Common food allergy
If you are allergic to eggs, then processed foods are going to be a real concern for you. Also, avoiding food prepared by restaurants and catering services could be a necessary strategy, depending on the severity of your allergy. Egg allergy can be a small annoyance or a life-threatening chronic concern.
At issue with egg allergy is the fact that the food could contain egg and that egg be unrecognized or undetectable by sight or smell. Some foods have a distinctive appearance or taste so that the person who is allergic will know immediately. Eggs, however, are often added to dishes and will not be immediately visible. Eggs can be used as "binders" in many foods. It doesn't have to be a quiche to have egg in it.
Another problem is the presence of eggs in common items like condiments. Egg allergies can pose significant problems because eggs are used in every day condiments such as mayonnaise or salad dressing. While food may be prepared to carefully exclude offending ingredients directly, people will often forget that common condiments will also contain allergens. Many people cite this problem with well-meaning family members who don't realize that an egg allergy means that the ingredients within ingredients also have to be checked!
If an egg allergy is life threatening, "cross-contamination" becomes a significant challenge. Cross-contamination refers to a normally allergen-free dish becoming contaminated with a small amount of allergenic protein from being prepared on a common surface or cooked in a common ingredient (such as items being fried in the same frying oil, as is common at many fast food restaurants). In fact, you can even have cross-contamination occur from simple food handling, if a food preparer has handled an allergenic ingredient and then handled food that is being prepared for the allergic consumer. This is why buying your food from a restaurant or as a prepared dish is always more risky than making and eating your own.
It is up to the allergic person to know the degree of risk that they face if they consume a prepared meal and ingest some egg. Also, keep in mind that increased exposure is one of the routes to a more severe allergy.