Food Allergies in Babies: Cow's Milk Allergy & Lactose Intolerance

It’s estimated that 1 in 13 children in the United States has food allergies.^1,2 A very common one is cow’s milk allergy (CMA). Some children will outgrow a food allergy over time. But this isn’t as simple as it sounds for parents wanting to provide the best and most comforting nourishment for their babies.

It’s far from an impossible situation, though. First, if you suspect that your baby has a food allergy, speak to your baby’s pediatrician. The following information on CMA in babies may also help ease your mind and guide you forward.

CMA usually develops during a baby's first year. It simply means that an infant’s immune system reacts to one or more cow’s milk proteins in infant formula, breast milk, or any food with milk-containing ingredients.

Symptoms of CMA can appear minutes to hours after a feeding. Talk to your baby’s doctor if they experience symptoms such as a rash, hives, diarrhea, constipation, and/or blood in the stool. While severe symptoms are rare, call 911 if your baby experiences trouble breathing, swelling of the tongue or throat, or loss of consciousness.

Learn more about how to spot food allergy symptoms.

Only a healthcare professional can accurately diagnose an allergy. If you suspect that your little one has a food allergy, talk to your baby’s pediatrician. They can do a full exam, take a history of all symptoms, and make recommendations specific to your infant.

CMA and lactose intolerance in babies are not the same, but they may have similar symptoms like vomiting, excessive gassiness, or diarrhea.

CMA and lactose intolerance differ fundamentally:

• Cow’s milk allergy is an immune reaction to the protein in milk
• Lactose intolerance is the inability to digest lactose, a sugar found in milk and milk products, due to a deficiency of an enzyme.

Read more about CMA and lactose intolerance.

Keep in mind that even small amounts of milk can cause a reaction in a baby with CMA. If your baby's pediatrician or allergist confirms CMA, the doctor may recommend a formula like Similac^® Alimentum^®.

Shop now to find a Similac formula that may be right for your baby.

If your baby’s pediatrician diagnoses your baby with CMA, they will likely suggest what’s called a “hypoallergenic” formula like Similac Alimentum. It’s a formula with protein that’s been extensively “hydrolyzed,” or broken down.

Shop now to find a formula that’s right for your baby.

Your pediatrician might refer you to a registered dietitian to help you learn about problem ingredients in foods and beverages and healthy alternatives to ensure your little one’s nutrition needs are being met. 

If your child has CMA, it’s important to avoid milk in all forms. You may not be able to tell if a food contains milk just from the name of its ingredients. Ingredients like galactose, ghee, and casein, for example, all contain milk.

The USDA’s food allergen label law requires a food label to state if it contains a “Top 8” allergen, such as milk. This will be identified in the ingredient list or as an allergen statement. Learn more about the Top 8 Food Allergies.

Avoid all milk-containing foods and ingredients. Though this list is not complete, here are some to look out for:  

•  Butter, butter fat, butter acid, and butter ester(s)
•  Buttermilk 
•  Casein/caseinates (in all forms) 
•  Cheese 
•  Cottage cheese 
•  Cream 
•  Curds 
•  Custard 
•  Ghee 
•  Half-and-half 
•  Lactalbumin and lactalbumin phosphate 
•  Lactoferrin 
•  Lactose 
•  Lactulose 
•  Milk (in all forms) 
•  Milk protein hydrolysate 
•  Pudding 
•  Rennet casein 
•  Sour cream and sour cream solids 
•  Sour milk solids 
•  Whey (in all forms) 
•  Yogurt

Although the protein in Similac Alimentum (Casein Hydrolysate) is derived from cow’s milk, the casein ingredient has been extensively broken down, or “hydrolyzed.” This results in a hypoallergenic formula that virtually eliminates allergic reactions in most babies who are allergic to cow's milk protein. And, it’s made to give babies the complete nutrition they need for growth and development. 

You should check with your baby’s healthcare provider before switching to any formula specially designed for the dietary management of food allergies.

If you drink cow’s milk and breastfeed your baby, there might be enough milk protein in your breast milk to cause an allergic reaction. For this reason, your healthcare professional may advise you to eliminate cow’s milk from your diet, so be sure to discuss this with your healthcare professional or your baby's pediatrician. 

Most children eventually outgrow a milk allergy and often can begin a switch to cow’s milk after they reach 1 year of age. For children who still have CMA after 12 months, it’s common to supplement with a hypoallergenic formula.

It’s important to work closely with your healthcare provider to determine when this transition should begin and to identify an appropriate milk-alternative beverage. 

References: 1. United States Census Bureau QuickFacts 2021. census.gov/quickfacts/fact/table/US/RHI225219 2. Gupta RS, et al. Pediatrics. 2018;142(6):e20181235.

Sources: Food allergies. Centers for Disease Control and Prevention.cdc.gov/healthyschools/foodallergies/ Accessed February 16, 2022.