Even trace amounts of a food can cause serious reactions in someone who is allergic to that food. Reading labels can help you avoid the offending food, but you can't avoid what you don't know about.

The Food Allergy Network and Anaphylaxis Network maintains an updated list of food notices to alert you to products that fail to declare food contents that can be allergenic, including soy, nuts, milk and eggs. Keep an eye on this list to avoid allergic reactions.