I am unsure if he is allergic to all related peanut family members. Brent Sue Gilbert Sue is a consulting nutritionist. For many years she worked with Earth's Best Organic Baby Food, integrating nutrition and product development. She has written numerous articles on children's health and nutrition for parenting publications. Although it can happen, it is unusual that a person allergic to one member of a particular family of foods is allergic to all of them.
Peanuts are a member of the legume family.
Most people who are allergic to peanuts can still eat other legumes with no problem. The only real way to find out if your cousin is allergic to other legumes is to challenge him with them and to look for an allergic response. If his allergy to these to foods is severe, than you should only challenge with other foods in the same family under the supervision of a doctor. You should not rely on this information as a substitute for personal medical attention, diagnosis or hands-on treatment. If you are concerned about your health or that of a child's, please consult your family's health care provider immediately and do not wait for a response from our professionals.