Food Allergy Resources

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.

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.

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