Nature of Peanut, Tree Nut Allergies in Kids Explored in Study

More than a quarter of the kids who are allergic to peanuts are also allergic to tree nuts, such as almonds and walnuts, according to a study by researchers at Mount Sinai Medical Center in New York.

The study, perhaps the most comprehensive concerning the rising incidence of peanut and tree nut allergies, also found that the average age of initial discovery for the allergies is age 2 for peanuts and age 5 for tree nuts. And the study, which was published in the July electronic edition of the journal Pediatrics, shows that 89% of the allergic reactions occur on the skin, 52% occur in the respiratory system and 32% occur in the gastrointestinal tract.

Of the 122 children who were studied by the research team, 68 reacted only to peanuts - which are legumes and not nuts - and 20 only to the tree nuts. And while only about a quarter of the kids were allergic to both, doctors believe parents should play it safe - the allergies can, in extreme cases, result in death.

"Although it may be overly restrictive, we and others advise complete avoidance of TN (tree nuts) by PN (peanut)-allergic children, except for any particular TN that was tolerated previously," the researchers write. "Reasons for this recommendation include the concern that TN sensitivity appears to be severe and lifelong, that there is a potential for cross-contamination of TN products with PN and, finally, that it often is difficult to identify specific nuts in various processed foods."

Indeed, about 55% of the kids allergic to peanuts and 30% of those allergic to tree nuts experienced accidental exposure to them. Most commonly, those accidents occurred at schools, and were a result of either sharing food with friends, hidden ingredients in their own food, cross- contamination with food products containing the allergen, and school craft projects using peanut butter. The researchers say accidental exposure also occurs at home and in restaurants - particularly Asian restaurants in which peanut oil is sometimes used as a frying agent.

About 83% of the kids with either peanut or tree nut allergies were breastfed - above the average of about two-thirds of children. The researchers also found that more than 90% of the breastfeeding mothers ate either peanuts or tree nuts during the lactation process.

So far, there is little medical science has been able to do for the people with the allergies; immunizations developed thus far have side effects more dangerous than the allergies themselves. "The only current treatment for these allergies is strict avoidance of the offending food and prompt recognition and treatment of reactions," the researchers write. "These findings emphasize the need for education of families, patients, caregivers and health care workers in PN and TN avoidance and treatment of reactions."