Preventing Food Allergy in Children |
Food allergies affects about 4% of the children in the United
States, and those numbers appear to be growing.
An allergy to peanuts can lead to anaphylaxis and even death.
Recently a panel of experts published a report that indicates
infants can be given potentially allergy-causing foods as a way to
prevent food allergies.
Intended for pediatricians and other health care providers, the
guidelines are published in the Journal of Allergy and Clinical
Immunology.
But the real purpose of the guidelines is "to spread the word." .
What are the guidelines?
The recommendations are "really simple and straightforward," as the
intention is to answer the typical questions of family physicians.
Recommendations fall into three categories.
The first category includes children who are believed to be most
likely to develop a peanut allergy: infants who have severe asthma,
egg allergy or both. Parents can either introduce these children to
peanut-containing food at 4 to 6 months or get a reference to an
allergist who will give the child a skin prick test or a blood test
to see whether the infant is allergic to peanuts.
If not allergic, parents should follow the recommendation of
introducing peanut-containing foods at 4 to 6 months. However, if
the infant is allergic, parents should refrain.
The second category includes children with mild to moderate eczema;
less likely to have an allergy, these infants should be introduced
to peanut-containing foods about 6 months of age.
Finally, the third category belongs to children with no eczema or
food allergies and no family history of such. These children can
either be fed peanut-containing foods or not at any age, based
purely on family and cultural preference.
If it's severe, go to an allergist. If it's not severe, give
peanut-containing foods, but give it at 6 months. For infants with
no family history of allergy or no food allergies themselves. Just
give them whatever foods the family prefers.
"Something as simple as that ... we think will go a long way in
decreasing the incidence of peanut allergy in society," the report
said.
A study to snack on
The trial is significant because it was "the first and only large,
randomized prevention trial for peanut allergies," and so the
results are considered "definitive," said Dr. Jerry Nepom, director
of the Immune Tolerance Network. The network developed the trial,
which was led by professor Gideon Lack.
In Israel, there's a custom of feeding infants a popular peanut
butter snack "as soon as they possibly can," he said. "And they
found out that the infants in Israel had a remarkably lower
incidence of peanut allergy than infants in the UK -- even Jewish
infants in the UK whose parents did not follow the custom" of giving
infants the peanut snack.
From this largely unscientific observation, Nepom and his colleagues
constructed a scientific study.
"We designed the trial and ran the trial because there was a clear
public health need and there was a lot of rationale for it," Nepom
said.
More than 600 children participated in the study, and each was
randomly assigned to one of two groups. One group consumed low-dose
peanut-containing food three times a week, starting in the first
year of life and continuing to the age of 5. The other group
abstained from peanuts for the first five years of life.All the
children participating in the study were at high risk of peanut
allergy due to family history or having eczema or egg allergy
themselves, said Nepom.
At age 5, the children in both groups were given peanuts and
observed, Nepom said: Eighteen percent of the children who had been
avoiding peanuts had a peanut allergy at age 5, compared with only
1% of the children who had been introduced to peanut butter or Bamba
early in life.
"This showed that early introduction of peanut flour had over 80%
prevention effect," Nepom said.
Calling them back a year later and repeating the challenge,
the earchers discovered that all the kids who did not have an
allergy at age 5 still did not have peanut allergy at age 6.
"Of course, we're extremely gratified that the result came out so
definitively," Nepom said, adding that he's also pleased the data
were used to support the new guidelines."
Naturally, the next question is: Can a similar technique prevent
other common allergies, such as milk, or even uncommon ones?
Though there have been small studies -- none so rigorous as this one
-- that suggest this will work for other food allergens, there has
not been a large, randomized, controlled trial to "really nail it
down," Nepom said. "Without that kind of data and evidence-based
practice, we have to say it's the logical next step, but without
testing we cannot issue hard and fast guidelines for other
allergies."
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