True breast milk allergy is rare. One of the only recorded cases was described by pediatrician Subhash Sood in the 1965 "Indian Journal of Pediatrics." In the 2008 "Clinical and Experimental Allergy," researchers discovered that infants allergic to cow's milk may develop sensitivities to breast milk proteins too, a phenomenon known as cross reactivity. Cross reactivity occurs when antibodies for one type of antigen react to similar compounds as if they were the original allergen. In most cases, however, infants react to dairy proteins that have migrated from the mother's diet into her breast milk.
Milk Allergy vs. Lactose Intolerance
True milk allergy differs from lactose intolerance. Allergies are immune system reactions that involve many organ systems and can result in serious effects. Food intolerances generally affect the gastrointestinal tract alone.
Lactose is a sugar found in both breast milk and cow's milk. It boosts absorption of calcium and iron, promotes healthy gut flora and is used in brain development. Milk allergy involves reactions to milk proteins.
Symptoms
Signs of lactose intolerance include bloating, diarrhea and gas.
Milk allergy symptoms, to breast milk or cow's milk, may occur immediately or develop over time. Immediate reactions to milk include hives, wheezing and vomiting. Symptoms that may develop over time include blood in the stool, loose stools, cramps or colic. Coughing and wheezing, a runny nose and watery eyes may also occur. An itchy rash may develop, especially around a baby's mouth.
Anaphylaxis is the most severe allergic reaction. Signs of anaphylactic shock include constriction of airways and throat swelling, a drop in blood pressure, facial flushing, itching and shock.
Mother's Diet
Breast milk is still the best source of nutrition for your infant and may help prevent your child from developing other kinds of allergies later in life. When you ingest dairy products, milk proteins appear in your breast milk and can cause allergic reactions in your child. If you or your child must switch to a milk-free diet, your doctor can help you be sure to get essential nutrients such as calcium, vitamin D and riboflavin.
Milk allergy is among the most common of food allergies. One percent to 7.5 percent of infants are allergic to milk protein in cow's milk according to Kids Health.org. Eggs, fish, peanuts, shellfish, soy, tree nuts, and wheat are other common food allergies. A child allergic to one food is likely to be allergic to other foods, too.
Dietary Sources of Milk
The most obvious sources of milk proteins are butter, cheese, ice cream, milk and yogurt. Not-so-obvious sources of milk proteins exist in artificial butter or cheese flavoring, candies, casein and fat-replacement products. Milk proteins are also present in hydrosolate, protein powders and any ingredient that starts with the prefix "lact."
Don't rely on products labeled "non-dairy" and ask how your food is prepared in specific terms when you're eating out.
References
- Mayo Clinic: Milk Allergy; August, 2011
- "Indian Journal of Pediatrics:" Human Milk Allergy; Subhash C. Sood and Harjit Singh; 1965
- Clinical & Experimental Allergy: Sensitization to Human Milk; U. Schulmeister et al; January, 2008
- Dr Jen 4 Kids: Pediatric Myths: Formula; Jennifer Thomas, MD; 2011
- Kids Health.org: All About Allergies; 2011
