Peanuts are one of the most severe food allergens. They often cause life-threatening reactions. There's more people with this allergy than any other allergy. Peanuts aren't actually nuts...they're a legume. They're in the same family as peas and lentils. But I'm not allergic to peas of lentils. Half of those allergic to peanuts are also allergic to tree nuts, such as almonds, walnuts, pecans, cashews, and often sunflower and sesame seeds. But I'm not allergic to those either...but I stay away from them just incase.