Science stumped on food allergy trend in children

The Seattle Times ^ | November 29, 2005 | BRUCE TAYLOR SEEMAN

[neverdem]

Newhouse News Service

Multiple-choice question: Why are more American kids allergic to foods, particularly peanuts?

A) Their immune systems are confused by increasingly clean homes.

B) Nervous parents wait too long to feed their children peanuts.

C) We roast peanuts rather than boil them.

D) Maybe one of the above, and/or something else.

Unfortunately, the answer is "D."

One study estimates American children's rate of allergy to peanuts and tree nuts (like walnuts and pecans) — about 1 percent of those under age 18 — has doubled in recent years. No one can say why.

But whatever biological mysteries are at work, U.S. children are more likely to be allergic to peanuts than kids in China, in Israel and in many underdeveloped nations, experts say.

"It's a moving target," said Dr. Robert Wood, a pediatric immunology professor at Johns Hopkins University. "The numbers may be different by the time the next study gets done."

Deaths from allergic reactions to food are not officially counted, but studies suggest 150-200 fatalities a year, experts say. Case studies of 32 food-allergy deaths during 1994-99 showed that most victims died of reactions to nuts, most had asthma, and 13 were under 18 years old.

Though rare, deaths from food allergies can occur with shocking caprice.

New law on allergies

On Jan. 1, a new federal law goes into effect requiring food manufacturers to use simple language — milk instead of "caseinates," egg instead of "albumin" — in food products' ingredients lists. The law will apply to peanuts, tree nuts, milk, eggs, fish, wheat, soybeans and crustaceans (such as shrimp and crabs). Proteins in these foods cause about 90 percent of allergic reactions. Studies of peanut, tree-nut, fish and shellfish allergies suggest 11.4 million Americans, or about 4 percent of the population, have food allergies, according to the Food Allergy & Anaphylaxis Network. Ten years ago, scientists believed less than 1 percent of the population was affected.

In 2003, about 1,800 children under 18 were hospitalized due to food allergies, according to a federal estimate. That number had increased only slightly during the preceding decade, but researchers say many allergic episodes go uncounted when hospitals misclassify them.

"The data are not clear enough to say what the true rate of increase has been, but we would be very comfortable saying the rate of food allergy has truly increased," said Wood.

The only treatment for a severe allergic reaction is a shot of epinephrine, a hormone that relaxes the airways of someone struggling with a life-threatening allergic response.

On Jan. 1, a new federal law goes into effect requiring food manufacturers to use simple language — milk instead of "caseinates," egg instead of "albumin" — in food products' ingredients lists. The law will apply to peanuts, tree nuts, milk, eggs, fish, wheat, soybeans and crustaceans (such as shrimp and crabs). Proteins in these foods cause about 90 percent of allergic reactions.

Meanwhile, some advocates are pushing for federal guidelines for schools to create emergency action plans for allergic students.

In well-prepared schools, administrators have assembled teachers, parents, a school nurse and others to discuss how to handle emergencies and how to make a school safe, said Anne Munoz-Furlong, founder of the Food Allergy & Anaphylaxis Network, a group advocating more protections. "Nut-free" zones are becoming more common on school lunch tables.

Even highly sensitive peanut-allergic children are unlikely to experience a severe reaction from casual external contact with peanut butter, research has shown. Soap and water effectively remove the allergen from surfaces such as tabletops, while disposable wipes work well with hands.

But reactions do occur, most often when a child unknowingly eats something containing an allergen. Serious problems result when a school's files contain nothing from a child's doctor about a condition, what symptoms to look for and how and when to give medication.

"A child eats something, thinks it was safe, but they have a reaction," Munoz-Furlong said. "They're sent to the office, the office staff calls the parents. Or the child has asthma, and they give her an inhaler. The reaction gets completely out of control, and when you bring epinephrine into the picture, it's too late."

An allergic reaction occurs when the body mistakenly identifies something as an invader and activates a portion of the immune system. People with hay fever, for example, overreact to the inhalation of pollen. The same process occurs in food allergies, with protein acting as the trigger.

In someone allergic to peanuts, for example, the body senses a specific protein has attached to cells in the body. To "protect" the cells, it sends out special antibodies called immunoglobulin E, or IgE. When IgE reaches the cells, it causes them to release histamines and other chemicals that may cause itching, nausea or restricted breathing.

In trying to explain the increase in allergies, many scientists have embraced the "hygiene hypothesis." It holds that some people's immune systems have gone out of whack because America's increasing cleanliness has changed the behavior of IgE.

The central role of IgE is to help fight infections. But as America has become more sanitary, and as antibiotics have cut down on infections, IgE has less work to do, making it restless and prone to attack new things.

"The more [IgE] is left 'unbusy' because we're not being exposed to germs early in life, the more it could direct its attention toward allergies," said Wood.

Some data support this idea. Allergy rates are lower in many underdeveloped nations, perhaps because the immune systems of those who live there are constantly exercised.

But the hygiene hypothesis, which would apply to all kinds of allergies, doesn't explain everything.

"It's not clear that it's the whole story," said Dr. Marshall Plaut, chief of allergic mechanisms at the National Institute for Allergy and Infectious Diseases.

Doctors have successfully "desensitized" patients with allergies like hay fever by injecting them with small but increasing doses of pollen. Such "immunotherapy" often causes severe reactions when tried against food allergies — an effect scientists are trying to understand and avert.

Mindful of the hygiene hypothesis, researchers also are studying whether exposing children earlier in life to peanuts and other potential allergens may properly prepare their immune systems.

Peanut allergy rates in Israel are low compared with the United States, and some suspect that's because many Israeli children eat peanut snacks earlier and more often than American children do.

"It could be the hygiene hypothesis," Munoz-Furlong said. "It could be the way peanuts are processed. In China they boil them, and we roast them. Or, it could be how they introduce it; in this country, we wait until the third birthday. In Israel, it's typically before the first birthday."

[neverdem]

CHRISTOPHER ROSSI / NEWHOUSE NEWS SERVICE
Second-graders Isabel Parks, left, and Alyssa Luz-Ricca eat lunch in a "nut-free zone" provided by their elementary school in Arlington, Va. Some advocates are pushing for federal guidelines for schools to create emergency action plans for allergic students.

DAVID BITTON / COLORADO SPRINGS GAZETTE
A sign is posted in the gym at Kilmer Elementary in Colorado Springs, Colo., to remind students not to take peanut products into common areas at the school to help protect students who are allergic. © 2005 The Seattle Times Company

More information

The Food Allergy & Anaphylaxis Network (FAAN) Web site: http://www.foodallergy.org

[Windsong]

LOL...they've truly lost it..

[LucyT]

Kiss fatal for girl, 15

Sat, November 26, 2005
By CP

SAGUENAY, QUE. -- A 15-year-old girl with a peanut allergy has died after being kissed by her boyfriend, who had eaten peanut butter.

The girl died this week, a few days after being kissed.

The teenager, who lived in Saguenay, about 250 kilometres north of Quebec City, received a shot of adrenalin immediately after being kissed, but did not recover.

http://lfpress.ca/newsstand/News/National/2005/11/26/1324591-sun.html

[writer33]

I guess it's time to start serving vanilla wafers for lunches at schools. We just can't take the chance.

[Mo1]

FYI - since you were asking about this last night

[colorcountry]

Perhaps it's because we've been playing with our immune systems since the 40's/50's.

Innoculations have probably saved thousands, if not millions of lives. We've tricked our systems into fighting viral and bacterial invaders though innoculations. Maybe this is a long-term consequence.

I said MAYBE.

[CJ Wolf]

In trying to explain the increase in allergies

How about before we figured out how to save these unfortunate souls with food allergies, they died. Removing them from the gene pool. Now we save them and allow them to reproduce and make more poor little souls with potential food allergy. Or 2: There are more people now that know what a food allergy can do then before, hence an increase in reports.

[norraad]

..either way, pass the peanut butter please.

[LibFreeOrDie]

Peanut Allergy May Have Genetic Link

http://allergies.about.com/cs/research/a/blpeanutgenetic.htm

Transplant Patient Inherits Nut Allergy

http://allergies.about.com/library/weekly/aa013103a.htm


Peanut Allergy: Where Do We Stand?

http://www.allerg.qc.ca/peanutallergy.htm

[mikegi]

This food allergy issue has gotten out of control. My wife had trouble supplying a snack for our daughter's preschool class because of the restrictions (take a look at how many products contain peanut or other nut oil in their processing).

I've read about the hygiene argument and it seems possible. I'm not a biologist and did not sleep in a Holiday Inn Express last night, but I've known several kids with peanut allergies. My parents' generation, who are now in their 70s, rarely had food allergies and even pollen allergies. I also noticed that many of them never wore glasses until they became farsighted with age. Of course, this is all anecdotal. I'd like to see something more scientific.

[CJ Wolf]

I feel for the poor kids and people that suffer from this. Maybe it's a miner's canary, but maybe it's just a glitch in how they were programmed. I hope they can fix it, I certainly don't want any of them to die.

[goodnesswins]

Early man probably ate LOTS of nuts, seeds, etc.....and some probably died because of the nuts.....just like some people who have bee sting allergies....well, sorta. Now, lots of babies survive who may not have otherwise, as others here have alluded....

[FreedomCalls]

My parents' generation, who are now in their 70s, rarely had food allergies and even pollen allergies.

On the other hand a lot of them died either in infancy or while they were toddlers. Did they even recognize those deaths as possibly allergy-related? Maybe it's just that children are living with an allergy in the 2000s that would have killed them in the 1930s and so it's just more visible.

[Arizona Carolyn]

When you understand what vaccinations are doing in the immune system I'm convinced there is a link. Purdue recently published the results of a study on vaccinated vs never vaccianted dogs that was enlightening; especially since so many dogs are suffering extreme allergies which vets cover up with Prednisone.

[conservative cat]

I never (knowingly) had food allergies as a kid. Now, as an adult, I have figured out I am allergic to tree nuts (not peanuts- thank goodness), soy, watermelon (!!), avocado, and a few other things I suspect (bananas, cucumber, and shellfish) but am in denial so I avoid most of the time and then pop Benadryl when I give in. I also have a slight problem with milk (skin problems) but can handle some dairy. Two of the kids have a dairy problem; one doesn't. I don't know what is going on, but I am not happy. I LIKE food and don't want to avoid it!!

[Riverine]

I've read a theory of some researchers that a child growing up with house pets is beneficial in that it "exercises" the immune system. seems as though there may be a connection to this issue.

[MHT]

I'll have to let my husband know that my "casual housekeeping" had its benefits as my children weren't allergic to peanuts. And thank heaven that they weren't as it was a lunchbox staple with three big boys to feed. In fact, if you forgot your lunch, the school had a jar of peanut butter for last-minute lunches. Furthermore, peanut butter was a standard food item given to you by the welfare department before the days of expanded food stamps benefits.

I'm 52 and don't remember hearing about food allergies until 1983. Then it was milk and red dye, not peanuts. The increase of such allergies is just as alarming as the genetic mutation of the flu. Things just get curiouser and curiouser.

[xroadie]

I never believed in this stuff until I saw my nephew nearly succumb to his peanut allergy. In fact, I think he attended one of the schools in Colorado Springs whose photograph appears in this article.
I am most sad because I cannot imagine a childhood without peanut butter!
I blame TV. I don't know why, I just do.