What Are Food Allergies?1


A food allergy is a reaction of the body's immune system to proteins found in food. For some children, eating certain foods causes the body to make an antibody that triggers the allergic reaction. Repeated exposure to a food allergen can cause the allergic reaction to become more severe. Remember, food allergies in babies are a serious and potentially life-threatening medical condition.

If your baby has a food allergy, she’s not alone. In fact, it’s estimated that 4 out of every 100 children in the US have food allergies.1 Fortunately, some children can outgrow their food allergy over time by completely avoiding the food allergen. For others, it may be lifelong. If you suspect a food allergy, speak to your baby’s healthcare professional.

Common Food Allergy Symptoms

  • Rash or hives
  • Nausea/vomiting
  • Stomach pain
  • Diarrhea or blood in stools
  • Itchy skin or eyes; runny nose
  • Shortness of breath
  • Swelling of the airways to the lungs
  • Anaphylaxis

Top 8 Food Allergens

cow milk
tree nuts

What Is Cow’s Milk Allergy (CMA)?

Cow’s milk allergy in infants is most likely to develop during a baby's first year. When a baby is allergic to milk, her immune system overreacts to milk protein in breast milk or formula. Symptoms vary and typically appear minutes to hours after a feeding.

Symptoms of cow’s milk allergy in babies can be as mild as a rash or a runny nose, or they can be extremely dangerous. When you're caring for an infant who doesn’t speak yet, trying to figure out if she is allergic to milk can be tricky. Knowing food allergy symptoms can help.2

It’s especially important to speak to your baby's doctor if you suspect a food allergy. The doctor will be able to do a full exam, take a history of all symptoms, and even refer you to an allergist.

Is It CMA or Lactose Intolerance?

CMA and lactose intolerance in babies are not the same. They may have similar symptoms, such as nausea, vomiting, stomach cramps, or diarrhea, making it tricky to distinguish between the two.3

  • A food allergy, such as CMA, is an immune reaction to the protein in milk.
  • Lactose intolerance is the inability or insufficient ability to digest lactose, a sugar found in milk and milk products. It is caused by a deficiency of the enzyme lactase.
  • Lactose sensitivity, or sensitivity due to lactose, may be caused by various conditions.

Symptoms of lactose intolerance and lactose sensitivity can be uncomfortable for your baby, but it’s harmless. Food allergies in babies, on the other hand, can be harmful and might also cause additional symptoms. There could be some mild reactions, like flushing, rash, hives, or a runny nose. Other symptoms can be much more serious, like trouble breathing, wheezing, swelling of the tongue and throat, and even loss of consciousness.

To stay safe, avoid feeding all foods with milk-containing ingredients to an infant who has a milk allergy.3

Parents must see a healthcare professional to diagnose an allergy. If your healthcare professional confirms that your child has a lactose sensitivity or lactose intolerance, ask them about Similac Pro-Sensitive™ or Similac Pro-Total Comfort™.


  1. What is a food allergy? There are different types of allergic reactions to foods. Kids With Food Allergies website. http://www.kidswithfoodallergies.org/page/what-is-a-food-allergy.aspx. Accessed April 30, 2018.
  2. Does my baby have a cow’s milk allergy? Abbott website. http://www.nutritionnews.abbott/healthy-moms-babies/does-my-baby-ha-----ve-a-cow-s-milk-allergy-.html. Accessed April 30, 2018.
  3. Ask the expert: milk allergy or lactose intolerance? Abbott website. http://www.nutritionnews.abbott/healthy-moms-babies/ask-the-expert--milk-allergy-or-lactose-intolerance-.html. Accessed April 30, 2018.

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