I would like to say that I look at the ingredients for every package of food that I purchase. However that is not always practical.
This page is a place for people to post information about items where the ingredients have changed in a way that may include different allergens.
For an example, I have noticed:
M&M Chocolate Candies in specialty holiday flavors now has a warning at the bottom “Contains Milk and Soy. May contain Peanuts, Tree Nuts and Wheat.” The Milk and Soy ingredients were always there. The others are new. I do not know if there has always been the possibility of contamination or if this is just more likely recently.
I do not get notified by the companies involved so if you see something that has changed and surprised you, let me know. Do not rely on this list always read your labels as you could be the first to find something changed!