Is Your Breastfed Baby Allergic to Milk?

It's normal for both breastfed and formula-fed babies to get gassy and irritable sometimes. But if these symptoms often appear in your breastfed baby after feedings, your baby might be having a negative reaction to something you're eating that's making its way into your breast milk.

Molly Petersen, CLC, a certified lactation counselor at Lansinoh, says most nursing parents can eat anything they like during breastfeeding or chestfeeding and experience no issues. But occasionally, particles from food might "leak" into your baby's bloodstream through nursing, and their immune system might overreact to these unfamiliar substances.

While plenty of foods can cause allergic reactions in babies, cow's milk is one of the most common culprits. That's because of the protein molecules, which are at the root of cow's milk protein intolerance (CMPI) or cow's milk protein allergy (CMPA).

Read on to learn the symptoms of dairy allergy in breastfed babies and what to do if you suspect cow's milk protein allergy.

Symptoms of Dairy Allergy in Breastfed Babies

According to research, cow's milk protein allergy is the most common food allergy in children, affecting 1.8% to 7.5% of kids. Symptoms can vary depending on the severity of the allergy and will appear as either immediate onset symptoms (occurring within an hour of ingesting milk) or delayed onset symptoms (taking hours to appear).

Frustratingly, symptoms can occasionally appear days or weeks after ingesting, too, making it essential to talk to a health care provider to determine which type of allergy severity you're dealing with.

Complicating matters, there are two types of CMPA in infants: IgE or non-IgE mediated. IgE affects the majority of infants. Symptoms of this type are more typical allergy symptoms, occurring within a few minutes to a couple of hours after exposure.

Non-IgE-mediated more commonly presents with digestive symptoms. Restricting milk protein tends to resolve symptoms within a couple of months.

Anaphylaxis, though rare in infants, requires immediate medical attention. Health experts say to watch for the following signs:

• Difficulty breathing
• Swollen lips, tongue, throat, face
• Red, flushed appearance
• Itching
• Wheezing
• Vomiting

In addition to classic anaphylaxis signs, infants may also show non-classical signs like ear pulling, tongue thrusting, fussiness, and increased clinginess.

If your baby has symptoms of dairy allergy, visit a health care provider like a pediatrician or pediatric gastroenterologist. They may recommend eliminating dairy from your diet for a month or so to see if your baby's symptoms improve.

Risks for Developing Dairy Allergy in Breastfed Babies

Babies can develop food sensitivities that come and go throughout their first year because of their immature immune systems. An infant might also have an allergy to certain foods.

According to the National Institute of Allergy and Infectious Diseases, babies are at a higher risk for developing food allergies in the following situations:

• They have eczema
• There is a family history of food allergies
• They were born via C-section (which researchers believe affects their gut microbiome)

What to Do for Dairy Allergy in Breastfed Babies

You can still breastfeed your baby even if you suspect they have a cow's milk allergy. But to avoid passing on the proteins that trigger the allergic response through your breast milk, you must eliminate cow's milk and dairy foods like ice cream, cheese, and yogurt from your diet.

Your baby's symptoms should improve once the cow's milk completely clears from your system and your baby's system in three to four weeks. If their condition doesn't improve, consult a health care provider. They might advise eliminating other common allergens (like soy, wheat, peanuts, and eggs) from your diet and see if that helps.

Even if your baby's symptoms persist, most doctors agree there's still no reason to stop nursing since the benefits far outweigh a little intestinal inflammation in an otherwise healthy baby. After your baby recovers, your doctor may recommend slowly reintroducing cow's milk into your diet (unless your infant has a severe allergy). Simply stop again if the symptoms return.

Some good news: Your baby likely won't be allergic to cow's milk forever; many kids outgrow it. According to researchers, around 50% of babies with cow milk protein allergies will develop a tolerance by age 5.

Cow milk protein allergies are also different from lactose intolerance (an inability to digest the natural sugar in milk), which usually shows up in older children or adults.

Can Babies Be Allergic to Breast Milk?

Some parents may wonder if babies can be allergic to breast milk itself. According to Petersen, the general answer is no. "There are some extremely rare medical conditions that could cause a breast milk allergy, but it happens so infrequently that this isn't something [parents] should worry about," Petersen says.

For example, lactose intolerance is a different problem from CMPI or CMA; it occurs when an infant can not digest milk sugars in breast milk or formula. In infants, it is caused by congenital lactase deficiency, a rare but potentially life-threatening carbohydrate malabsorption disorder. It is suspected in newborns with watery diarrhea after starting breastfeeding.

Most often, the allergy is to foods the nursing parent ingested, not the breast milk itself.