Milk Allergy – Causes, Treatment options

Milk Allergy


A milk allergy is a potentially deadly allergic reaction to one or more of the proteins found in cow’s milk or dairy products. It differs from milk intolerance, which is a sensitivity to the sugar found in milk products and does not involve the immune system. Symptoms of a milk allergy often include itchiness, rash, hives (smooth, raised pink or white bumps that appear on or beneath the skin), stomach cramps, nausea and difficulty breathing.

Symptoms can range from mild anaphylaxis (generalized reaction involving two or more body systems) to potentially life-threatening anaphylactic shock, which involves breathing problems and lowered blood pressure. It is impossible to know whether a person with a milk allergy is likely to have mild or severe symptoms after ingesting the proteins. Therefore people with milk allergies need to avoid all foods containing milk proteins and need to seek immediate medical attention in the case of accidental exposure.

The only effective treatment for milk allergies is to completely remove milk and dairy products from the diet. By practicing diligent avoidance, an individual can successfully remove the threat of a milk allergy reaction.

While milk allergies are common in young children, 70 to 80 percent of infants with a milk allergy outgrow it by the age of 4, according to the American Academy of Pediatrics. However, some individuals do not outgrow their milk allergies and must permanently remove milk from their diets. Once a person has had an allergic reaction to milk, they should never attempt to reintroduce milk to the diet without the supervision of a physician.

Milk proteins are found in a variety of substances, particularly dairy products such as butters and cheeses. Some manufactured items (e.g., latex gloves) also contain milk proteins and must be avoided by anyone with a milk allergy. Because of the large number of products that contain milk proteins, individuals with this condition must pay very close attention to what they eat and come into contact with.

Removing milk completely from the diet can cause certain dietary concerns. Milk is a good source of several vitamins and minerals – particularly calcium. Individuals who remove milk from their diets should consult their physicians to learn how to properly supplement their diets with additional foods or vitamins.

About milk allergy

A milk allergy is a potentially deadly allergic reaction to one or more dairy proteins. It is one of the eight food allergies that make up 90 percent of all known food allergies, according to the Food Allergy and Anaphylaxis Network (FAAN ). The only way to successfully treat a milk allergy is to completely remove milk and dairy products from the diet.

It is important to note that a milk allergy is not the same as a milk intolerance, a sensitivity to the sugar found in milk products which does not involve the immune system and is usually less severe.

Milk allergies are most common in young children, who usually develop the condition within the first six months of life. According to the Asthma and Allergy Foundation of America, studies have shown that 2 to 5 percent of children develop a milk allergy in the first year of life. Parents usually discover that an infant has a milk allergy when the child has a reaction to baby formula.

According to the American Academy of Pediatrics, 70 to 80 percent of infants with milk allergies outgrow the condition by the age of 4. However, some milk allergy conditions persist throughout adulthood. It is rare for an adult to develop a milk allergy.

An allergic reaction to milk occurs when one of the milk proteins makes its way into the body of an allergic individual. This usually occurs when the protein is consumed, though it can also occur when an individual absorbs milk protein through the skin (some latex gloves contain milk protein). Once the protein is inside the person’s body, an allergic cascade is triggered as the immune system misinterprets the protein as a dangerous substance.

The immune system produces specific milk IgE antibodies that appear in the bloodstream. These antibodies bind to body cells (mast cells and basophils). The next time IgE antibodies come in contact with the offending milk protein, histamines and other chemicals are released into the blood, which stimulates allergy symptoms.   

Symptoms may range from mild anaphylaxis (generalized reaction involving two or more body systems) to life-threatening anaphylactic shock, which involves breathing problems and lowered blood pressure.

The symptoms of a milk allergy usually occur in one of two different ways. These include:

  • Rapid onset. This type of reaction usually occurs suddenly, often only a few minutes after consuming a milk protein. Anaphylaxis symptoms can occur swiftly and severely with this type of reaction, and it can be fatal if not properly treated.

  • Slower onset. This is the most common type of reaction to a milk protein. This reaction often occurs several hours after ingesting milk. Symptoms usually involve the gastrointestinal system.

There are some alternatives to milk and dairy products. Soybeans, tofu, rice milk and soy milk can often be used in the place of milk or dairy products, and can also be good sources of calcium. About 10 percent of individuals with a milk allergy can tolerate milk from sheep or goats. However, because goat’s milk and sheep’s milk share common allergens or cross re-act with cow’s milk, individuals should initially try these alternatives only under a physician’s supervision.

Milk allergies are often passed on genetically, meaning a child that comes from a family with a history of allergies – particularly a food allergy – is more likely to have a milk allergy. Families that have a history of allergic rhinitis (hay fever), eczema (inflammatory skin disease with lesions that usually appear very dry, thickened or scaly) and other allergies all have an increased risk of producing children with allergies.

A recent study also suggests that method of birth may play a role in a child’s reaction to milk. Children delivered by Cesarean section (a procedure in which a baby is delivered through an incision in the mother’s abdomen) appear to be twice as likely to develop a milk allergy or milk intolerance.

The signs and symptoms of milk allergies are the same as other food allergies. The most common symptoms include:

  • Wheezing (a whistling or high-pitched sound that results when breathing tubes are narrowed or obstructed)

  • Hives (smooth, raised pink or white bumps that appear on or beneath the skin)

  • Skin rash

  • Eczema

  • Nausea

  • Vomiting

  • Diarrhea

  • Swelling (around them mouth and lips)

  • Abdominal cramps

  • Bloated sensation

  • Asthma (a chronic inflammation of the bronchial [airway] tissues that produces shortness of breath, chest tightness, coughing and wheezing)

Potential causes of milk allergy

There are several types of proteins in cow’s milk responsible for triggering milk allergies. Casein is the main protein, and is responsible for 80 percent of the protein in milk. Casein is found in the solid curd that forms when milk is allowed to separate and sour. Most of the other proteins are found in the whey, which is the watery remaining part. An individual can be allergic to proteins from either part, or to both.

Dairy proteins are found in many types of foods, making it important for people with a milk allergy to carefully check the ingredients of food products before they are consumed. All of these common ingredients may contain milk proteins (Note: This is not a complete list):

  • Milk, including condensed milk, dry milk, evaporated milk, malted milk, milkfat, powdered milk and mild solids
  • Butter, artificial butter, butter solids, butter fat, butter oil and buttermilk
  • Brown sugar flavoring
  • Calcium
  • Caramel color or flavoring
  • Casein, caseinate and rennet casein
  • Cheese
  • Cottage cheese
  • Cream
  • Curds
  • Custard
  • Ghee
  • Half & half
  • High protein flour
  • Ice cream
  • Lactalbumin, lactalbumin phosphate, lactoglobulin, lactulose
  • Lactose
  • Nougat
  • Pudding
  • Sour cream, sour cream solids, sour milk solids
  • Whey
  • Yogurt

Milk proteins can also be found in a number of unexpected places. People with a milk allergy should be careful when consuming the following:

  • Chocolate
  • Margarine
  • Processed meats (e.g., bologna, pepperoni, salami, hot dogs, sausage)
  • Bread and breaded foods (often fried)
  • Soy cheeses
  • Canned tuna fish
  • Chicken broth
  • Hydrolyzed vegetable protein
  • Chewing gum

In addition, kosher foods (foods that are in accordance with Jewish dietary laws) that are labeled with the symbols “D” or “DE” should be avoided. The presence of a “D” on a food product’s package indicates that the product contains milk protein. The presence of the symbol “DE” indicates that the product was produced on equipment that is shared with dairy products. Kosher foods labeled “pareve”, “parev” or “parve” are considered milk-free in accordance with Jewish law. However, these markings do not guarantee that the product is safe to consume. Pareve foods can be up to 1.5 percent milk protein.

Some medicines use lactose as a filler. This does not necessarily mean these medicines are off–limits to a person with a milk allergy, since lactose is a sugar and not a protein. Still, there is some evidence that small amounts of some milk proteins can be found in lactose and may affect highly sensitive individuals with milk allergies.

The milk protein casein is used in some types of manufacturing and can be found in several kinds of latex glove. Skin contact with this latex is enough to trigger an allergic skin reaction in many individuals with a milk allergy.

Related allergies and conditions

Because both are triggered by milk, a milk allergy is often confused with milk intolerance (or lactose intolerance), which is not an allergy. An allergy always involves an exaggerated response by the immune system to a substance that, in most people, does not cause a reaction.

Milk intolerance is a sensitivity to the sugar found in milk products (lactose). In people with this condition, the small intestine is unable to produce enough of a specific enzyme (lactase) to break lactose down for easy digestion. The result of the undigested lactose is symptoms of diarrhea, gas and abdominal cramps. Symptoms of milk intolerance generally involve discomfort, but pose little risk. Milk allergy reactions, however, are potentially life-threatening. Some individuals with milk intolerance can tolerate some forms of dairy, whereas people with a milk allergy must avoid dairy completely.

Food poisoning can also be mistaken for a milk allergy because it can produce the same symptoms. Food poisoning occurs when an individual consumes food that is contaminated with microorganisms such as bacteria. Consuming contaminated milk can cause gastrointestinal symptoms such as nausea, vomiting, abdominal cramps and diarrhea.

Because individuals with a milk allergy must completely remove milk and dairy products from their diets, a calcium deficiency can result. This condition causes bone weakening and skeletal abnormalities. Fortunately, regular supplements or dietary additions can replace the missing calcium. Foods such as fish and vegetables can also help replace calcium. A physician can help evaluate a milk allergic individual’s diet and suggest an appropriate kind of calcium supplement.

A latex allergy can share the symptoms of a milk allergy, occasionally complicating a milk allergy diagnosis. While both are true allergies that involve an immune system reaction, latex allergies are typically triggered by external contact with latex, which is the flexible, elastic material used in many rubber products. Latex allergies can also be triggered by inhaling latex particles that have become airborne.

Diagnosing milk allergy

The methods used to diagnose milk allergies are very similar to those used in other food allergies. It can be relatively simple to diagnose a milk allergy when milk is already a suspected allergen trigger. 

The first step a physician is likely to take in the diagnosis of a milk allergy is to create a detailed medical history and dietary history of the patient. The most basic question a physician will ask is whether an individual has a consistent reaction each time milk and milk products are consumed. Other questions may focus on the frequency of reaction, timing of symptoms after eating a particular food and family history of allergies and other conditions (e.g., asthma, eczema).

The physician will also perform a physical examination to help identify or exclude medical problems that may be causing the patient’s symptoms. To be sure that milk is the culprit, a physician will often administer one or more of the following tests:

  • Skin test. This test involves scratching, pricking or injecting an individual’s skin with milk protein. In some cases, a patch soaked in milk protein is taped onto the patient’s skin instead. The tested area will react with redness or swelling to indicate an allergic response.   

  • RAST (radioallergosorbent test). This type of blood test allows a laboratory to directly test a blood sample from an individual in an attempt to detect antibodies that correspond to a milk allergy.  

  • Elimination diet. This test involves removing milk from an individual’s diet for several weeks to see if allergic reactions persist. If the reactions do indeed stop, it can be presumed that milk was the culprit.

  • Oral food challenge. Different foods are placed within capsules to hide their identity. The patient consumes the capsules without knowing which capsule contains the suspected allergen and the physician looks for signs of an allergic reaction.

Treatment options

The only form of treatment for milk allergy is the complete removal of milk from the diet. Food allergies can be deadly if avoidance is not practiced diligently.

By checking ingredient lists for milk and milk products, people can limit their exposure to milk proteins. New legislation may make it easier for people to determine if a food item contains a potential milk allergen (a substance the body perceives as a threat, triggering an allergic reaction). As of January 2006, food manufacturers are required by the U.S. Food & Drug Administration (FDA) to clearly list food allergens on their product labels.

Individuals with milk allergies should also be particularly vigilant when eating away from home. Restaurants often use ingredients or cooking methods that result in the milk contamination of “safe” foods that do not normally contain milk. Individuals should always inquire about the ingredients of the meals they are ordering, and find out whether the restaurant’s kitchen properly cleans the surfaces and utensils during food preparation. These same questions should be asked when eating at a friend’s house or in any new environment.

Since an infant or young child is often too young to make dietary or medical decisions, the parents or guardian must take responsibility for keeping the child’s diet milk-free. Parents should also let their child’s school cafeteria or daycare facilities know about any special dietary needs.

It is important to note that individuals who remove milk and dairy products from the diet as a result of a milk allergy often need to take supplements or alter their diets to replace lost vitamins and nutrients – particularly calcium. Multivitamins or other nutrient-rich foods (e.g., fish, eggs) can help replace these lost nutrients. Individuals with a milk allergy should discuss their diets with their physician to learn how to properly replace missing nutrients.

Additional tips for living with milk allergies include:

  • Milk allergic individuals should take particular note that the appearance of the phrase “non-dairy” on the packaging of a food does not mean the food is milk-free. The term “non-dairy” signifies that the product is less than 0.5 percent milk by weight. This means that a non-dairy product may easily contain enough milk proteins to trigger an allergic reaction in a milk allergic individual.

  • Individuals with a milk allergy should be aware that milk and dairy items marked as “lactose-free” can still trigger a milk allergy and should be avoided. Lactose-free products contain many types of milk proteins that can trigger allergic reactions.

  • Breastfeeding infants are generally not allergic to human milk. However, a mother nursing a milk allergic infant must discontinue her own milk and dairy consumption because milk proteins can cross over into breast milk in small amounts.

There are currently a number of alternatives available to individuals with milk allergies who wish to drink milk or eat dairy. Many of these are found at health food stores or specialty food stores. These alternatives include:

  • Alternative milk. There are several kinds of milk currently available that place substitute proteins in place of cow’s milk proteins. These include:

    • Rice milk. Does not contain any of the problem proteins found in cow’s milk. However, rice milk does not always contain the same amounts of nutrients as cow’s milk, and a dietary supplement may still be necessary. This is a very safe and popular alternative to cow’s milk.

    • Soy milk. Replaces cow’s milk proteins with soy proteins. Unfortunately, many children who are allergic to cow’s milk proteins are also allergic to soy proteins. For this reason, a milk allergic individual should only try soy milk under the supervision of a physician.

    • Goat’s milk. Some individuals who are allergic to cow’s milk can tolerate goat’s milk without symptoms. However, it is not uncommon for a person to a have a cross-reaction between these two types of milk. A milk allergic person should only try goat’s milk under the supervision of a physician.

Almond milk, oat milk, sesame milk and coconut milk are milk substitutes that often cause allergies in young children and infants. They also have very low levels of calcium and are difficult to find. For these reasons these forms of milk are not considered good cow’s milk substitutes.

  • Hypoallergenic baby formulas. There are several types of baby formulas available that have been treated in such a way that the protein allergens have been partially broken down. Most milk allergic children can tolerate these formulas without symptoms. It should be noted that hypoallergenic baby formulas are much more expensive than normal baby formulas.

  • Non-dairy substitutes. There are some types of foods that commonly contain dairy proteins, but which are also produced in non-dairy forms. These foods can often be found at health or specialty food stores. Some of these dairy-free foods include:
  • Non-dairy ice cream
  • Non-dairy chocolate
  • Non-dairy cheese
  • Non-dairy yogurt

Symptom relief

There are currently no drugs available that can prevent a milk allergy from taking place. Instead, treatments are aimed at relieving allergy-related symptoms. 

Like other food allergies, allergic reactions to milk usually result in symptoms that affect the nose, throat, lungs, skin and gastrointestinal tract. These symptoms can be treated with several types of medications, including:

  • Antihistamines. Medications that provide relief for more basic allergy reactions such as hives (smooth, raised pink or white bumps that appear on or beneath the skin), sneezing, runny nose and gastrointestinal symptoms. Antihistamines directly counteract the effects of histamines, chemicals which are responsible for most milk allergy symptoms.

  • Bronchodilators. Medications that open the airways of the lungs, relieving symptoms such as shortness of breath or wheezing (a whistling or high-pitched sound that results when breathing tubes are narrowed or obstructed). They may be recommended for people whose milk allergies trigger asthma attacks or asthma-like symptoms. They are usually breathed directly into the lungs using an inhaler.

  • Epinephrine injection. A synthetic form of adrenaline that, when injected, is a powerful bronchodilator, opening breathing tubes and restoring normal respiration quickly. It is usually reserved for the most severe allergic reactions that involve anaphylaxis (generalized reaction involving two or more body systems). Most physicians recommend that individuals who are susceptible to severe milk reactions carry an injection of epinephrine with them at all times and understand how to self–administer the drug. A medical alert bracelet or necklace is also a good idea for these individuals.

  • Corticosteroids. Medications that reduce inflammation. These medications are most commonly used to treat severe allergic reactions in infants.

It is important to note that allergy medication should not be taken to prevent a reaction to a food. This action can have potentially fatal consequences. Avoidance is the only safe method of preventing an allergic reaction to a food allergen.  

Individuals should also note that antihistamines and bronchodilators are not alternatives to epinephrine and should not be used instead of epinephrine.

Questions for your doctor

Preparing questions in advance can help patients to have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctors the following milk allergy-related questions:

  1. Do my symptoms indicate a milk allergy?

  2. What methods will you use to determine if my symptoms are the result of a milk allergy or milk intolerance?

  3. Does this condition pose a danger to my overall health?

  4. What are my treatment options?

  5. Will it ever be safe to consume milk again? Are there any treatments that might allow me to safely consume milk?

  6. What should I do if I accidentally ingest food containing milk?

  7. What milk alternatives are safe for me to consume?

  8. Should I take calcium supplements?

  9. Should I take steps to avoid latex as well?

  10. Are my children likely to develop milk allergies as well? What symptoms should I watch for?

  11. Will my child outgrow his/her milk allergy?
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