Milk allergy

Milk allergy is an abnormal response by the body’s immune system to milk and products containing milk. Allergy to cow’s milk is the most common food allergy in infants and young children. Cow’s milk is the usual cause of milk allergy, but milk from sheep, goats, buffalo and other mammals also can cause a reaction. About 2.5 percent of children under three years old are allergic to milk. Nearly all infants who develop an allergy to milk do so in their first year of life.

Sensitivity to cow’s milk varies from person to person, and reactions can be unpredictable. An allergic reaction usually occurs soon after you or your child consumes milk. Signs and symptoms of milk allergy can range from mild to severe and can include wheezing, vomiting, hives and digestive problems. Milk allergy can also cause anaphylaxis — a severe, life-threatening reaction.

If your doctor suspects you might have a milk allergy, he or she will probably refer you to an allergist or allergy specialist for more testing. The allergy specialist will ask you questions — like how often you have the reaction, the time it takes between eating a particular food and the start of the symptoms, and whether any family members have allergies or conditions like eczema and asthma.

The allergy specialist may do a skin test on you. This involves placing liquid extracts of milk protein on your forearm or back, pricking the skin a tiny bit, and waiting to see if a reddish, raised spot forms, indicating an allergic reaction.

You may need to stop taking anti-allergy medications (such as over-the-counter antihistamines) or prescription medicine 5 to 7 days before the skin test because they can affect the results. Most cold medicines and some antidepressants also may affect skin testing. Check with the allergist’s office if you are unsure about what medications need to be stopped and for how long.

The doctor also might take a blood sample and send it to a lab, where it will be mixed with some of the suspected allergen and checked for immunoglobulin E (IgE) antibodies.

These types of tests are used for diagnosing what doctors call a fast-onset type of milk allergy. But for people whose allergic reactions to milk develop more slowly, skin and blood tests are not as helpful.

In these cases, doctors try to diagnose the person using a food challenge. The person is told not to eat or drink anything made with milk for a period of time — usually a few weeks. Then, during the challenge, the person eats foods containing milk under a doctor’s close supervision. If symptoms come back after eating milk products, it’s a pretty sure bet the person has a milk allergy.

To treat a milk allergy, the person who is allergic needs to completely avoid any foods that contain milk or milk products. Avoiding milk and milk products is the primary treatment for milk allergy.

Fortunately, most children outgrow milk allergy. Those who don’t outgrow it may need to continue to avoid milk products.

If you have a milk allergy, keep an epinephrine auto-injector (such as an EpiPen®, Auvi-Q™ or Adrenaclick®) with you at all times. Epinephrine is the first-line treatment for anaphylaxis. Keeping epinephrine with you at all times should be just part of your action plan for living with a milk allergy. It’s also a good idea to carry an over-the-counter antihistamine, which can help ease allergy symptoms in some people. But antihistamines should be used in addition to the epinephrine, not as a replacement for the shot.

If you accidentally eat something with milk in it and start having serious allergic symptoms — like swelling inside your mouth, chest pain, or difficulty breathing — give yourself the shot right away to counteract the reaction while you’re waiting for medical help. Always call for emergency help when using epinephrine. You should make sure your school and even good friends’ houses keep injectable epinephrine on hand, too.

If you’ve had to take an epinephrine shot because of an allergic reaction, go immediately to a medical facility or hospital emergency room so they can give you additional treatment if you need it. Sometimes, anaphylactic reactions are followed by a second wave of symptoms a few hours later. So you might need to be watched in a clinic or hospital for 4 to 8 hours following the reaction.

What is the difference between milk allergy and milk intolerance?

Milk allergy is often confused with lactose intolerance because people can have the same kinds of things happening to them (like stomach pains or bloating, for example) with both conditions. But they’re not related. A true milk allergy differs from milk protein intolerance and lactose intolerance. Milk allergy is a problem involving the immune system. Unlike milk allergy, milk intolerance doesn’t involve the immune system. Milk intolerance requires different treatment from true milk allergy.

Lactose intolerance involves the digestive system (which doesn’t produce enough of the enzyme needed to break down the sugar in milk).

Common signs and symptoms of milk protein intolerance or lactose intolerance include digestive problems, such as bloating, gas or diarrhea, after consuming milk or products containing milk.

What happens with a milk allergy?

Food allergies involve the body’s immune system, which normally fights infection. When someone is allergic to a particular food, the immune system overreacts to proteins in that food.

People who are allergic to cow’s milk react to one or more of the proteins in it. Curd, the substance that forms chunks in sour milk, contains 80% of milk’s proteins, including several called caseins. Whey, the watery part of milk, holds the other 20%. A person may be allergic to proteins in either or both parts of milk.

Every time the person eats these proteins, the body thinks they are harmful invaders. The immune system responds by kicking into high gear to fend off the “invader.” This causes an allergic reaction, in which chemicals like histamine are released in the body.

The release of these chemicals can cause someone to have the following problems:

• wheezing
• trouble breathing
• coughing
• hoarseness
• throat tightness
• stomachache
• vomiting
• diarrhea
• itchy, watery, or swollen eyes
• hives
• red spots
• swelling
• a drop in blood pressure

Milk allergy is like most food allergy reactions: It usually happens within minutes to hours after eating foods that contain milk proteins.

Although it’s not common, milk allergies can cause a severe reaction called anaphylaxis. Anaphylaxis may begin with some of the same symptoms as a less severe reaction, but then quickly worsen. A person might have trouble breathing, feel lightheaded, or pass out. If it’s not treated, anaphylaxis can be life-threatening.

Do these ingredients contain milk?

People allergic to milk often have questions about the following ingredients. These ingredients do NOT contain milk protein and are safe to eat.

• Calcium lactate
• Calcium stearoyl lactylate
• Cocoa butter
• Cream of tartar
• Lactic acid (however, lactic acid starter culture may contain milk)
• Oleoresin
• Sodium lactate
• Sodium stearoyl lactylate

Milk allergy causes

All true food allergies are caused by an immune system malfunction. If you have milk allergy, your immune system identifies certain milk proteins as harmful, triggering the production of immunoglobulin E (IgE) antibodies to neutralize the protein (allergen). The next time you come in contact with these proteins, IgE antibodies recognize them and signal your immune system to release histamine and other chemicals, causing a range of allergic signs and symptoms.

There are two main proteins in cow’s milk that can cause an allergic reaction:

• Casein, found in the solid part (curd) of milk that curdles
• Whey, found in the liquid part of milk that remains after milk curdles

You or your child may be allergic to only one milk protein or to both. These proteins may be hard to avoid because they’re also in some processed foods. And most people who react to cow’s milk will react to sheep’s, goat’s and buffalo’s milk. Less commonly, people allergic to cow’s milk are also allergic to soy milk.

Food protein-induced enterocolitis syndrome (FPIES)

A food allergen can also cause what’s sometimes called a delayed food allergy. Although any food can be a trigger, milk is one of the most common. The reaction, commonly vomiting and diarrhea, usually occurs within hours after eating the trigger rather than within minutes.

Unlike some food allergies, food protein-induced enterocolitis syndrome usually resolves over time. As with milk allergy, preventing an food protein-induced enterocolitis syndrome reaction involves avoiding milk and milk products.

Risk factors for developing milk allergy

Certain factors may increase the risk of developing milk allergy:

• Other allergies. Many children allergic to milk also have other allergies. Milk allergy may develop before other allergies.
• Atopic dermatitis. Children who have atopic dermatitis — a common, chronic inflammation of the skin — are much more likely to develop a food allergy.
• Family history. A person’s risk of a food allergy increases if one or both parents have a food allergy or another type of allergy or allergic disease — such as hay fever, asthma, hives or eczema.
• Age. Milk allergy is more common in children. As they age, their digestive systems mature, and their bodies are less likely to react to milk.

Milk allergy prevention

There’s no sure way to prevent a food allergy, but you can prevent reactions by avoiding the food that causes them. If you know you or your child is allergic to milk, avoid milk and milk products.

Read food labels carefully. Look for casein, a milk derivative, which can be found in some unexpected places, such as in some canned tuna, sausage or nondairy products. Question ingredients when ordering in restaurants.

Sources of milk

Obvious sources of allergy-causing milk proteins are found in dairy products, including:

• Whole milk, low-fat milk, skim milk, buttermilk
• Butter
• Yogurt
• Ice cream, gelato
• Cheese and anything that contains cheese
• Half-and-half

Milk can be harder to identify when it’s used as an ingredient in processed foods, including baked goods and processed meats. Hidden sources of milk include:

• Whey
• Casein
• Ingredients spelled with the prefix “lact” — such as lactose and lactate
• Candies, such as chocolate, nougat and caramel
• Protein powders
• Artificial butter flavor
• Artificial cheese flavor
• Hydrolysates

Even if a food is labeled “milk-free” or “nondairy,” it may contain allergy-causing milk proteins — so you have to read the label carefully. When in doubt, contact the manufacturer to be sure a product doesn’t contain milk ingredients.

When eating out, ask how foods have been prepared. Does your steak have melted butter on it? Was your seafood dipped in milk before cooking?

If you’re at risk of a serious allergic reaction, talk with your doctor about carrying and using emergency epinephrine (adrenaline). If you have already had a severe reaction, wear a medical alert bracelet or necklace that lets others know you have a food allergy.

Milk alternatives for infants

In children who are allergic to milk, breast-feeding and the use of hypoallergenic formula can prevent allergic reactions.

• Breast-feeding is the best source of nutrition for your infant. Breast-feeding for as long as possible is recommended, especially if your infant is at high risk of developing milk allergy.
• Hypoallergenic formulas are produced by using enzymes to break down (hydrolyze) milk proteins, such as casein or whey. Further processing can include heat and filtering. Depending on their level of processing, products are classified as either partially or extensively hydrolyzed. Or they may also be called elemental formulas. Some hypoallergenic formulas aren’t milk based, but instead contain amino acids. Besides extensively hydrolyzed products, amino-acid-based formulas are the least likely to cause an allergic reaction.
• Soy-based formulas are based on soy protein instead of milk. Soy formulas are fortified to be nutritionally complete — but, unfortunately, some children with a milk allergy also develop an allergy to soy.

If you’re breast-feeding and your child is allergic to milk, cow’s milk proteins passed through your breast milk may cause an allergic reaction. You may need to exclude from your diet all products that contain milk. Talk to your doctor if you know — or suspect — that your child has milk allergy and develops allergy signs and symptoms after breast-feeding.

If you or your child is on a milk-free diet, your doctor or dietitian can help you plan nutritionally balanced meals. You or your child may need to take supplements to replace calcium and nutrients found in milk, such as vitamin D and riboflavin.

Milk allergy symptoms

Milk allergy symptoms, which differ from person to person, occur a few minutes to a few hours after you or your child drinks milk or eats milk products.

Immediate signs and symptoms of milk allergy might include:

• Hives
• Wheezing
• Itching or tingling feeling around the lips or mouth
• Swelling of the lips, tongue or throat
• Coughing or shortness of breath
• Vomiting

Signs and symptoms that may take more time to develop include:

• Loose stools or diarrhea, which may contain blood
• Abdominal cramps
• Runny nose
• Watery eyes
• Colic, in babies

Anaphylaxis

Milk allergy can cause anaphylaxis, a life-threatening reaction that narrows the airways and can block breathing. Milk is the third most common food — after peanuts and tree nuts — to cause anaphylaxis.

If you or your child has a reaction to milk, tell your doctor, no matter how mild the reaction. Tests can help confirm milk allergy, so you can avoid future and potentially worse reactions.

Anaphylaxis is a medical emergency and requires treatment with an epinephrine (adrenaline) shot (EpiPen, Adrenaclick, others) and a trip to the emergency room. Signs and symptoms start soon after milk consumption and can include:

• Constriction of airways, including a swollen throat that makes it difficult to breathe
• Facial flushing
• Itching
• Shock, with a marked drop in blood pressure.

Milk allergy complications

Children who are allergic to milk are more likely to develop certain other health problems, including:

• Allergies to other foods — such as eggs, soy, peanuts or even beef
• Hay fever — a common reaction to pet dander, dust mites, grass pollen and other substances

Milk allergy diagnosis

When food causes an allergic reaction, it isn’t always easy to pinpoint what food is to blame. To evaluate whether you or your child has milk allergy, your doctor may:

• Ask detailed questions about signs and symptoms
• Perform a physical exam
• Have you keep a detailed diary of the foods you or your child eats
• Have you eliminate milk from your diet or your child’s diet (elimination diet) — and then have you add back the food to see if it causes a reaction

Your doctor may also recommend one or both of the following tests:

• Skin test. In this test, your skin is pricked and exposed to small amounts of the proteins found in milk. If you’re allergic, you’ll likely develop a raised bump (hive) at the test location on your skin. Allergy specialists usually are best equipped to perform and interpret allergy skin tests. Keep in mind that this type of test isn’t completely accurate for detecting milk allergy.
• Blood test. A blood test can measure your immune system’s response to milk by measuring the amount of immunoglobulin E (IgE) antibodies in your blood. But this test isn’t completely accurate in identifying a milk allergy.

If your examination and test results can’t confirm milk allergy, your doctor might administer an oral challenge, in which you are fed different foods that may or may not contain milk in increasing amounts to see if you react to the ones that contain milk. It’s a good idea to have allergy tests administered by an allergist who’s been trained to manage serious reactions.

If your doctor suspects that your symptoms are caused by something other than a food allergy, you may need other tests to identify — or rule out — other medical problems.

Milk allergy treatment

The only way to prevent an allergic reaction is to avoid milk and milk proteins. This can be difficult because milk is a common ingredient in many foods. Also, some people with milk allergy can tolerate milk in some forms, such as milk that’s heated in baked goods, or in some processed foods, such as yogurt. Talk to your doctor about what to avoid.

Despite your best efforts, if you or your child accidentally consumes milk, medications such as antihistamines may reduce a mild allergic reaction.

If you or your child has a serious allergic reaction (anaphylaxis), you may need an emergency injection of epinephrine (adrenaline) and a trip to the emergency room. If you’re at risk of having a severe reaction, you or your child may need to carry injectable epinephrine (EpiPen, Adrenaclick, others) at all times. Have your doctor or pharmacist demonstrate how to use this device so that you’re prepared for an emergency.

Avoiding milk

To prevent a reaction, it is very important that you avoid cow’s milk and cow’s milk products. Always read food labels and ask questions about ingredients before eating a food that you have not prepared yourself.

If you are allergic to cow’s milk, your doctor may recommend you also avoid milk from other domestic animals. For example, goat’s milk protein is similar to cow’s milk protein and may cause a reaction in people who have a milk allergy.

Milk is one of the eight major allergens that must be listed on packaged foods sold in the U.S., as required by federal law.

Avoid foods that contain milk or any of these ingredients:

• Butter, butter fat, butter oil, butter acid, butter ester(s)
• Buttermilk
• Casein
• Casein hydrolysate
• Caseinates (in all forms)
• Cheese
• Cottage cheese
• Cream
• Curds
• Custard
• Diacetyl
• Ghee
• Half-and-half
• Lactalbumin, lactalbumin phosphate
• Lactoferrin
• Lactose
• Lactulose
• Milk (in all forms including condensed, derivative, dry, evaporated, goat’s milk and milk from other animals, low-fat, malted, milkfat, non-fat, powder, protein, skimmed, solids, whole)
• Milk protein hydrolysate
• Pudding
• Recaldent(R)
• Rennet casein
• Sour cream, sour cream solids
• Sour milk solids
• Tagatose
• Whey (in all forms)
• Whey protein hydrolysate
• Yogurt

Other possible sources of milk:

• Artificial butter flavor
• Baked goods
• Caramel candies
• Chocolate
• Lactic acid starter culture and other bacterial cultures
• Luncheon meat, hot dogs and sausages, which may use the milk protein casein as a binder. Also, deli meat slicers are often used for both meat and cheese products, leading to cross-contact.
• Margarine
• Nisin
• Non-dairy products, as many contain casein
• Nougat
• Shellfish is sometimes dipped in milk to reduce the fishy odor. Ask questions when buying shellfish.
• Tuna fish, as some brands contain casein
• Some specialty products made with milk substitutes (i.e., soy-, nut- or rice-based dairy products) are manufactured on equipment shared with milk.
• Many restaurants put butter on grilled steaks to add extra flavor. You can’t see the butter after it melts.
• Some medications contain milk protein.

Allergens are not always present in these food and products, but milk protein can appear in surprising places. Again, read food labels and ask questions if you’re ever unsure about an item’s ingredients.

Milk in Kosher Foods

• Kosher Dairy: A “D” or the word “dairy” following the circled K or U on a product label means the product contains or is contaminated with milk protein. Avoid these products if you have a milk allergy.
• Kosher Pareve: A food product labeled “pareve” is considered milk-free under kosher dietary law. However, a product may be considered pareve even if it contains a very small amount of milk protein—possibly enough to cause an allergic reaction in certain people. Do not assume that these products will always be safe.

Milk allergy prognosis

Most children eventually outgrow a milk allergy. The allergy is most likely to continue in children who have high levels of cow’s milk antibodies in their blood.

Blood tests that measure these antibodies can help your allergist determine whether or not a child is likely to outgrow a milk allergy.