Milk Allergy

Milk: It’s healthy, good for bone strength, and also available in chocolate or strawberry. But for children, cow’s milk is also one of the most common food allergens.

Individuals with an allergy to cow’s milk must be highly vigilant because milk proteins are found in a wide range of foods where they might be unexpected. For example, some canned tuna fish and nondairy products contain casein, a milk protein that is also used in some meats. Beverage mixes and body building and energy drinks commonly contain whey, another milk protein. Milk protein has also been found in some chewing gums. The Food Allergen Labeling and Consumer Protection Act of 2004 states that all packaged foods labeled on or after January 1, 2006, must list – in plain language – whether a product contains one of the top eight food allergens: milk, egg, fish, shellfish, tree nuts, wheat, peanuts and soybeans, but it’s still important to check labels.

Cow’s milk allergy can occur in two ways: as IgE-mediated milk allergy and non-IgE-mediated milk allergy. Most children who are allergic to milk experience IgE-mediated allergy, which involve IgE antibodies. Typical milk allergy symptoms involve hives, vomiting, or even anaphylaxis, a severe and sudden reaction that may cause death. Non-IgE-mediated milk allergy involves the gastrointestinal tract and may present in early infancy with blood in stool.

Cow’s milk is a fairly easy ingredient to substitute. Most recipes can be just as successful by substituting the equivalent in water, juice, or soy or rice milk. 

Milk Allergy in Children

Cow’s milk allergy is estimated to affect about 300,000 children under the age of 3 in the United States. Although it was formerly believed that the vast majority of children would outgrow this allergy by age 3, recent studies contradict this theory. Less than 20 percent of children enrolled in one study had outgrown their allergy by the age of 4. Still, approximately 80 percent of children with milk allergy will outgrow it by the age of 16.

Frequently Asked Questions

Are some individuals allergic to cow’s milk able to tolerate foods containing heated milk?

Studies have shown about 75 percent of individuals with milk allergy can tolerate foods that contain extensively heated milk, such as a baked muffin. However, people with milk protein allergy should consult with an allergist before determining whether they should avoid milk completely, independent of whether it has been extensively heated.

What is the difference between milk allergy and lactose intolerance? How can I tell which one I have?

Individuals with milk allergy experience reactions that result from immune-mediated responses to the proteins found in milk. Typical reactions of this type of allergy involve hives, vomiting, or even anaphylaxis, a severe and sudden reaction that may cause death. People who have lactose intolerance cannot digest the milk sugar (lactose) because they have a deficiency of lactase, the enzyme in the lining of the gut required to metabolize lactose. The lack of this intestinal enzyme leads to reactions such as abdominal gas, diarrhea, or abdominal cramps. Milk allergy and lactose intolerance are not related.

What is the best formula for babies with milk allergies?

If your infant is allergic to cow’s milk, talk to his or her pediatrician about which formula to use. Often, an extensively hydrolized elemental formula or a casein-hydrolysate formula is recommended, as the proteins in these formulas have been extensively broken down. Alternatively, your infant’s doctor may recommend a soy-based formula.

Reprinted with permission from the American College of Allergy, Asthma & Immunology