Allergies and food allergies tend to run in families, it is impossible to predict whether a child will inherit a parent’s food allergy or whether siblings will have a similar condition.
Some research does suggest that the younger siblings of a child with a peanut allergy will also be allergic to peanuts. The symptoms of a food allergy can range from mild to severe. Just because an initial reaction causes few problems doesn’t mean that all reactions will be similar; a food that triggered only mild symptoms on one occasion may cause more severe symptoms at another time.
Food Allergy. (n.d.). Retrieved June 06, 2016, from http://acaai.org/allergies/types/food-allergies