Although “peanut allergy” isn’t exactly synonymous with “food allergy,” peanut allergy exemplifies the food allergy phenomenon in a nutshell. It functions as a key to understanding just how common food allergy is, how the prevalence of food allergy has risen, and just how deadly a food allergy can be.

Because peanut allergy typifies food allergy, researchers have focused a great deal of research on it over the past 20 years, seeking answers to these most fundamental questions:

• Why are peanut reactions so serious?
• Why do you get peanut allergy?
• Why is peanut allergy becoming more common?
• What can be done to prevent peanut allergy?
• Can doctors treat peanut allergy?

The whole purpose of this articles is to address these questions for any food allergy you have and express the answers in a way that assists you in living well with your food allergies on a daily basis. With peanuts, however, the third question, “Why are peanut reactions so serious?”.

A handful of proteins are primarily responsible for triggering allergic reactions, because your immune system sees them as the bad guys. Peanut proteins — specifically the three proteins fondly referred to as Ara h 1, Ara h 2, and Ara h 3 — look more like the bad guys than most other food allergens. (A protein is made up of a long string of building blocks called amino acids, which are folded into all sorts of shapes and sizes. No two proteins look exactly alike.)

Without becoming too technical, what makes peanut proteins so capable of stimulating an allergic reaction is the way in which they’re folded. (Molecular size and stability may also be contributing factors.) Peanut proteins are folded in such a way that the protein pieces responsible for stimulating the immune system are very much exposed, rather than concealed inside the molecule.

This gives the molecule a high profile that’s easy for your immune system to recognize. Although peanut proteins are easy for your immune system to recognize, researchers still do not know why some people’s immune systems react to them so strongly. Do they look like something more sinister?

Hopefully, future research can provide the answer. Most people with peanut allergy have IgE antibodies against all three highprofile peanut proteins — Ara h 1, Ara h 2, and Ara h 3, so when you eat a peanut, you’re often getting a triple dose of allergen.

Not all people with peanut allergy have life-threatening reactions to it, but this lowly legume, more than any other food allergen, is capable of causing severe and sometimes fatal reactions. Moreover, peanut can trigger these reactions with exquisitely small exposures.

In studies of fatal food reactions, peanut and tree nuts are responsible for the vast majority of all such reactions. If you have peanut allergy, remain on the lookout for even trace amounts of peanut, which unfortunately shows up in a wide variety of foods.