Every year up to two thousand people in the United States and Canada die from anaphylaxis — a serious allergic reaction. The most common causes are allergies to peanuts, insect bites and seafood. But not all anaphylactic reactions are severe. They can be mild with subtler symptoms. And most people don’t know that if you’ve had a mild reaction in the past, you’re at risk of having a life threatening one in the future. More from Mayo Clinic on a new anaphylaxis awareness campaign.