Why are parents bagging the PB&J when packing their child's school lunch nowadays?
The answer is nuts — peanuts, that is.
In recent years, nut allergies have increased in prevalence. Today, a growing number of children —
an estimated 1 to 2 percent of the U.S. population — are allergic to peanuts and tree nuts.1
Technically a legume (bean), peanuts are a different food than tree nuts, but various studies show
there is an increased risk for having an allergy to both peanuts and at least one or more types of
tree nuts, noted Scott H. Sicherer, M.D., associate professor of pediatrics at the Jaffe Food Allergy
Institute at Mount Sinai School of Medicine, New York, NY.
In children who visit allergy clinics, most children with peanut allergies "test positive" to at least one
type of tree nut. But a positive test does not always denote an allergy; studies show that only 30 to 60
percent of children who test positive are actually allergic.
So, should your child avoid tree nuts if he has a peanut allergy, or peanuts if he is allergic to tree nuts?
There isn't one right answer.
"Many allergists suggest that a child with a peanut allergy avoid tree nuts partly because they might have or
develop a tree nut allergy," said Dr. Sicherer, author of Understanding and Managing Your Child's Food Allergies
(Johns Hopkins Press).
"Also, it can be confusing to avoid certain foods containing peanuts or tree nuts because many people get these
confused and do not recognize differences. Furthermore, products that use a tree nut might also contain peanut
and vice versa — that is, cross contact or inclusion of an avoided food might occur in products, such as cakes,
cookies and brownies," he added.
Types of Tree Nuts
However, some allergists try to individualize the best approach, taking into consideration the specific nuts/peanut
involved, dietary preferences and practical concerns. In this case, not all foods containing peanuts (if managing a
tree nut allergy) or tree nuts (if managing a peanut allergy) are avoided.
"If it is known that the nut will be tolerated, the main issue is to obtain products that do not contain the food or
foods being avoided,"advised Dr. Sicherer. "For example, it is possible to buy peanut butter that has no [tree] nuts
in it. A person with a cashew allergy might very well be safe eating peanut butter from a major manufacturer."
However, that person should be instructed to think twice about buying from
smaller companies or grocery stores that grind their own nut butters because
of cross-contact risk. They might make cashew butter then grind peanut butter
using the same equipment, thus contaminating the peanut butter.
Some families who have a child with a peanut allergy are able to allow certain
nut products into their child's diet. This must be individualized with the allergist.
Still, peanut allergy is the most common cause of anaphylaxis, and as such,
ingestion of peanuts — even if it's through cross contact in foods — should be
avoided in children with a peanut allergy at all costs.2
Once thought to be a permanent allergy, recent studies show that approximately
20 percent of young patients may outgrow peanut allergy and about 10
percent of young patients may outgrow tree nut allergies. However,
approximately 8 percent of children who removed peanuts from their
diet suffered a recurrence after successfully eating a full serving during
a supervised feeding; this risk of recurrence seems to be greater in
children who do not continue to include peanuts in their diet following
a successful challenge.3
THE BOTTOM LINE:
Even if your child is allergic to a single tree nut or only peanut, your allergist
may recommend avoidance of all types of nuts (peanuts as well as tree nuts).
But in other cases, such as with a child who is allergic to a single tree nut but
tolerates peanut butter regularly, your allergist may recommend continued
ingestion of peanuts and peanut butter as long as there is no risk they have been
contaminated with a tree nut. The bottom line is that individual cases vary, so you
should discuss with your allergist which approach is best for your child.
Beth Puliti is a professional writer for a national healthcare magazine.
REFERENCES:1. Skripak, J.M., Wood, R.A. Peanut and tree nut allergy in childhood. (June 2008) Pediatric Allergy and Immunology. 19(4):368-73.
2. Mayo Clinic. Peanut Allergy. 2008. Retrieved from the World Wide Web, www.mayoclinic.com
3. Fleischer, D.M. The natural history of peanut and tree nut allergy. (June 2007) Current Allergy and Asthma Reports. 7(3):175-81.