Why is the peanut allergy an epidemic that only seems to be found in western cultures? More than four million people in the United States alone are affected by peanut allergies, while there are few reported cases in India, a country where peanut is the primary ingredient in many baby food products. Where did this allergy come from, and does medicine play any kind of role in the phenomenon? After her own child had an anaphylactic reaction to peanut butter, historian Heather Fraser decided to discover the answers to these questions.