milk allergy?
There is no way to tell from looking at hives or a rash if it is caused by a particular food or allergen. The best thing to do is get tested to find out for sure if your skin rash is caused by milk allergy.
Is goat's milk better than cow's milk for allergies?
If someone has a cow’s milk allergy, it is they will have an allergic reaction to goat’s milk or milk from other animals. Plant-based milks such as soy, almond, rice, coconut and oat are safer alternatives.
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Purvi Parikh, MD, FACAAI is an adult and pediatric allergist and immunologist at Allergy and Asthma Associates of Murray Hill in New York City. She is on faculty as Clinical Assistant Professor in both departments of Medicine and Pediatrics at New York University School of Medicine.
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