What are food allergies? Food allergies are immediate and serious reactions that can occur after eating any food. There are some foods that more often cause issues for people: these are known as the "Top 9 Allergens". These include dairy, eggs, peanuts, tree nuts, fish, shellfish, wheat, and most recently sesame. Many times there can be confusion as to whether a food is a true allergy (Ige mediated) or possibly an intolerance/sensitivity. Testing is available to confirm or rule out IgE mediated allergy at this time. Current testing is very good at ruling out allergies, but proving allergies is not as accurate. That is why seeing an allergist to help understand your history is very important. Testing available for foods can be done via skin prick or blood. Oftentimes, your allergist may do both for more data.