What Are Peanut and Tree Nut Allergies?
First grade has been a difficult parenting year for Anne. Her
6-year-old son, Justin, began eating lunch in the cafeteria with
hundreds of other students armed with their peanut butter
sandwiches, peanut butter crackers, and all those hidden peanuts in
their processed foods.
For Justin, who has an extremely severe allergy to peanuts, it
means sitting at a peanut-free table. But Justin isn't alone:
The U.S. Food and Drug Administration (FDA) estimates that 6% of
children younger than 3 years old have some kind of
, putting them at risk of an allergic reaction at home or, even
more dangerously, away from home.
Peanuts are among the most common allergy-causing foods. But
because a peanut allergy is less likely to be outgrown than
allergies to other foods, it becomes more common among older kids
and adults. It's likely that more Americans are allergic to
peanuts than any other food.
Peanuts are actually not a true nut, but a legume (in the same
family as peas and lentils). When someone with a peanut allergy is
exposed to peanuts, the immune system mistakenly believes that
proteins (or allergens) in the peanut are harmful to the body.
The immune system produces antibodies called immunoglobulin E
(IgE) that then cause allergy cells in the body (called
) to release chemicals into the bloodstream, one of which is
. The histamine then acts on a person's eyes, nose, throat,
lungs, skin, or gastrointestinal tract, and causes the symptoms of
the allergic reaction.
Peanut reactions can be very severe, even with extremely small
amounts of exposure. This might be because the immune system
recognizes peanut proteins easier than other food proteins.
The allergens in peanuts are similar in structure to allergens
in tree nuts. This may explain why almost half of people who are
allergic to peanuts are also allergic to tree nuts, such as
almonds, Brazil nuts, walnuts, hazelnuts, macadamias, pistachios,
pecans, and cashews.
People who are allergic to one tree nut are often allergic to at
least one or two other tree nuts. As with peanuts, tree nut
reactions can be very severe, even with small exposures. Research
has shown that peanuts are the #1 culprit of fatal food allergy
reactions, followed by tree nuts.
Living With a Peanut or Tree Nut Allergy
To help reduce contact with nut allergens and the possibility of
severe reactions (anaphylaxis) in someone with a peanut or tree nut
- Consider making your entire home nut-free.
- If you do allow nuts in your home, watch for
cross-contamination that can happen with utensils and cookware.
For example, make sure the knife you use to make peanut butter
sandwiches is not used in preparing food for a child with a nut
allergy, and that nut breads are not toasted in the same toaster
as other breads.
- Don't serve cooked foods you didn't make
yourself, or anything with an unknown list of ingredients.
- Tell everyone who handles the food your child eats, from
waiters and waitresses to the cafeteria staff at school, about
the allergy. If the manager or owner of a restaurant is
uncomfortable about your request for peanut- or nut-free food
preparation, don't eat there.
- Consider making your child's school lunches, as well as
snacks and treats to take to parties, play dates, sleepovers,
school functions, and other outings.
- Talk to the daycare supervisor or school principal before
your child attends. Work together to create a food allergy
emergency action plan.
- Keep epinephrine accessible at all times - not in the glove
compartment of your car, but with you, because seconds count
during an anaphylaxis episode.
With a little preparation, and prevention, you can ensure that
your child's allergy doesn't get in the way of a happy,
healthy, everyday life.
Hemant P. Sharma, MD
Date reviewed: April 2008
Note: All information is for educational purposes only. For specific medical advice,
diagnoses, and treatment, consult your doctor.
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