There are around 32 million Americans who have food allergies, according to the group Food Allergy Research & Education (FARE).

Food allergies typically fall into one of eight categories: milk, eggs, peanuts, tree nuts, soy, wheat, fish or shellfish.

It is estimated that 5.6 million children under the age of 18 are allergic to at least one of these types of food. So what should new parents know?

“We should be introducing allergenic foods at a much younger age,” says allergy and immunology Dr. Ellen Sher.

Sher says that this allows children to build a tolerance to these allergens. She says that children may actually be at an increased risk for developing an allergy if they are not exposed early in life.

Sher says that it is possible to outgrow a food allergy, depending on the food.

“With milk and egg allergy, it’s very common that these food allergies will be own grown,” she says.

But Sher says, “Peanut allergy, tree nut allergy and shellfish allergy, it is actually much less common.”

And what about adults who seem to develop problems with foods that did not bother them as children?

“A lot of times that is more of a food intolerance than an allergy,” she says.

FARE says that more than 170 foods have been reported to cause allergic reactions. The group also says that allergies to sesame is also an emerging concern.