Learn More About Your Pregnancy

Food Allergies


My baby is lactose intolerant. Is that a food allergy?


Food allergies are different from food intolerances or sensitivities. With a food allergy, your immune system causes the reaction. With a food intolerance or sensitivityyour digestive system causes the symptoms. Lactose intolerance is an example of a food intolerance that is often confused with a food allergy. Lactose is a sugar found in milk and dairy products. For lactose-intolerant people who have trouble digesting this sugareating milk products can lead to nausea, cramps, gas, bloating, and diarrhea. While lactose intolerance can cause great discomfort, it is not life-threatening. 


Many people think that food allergies and food intolerances or sensitivities are the same, but they are very different. Food allergy reactions are caused by the immune system, but food intolerance symptoms are caused by the digestive system. Lactose intolerance is an example of a food intolerance that is often confused with a food allergy. Lactose is a sugar found in milk and dairy products. For lactose-intolerant people who have trouble digesting this sugar, eating milk products can lead to nausea, cramps, gas, bloating, and diarrhea. Lactose intolerance can cause great discomfort, but it is not life-threatening. 

What Is a food allergy?

A food allergy is a medical condition in which exposure to a food triggers a harmful immune response. The immune response, called an allergic reaction, occurs because the immune system attacks proteins in the food that are normally harmless. The proteins that trigger the reaction are called allergens. 

To monitor potential reactions to new foods, introduce one new food at a time to your baby, waiting at least two or three days before starting another. The symptoms of an allergic reaction to food can range from mild to severe.  

Mild symptoms include: 

  • Nose: itchy or runny nose, sneezing. 
  • Skin: a few hives, mild itch. 
  • Gut: mild nausea or discomfort. 

Severe symptoms include:

  • Lungs: shortness of breath, wheezing, repetitive cough. 
  • Heart: pale, blue, faint, weak pulse, dizzy. 
  • Throat: tight, hoarse, trouble breathing/swallowing. 
  • Mouth: significant swelling of the tongue or lips. 
  • Skin: many hives over body, widespread redness. 
  • Gut: repetitive vomiting or severe diarrhea. 

Symptoms can involve just one area of the body, or more than one area.

  • A mild reaction involves a mild symptom that affects only one area of the body. If you notice one mild symptom in your baby after introducing a new food, stop serving that food and talk to your provider at your next well-baby appointment about next steps. 
  • A reaction that involves any severe symptom is a severe reaction. Call 911 immediately. 
  • A reaction that involves mild symptoms in more than one body area is also a severe reaction and requires medical attention immediately. 

Severe reactions can quickly turn into anaphylaxis, a medical emergency that can be life-threatening that can result in difficulty breathing and even deathTreat severe reactions immediately with epinephrine if it’s available and contact emergency services. If you don’t have epinephrine on hand, call 911. 

Foods that can cause food allergies

Although nearly any food can trigger an allergic reaction, there are nine foods that cause most reactions.  

  1. Cow’s milk. 
  2. Egg. 
  3. Peanut. 
  4. Soy. 
  5. Wheat. 
  6. Tree nuts (such as walnuts, pistachios, pecans, cashews). 
  7. Fish (such as tuna, salmon, cod). 
  8. Shellfish (such as shrimp, lobster). 
  9. Sesame. 


The good news is that food allergies can be outgrown, including most (but not all) allergies to egg, milk, wheat, and soy. Some allergies are more persistent. For example, only 1 in 5 children outgrow a peanut allergy, and fewer outgrow allergies to other nuts or seafood. Your provider or allergist can perform tests to track your child’s food allergies and watch to see if they are going away. 

Receiving a food allergy diagnosis for your child can be overwhelming. There is a lot to learn, and it can be tough to know where to start, but you are not alone. There are thousands of other people just like you in the food allergy community who can help you and your family live well.