The peanut is not a nut. Instead, it belongs to the botanical family of legumes (peas, beans, lentils, soy, etc.).
Most peanut allergic persons can eat legumes without any problems. A low proportion of peanut allergic persons (about 5%) have, however, an allergy to other legumes such as soy or beans.
Nevertheless, 25-50% of peanut allergy sufferers develop allergic reactions to tree nuts (such as walnut, cashew, hazelnut, almond or pistachio), despite the affiliation of tree nuts to a different botanical family.