What Causes Food Allergies?

Food allergies happen when the immune system reacts to certain foods, like peanuts or shellfish, as if they are dangerous invaders. Your body makes antibodies to proteins on the food called antigens, causing an immune response. Antigens that cause an immune response are called allergens. 

Children and Food Allergies 

Scientists aren’t certain why some children develop food allergies. One reason could be that some young children aren’t exposed to certain foods while their immune systems are still growing and developing. For example, research suggests that early introduction of peanuts could lower the risk of peanut allergies in children. This was highlighted in a recent study called Learning Early About Peanuts (LEAP), which found that children who eat peanuts at a young age are less likely to develop a peanut allergy. 

Scientists think this could be due to how the child is first exposed to peanuts. If peanuts are “invited” in through the mouth, your immune system learns to tolerate them. But if your first encounter with peanut protein is through the skin, the immune system may see them as intruders and can develop an allergy.  

For children with uncontrolled eczema (also known as atopic dermatitis), whose skin barrier is disrupted, the chance of developing allergic immune responses to food proteins through the skin is higher than the general population. It’s important to keep in mind that this has not been studied for all allergens (just the peanut so far). It is important to partner with your child’s pediatrician before you give your child potentially allergenic foods, particularly if there is a higher risk of allergies in your family.