Eggs are in the flu vaccination. The vaccine is incubated in eggs. That is how it is made. With that little bit of knowledge it helps to make it easier to comprehend that eggs can be anywhere. Our modern society can strip, pull apart, recombine, mix and mash individual components of the egg to be used in a vast variety of ways from medications to cosmetics.
Some foods are “washed” in egg whites such as some alcoholic and soft drinks. Eggs can be used to coagulate, bind or emulsify making it likely that they can be in just about anything processed that a person could consume. Eggs may be in the bologna from the deli or any other processed meat. If the food is a dressing for salads or a sauce, there is a high likelihood that it contains parts of eggs.
If there is a concern that there is an egg intolerance and there is a food that is well liked but is causing symptoms even though there is no indication it contains eggs, ask the manufacturer. Look on the back label for a toll-free number for consumer inquiries.