Living With Food Allergies

Food Intolerance

Not all children who react to a certain food have an allergy. They may have food intolerance. Unlike food allergy, this condition doesn’t cause the immune system to react. With food intolerance, the body has trouble digesting a certain food.

Even though food allergy and food intolerance can cause some of the same symptoms, their treatments may differ. The way to prevent both conditions is to stay away from the foods that cause symptoms. Your child’s doctor can diagnose and treat the condition causing reactions to food.

There are many different causes of food intolerance. Some examples include:

  • Lactose intolerance – In lactose intolerance, the body can’t digest lactose, a sugar found in cow's milk.
  • Celiac disease – The immune system damages the small intestine when gluten protein found in wheat, rye, or barley is eaten.
  • Crohn’s disease – This chronic inflammatory bowel disease may cause diarrhea or low weight gain. It is rare in infants and toddlers.

The symptoms usually come on over time and may only happen when your child eats a lot of the food. They often involve the digestive system. 

Staying away from the foods that cause symptoms is the best treatment. Your child’s doctor may suggest other steps to prevent a reaction.

In a child with food allergies:
  • The immune system overreacts to a food that is typically harmless.
  • It creates an allergic antibody (IgE) to try to get the food out of the body.
  • IgE can develop even if the food has been eaten frequently in the past (though this is unusual).
  • There are some immunologically-driven reactions to food, known as “non-IgE mediated reactions.” These reactions are not related to IgE antibodies. Examples are reactions which occur in eosinophilic disorders like eosinophilic esophagitis (EoE). Another example is food protein-induced enterocolitis syndrome (FPIES).
In a child with food intolerance:
  • The immune system is not involved in the response.
  • There is a problem digesting the food.
  • The response is not as dangerous as an allergic reaction.

Medical Review August 2014, Updated September 2020