Food Allergy Tip: Top 9 Allergens While technically, you can be allergic to pretty much any food, there are 9 foods that are considered "top allergens" in the US: egg, milk, wheat, peanuts, tree nuts, fish, shellfish, soy, and sesame (newly added). The only way to have a true diagnosis of a food allergy is to have a reaction when eating that food. Many blood tests and skin tests give false positives, causing families to avoid foods when they do not need to. Current recommendations (based ...