Earlier prevalence estimates that have found the range of food allergies as high as 8 percent in children under age 3, but more in the range of 4 percent for older children.

***

Gwen Smith, Allergic Living magazine’s editor, spoke to Dr. Ruchi Gupta, the lead author of the study, about her findings and what they mean. Her study was published  in the journal Pediatrics and funded by the Food Allergy Initiative.

Gwen Smith: In your study you found that 8 percent of children under 18 have food allergies. We’re used to hearing a figure much lower than that for kids over the age of 3 or 4. What do you make of your larger statistic?

Dr. Gupta: It is a large figure, about two kids in every classroom. In practical terms it makes sense, though. I think most parents when they look around their child’s classroom are seeing one or two kids with food allergies, maybe more. I don’t know if it’s a big surprise – since I see it in my own daughter’s classroom and this is true for everyone [parents of patients] that I talk to. I think it’s just getting a good solid number that represents what’s going on in the United States, and that’s what we did.

If you’re wondering if this represents an increase, I don’t really think there’s been a big [recent] one. I know there have been a variety of numbers, there was a report in JACI [Journal of Allergy and Clinical Immunology] of between 1 and 10 percent, so there is a huge range that has been talked about.

GS: But it gets confusing since, while your number is higher, a government agency not long before pegged the prevalence among older children at just under 4 percent.

[Dr. Gupta explains that methodologies are different and that may partly explain. For instance, when the Centers for Disease Control and Prevention came out with the estimate of 3.9 percent of children having a food allergy, they were using a wide-ranging questionnaire on all sorts of diseases, with one food allergy question along the lines of: “does your child have a food allergy or digestive disorder in the past year?”]

Dr. Gupta continues: The CDC report was good, every time we get something we have a little bit more information.

GS: So what was the difference with your study?

Dr. Gupta: What we tried to do was a large, nationally representative study asking only about food allergy. That’s why I feel so confident in what we have produced because it was only for food allergy and we did it on a national level. The number that we have of 8 percent is a very solid number. We took into account families that stated that they may have an allergy to a food and we looked at their reactions. We ended up taking out about 2 1/2 percent of the kids who we thought may actually have intolerances and not allergies. We didn’t just go off a ‘yes, my child has a food allergy’ answer or if we had our results would have been closer to 10½ percent.

We thoroughly reviewed the results with an expert panel to make sure that what we were looking at, based on the history the parents gave us, was true food allergy. The study is carefully done and it looks at all food allergy, not a specific food allergy, so I have a lot of confidence in the numbers.

We did ask, not only ‘does your child have a food allergy,’ but also which allergy and, for each food they reported, we went into: who diagnosed it, how was it diagnosed, what reactions have they [the children] had from ingesting the food in the past. It was a detailed survey that a parent had to fill out.

Next: Serious reactions seen in 39% of allergic kids

A major study in the United States recently found that cases of tree nut allergy in children increased significantly in a decade, from 0.2 per cent in 1997 to 1.1 per cent in 1998. The same study found that more than 3 million Americans now have a peanut or nut allergy.

In Canada, recent research has shown 1.59 % of children have an allergy to tree nuts, and 1 per cent of adults live with the allergy.

In fact, food allergy in general is on the rise in North America and other developed countries. In Canada, an estimated 7.5 per cent of people have food allergies, representing more than 2.5 million people. In the United States it’s estimated that 12 million Americans (or just under 4 per cent of the population) have food allergies.

Here are the rates of some of the major allergens in Canada and the U.S.

CANADA

Source: Surveying Canadians to Assess the Prevalence of Common Food Allergies and Attitudes towards Food Labelling and Risk (SCAAALAR) study. Published in the Journal of Allergy and Clinical Immunology, June 2010.

UNITED STATES

Peanut, Tree Nut or both:
Children -  2.1 %
Adults – 1.3 %

Source: US prevalence of self-reported peanut, tree nut, and sesame allergy: 11-year follow-up. Published in the Journal of Allergy and Clinical Immunology, June 2010.

Peanuts are the most common legume that people will react to, and about 5 per cent of peanut allergic people will react to other legumes, such as beans, peas chickpeas and lentil.

In general, food allergy is on the rise in North America and other developed countries. In Canada, an estimated 7.5 per cent of people have food allergies, representing more than 2.5 million people. In the United States it’s estimated that 12 million Americans (or just under 4 per cent of the population) have food allergies.

A major study in the United States recently found that cases of peanut allergy in children more than tripled in a decade, and that more than 3 million Americans now have a peanut or nut allergy.

Here are the rates of some of the major allergens in Canada and the U.S.

CANADA

Source: Surveying Canadians to Assess the Prevalence of Common Food Allergies and Attitudes towards Food LAbelling and Risk (SCAAALAR) study. Published in the Journal of Allergy and Clinical Immunology, June 2010.

UNITED STATES

Peanut, Tree Nut or both:
Children -  2.1 %
Adults – 1.3 %

Source: US prevalence of self-reported peanut, tree nut, and sesame allergy: 11-year follow-up. Published in the Journal of Allergy and Clinical Immunology, June 2010.

Milk and egg allergy are both common in children. In the United States, 2.5 per cent of children under the age of 3 have a milk allergy. Egg allergy affects 1.5 to 3.2 per cent of children.

The good news is many children outgrow their allergies to milk and egg.

Source: AAAAI

Fish allergy is less common, affecting 0.18 per cent of children and 0.56 per cent of adults.

In general, food allergy is on the rise in North America and other developed countries In Canada, an estimated 7.5 per cent of people have food allergies, representing more than 2.5 million people. In the United States it’s estimated that 12 million Americans (or just under 4 per cent of the population) have food allergies.

A major study in the United States recently found that cases of peanut allergy in children more than tripled in a decade, and that more than 3 million Americans now have a peanut or nut allergy.

Here are the rates of some of the major allergens in Canada and the U.S.

CANADA

Source: Surveying Canadians to Assess the Prevalence of Common Food Allergies and Attitudes towards Food LAbelling and Risk (SCAAALAR) study. Published in the Journal of Allergy and Clinical Immunology, June 2010.

UNITED STATES

Peanut, Tree Nut or both:
Children -  2.1 %
Adults – 1.3 %

Source: US prevalence of self-reported peanut, tree nut, and sesame allergy: 11-year follow-up. Published in the Journal of Allergy and Clinical Immunology, June 2010.

Milk and egg allergy are both common in children. In the United States, 2.5 per cent of children under the age of 3 have a milk allergy. Egg allergy affects 1.5 to 3.2 per cent of children.

The good news is many children outgrow their allergies to milk and egg. Research shows 80 per cent of milk allergy is outgrown by age 16, while 68 % of egg allergy is outgrown by that age.

Source: AAAAI

A major study in the United States recently found that cases of peanut allergy in children more than tripled in a decade, and that more than 3 million Americans now have a peanut or nut allergy.

In Canada, recent research has shown 1.68 per cent of children have peanut allergy. In the United States, 1.4 per cent have peanut allergy. The rates are lower in adults in both countries.

In fact, food allergy in general is on the rise in North America and other developed countries. In Canada, an estimated 7.5 per cent of people have food allergies, representing more than 2.5 million people. In the United States it’s estimated that 12 million Americans (or just under 4 per cent of the population) have food allergies.

Here are the rates of some of the major allergens in Canada and the U.S.

CANADA

Source: Surveying Canadians to Assess the Prevalence of Common Food Allergies and Attitudes towards Food Labelling and Risk (SCAAALAR) study. Published in the Journal of Allergy and Clinical Immunology, June 2010.

UNITED STATES

Peanut, Tree Nut or both:
Children -  2.1 %
Adults – 1.3 %

Source: US prevalence of self-reported peanut, tree nut, and sesame allergy: 11-year follow-up. Published in the Journal of Allergy and Clinical Immunology, June 2010.

Milk and egg allergy are both common in children. In the United States, 2.5 per cent of children under the age of 3 have a milk allergy. Egg allergy affects 1.5 to 3.2 per cent of children.
The good news is many children outgrow their allergies to milk and egg.

Source: AAAAI

OAS is a condition that’s linked to hay fever, which affects a third of the population, so it’s not wonder that so many people are also affected by OAS.

It used to be common for children to outgrow milk and egg allergies before elementary school, two large studies from the Johns Hopkins University show that these allergies are now more persistent and more severe. The studies, published in the November and December 2007 issues of the Journal of Allergy and Clinical Immunology, tracked 800 children with milk allergy and 900 with egg allergy over 13 years.

While previous research indicated most milk-allergic toddlers outgrew milk allergy by the time they were 3 years old, the Johns Hopkins team found that only one-fifth of children outgrew this allergy by age 4, and only 42 per cent outgrew it by age 8. The better news is that a majority was free of dairy allergy by age 16.

With the egg allergy, the trend was similar in the Johns Hopkins’ research. Only 4 per cent outgrew their allergy by 4 years old, and 68 per cent were free of the allergy by age 16.

“The bad news is that the prognosis for a child with a milk or egg allergy appears to be worse than it was 20 years ago,” Dr. Robert Wood, the studies’ lead investigator, told The JHU Gazette in 2008. “Not only do more kids have allergies, but fewer of them outgrow their allergies, and those who do, do so later than before,” said Wood, who is the head of the division of allergy and immunology at Johns Hopkins Children’s Center.

Overall Food Allergy Statistics

In general, food allergy is on the rise in North America and other developed countries. In Canada, an estimated 7.5 per cent of people have food allergies, representing more than 2.5 million people. In the United States it’s estimated that 12 million Americans (or just under 4 per cent of the population) have food allergies.

A major study in the United States recently found that cases of peanut allergy in children more than tripled in a decade, and that more than 3 million Americans now have a peanut or nut allergy.

Here are the rates of some of the major allergens in Canada and the U.S.

CANADA

Source: Surveying Canadians to Assess the Prevalence of Common Food Allergies and Attitudes towards Food Labelling and Risk (SCAAALAR) study. Published in the Journal of Allergy and Clinical Immunology, June 2010.

UNITED STATES

Peanut, Tree Nut or both:
Children -  2.1 %
Adults – 1.3 %

Source: US prevalence of self-reported peanut, tree nut, and sesame allergy: 11-year follow-up. Published in the Journal of Allergy and Clinical Immunology, June 2010.

A major study in the United States recently found that cases of peanut allergy in children more than tripled in a decade (between 1997 and 2008), and that more than 3 million Americans now have a peanut or nut allergy.

Here are the rates of some of the major allergens in Canada and the U.S.

CANADA

Source: Surveying Canadians to Assess the Prevalence of Common Food Allergies and Attitudes towards Food Labelling and Risk (SCAAALAR) study. Published in the Journal of Allergy and Clinical Immunology, June 2010.

UNITED STATES

Peanut, Tree Nut or both:
Children -  2.1 %
Adults – 1.3 %

Source: US prevalence of self-reported peanut, tree nut, and sesame allergy: 11-year follow-up. Published in the Journal of Allergy and Clinical Immunology, June 2010.

The family was waiting on Paige’s appointment with an allergist when 3-year-old Brooke also had a reaction, just days later. “We gave her one peanut, and she immediately dropped to her knees and started vomiting,” Wilson recalls. This was surprising: Brooke had eaten food containing traces of nuts before without incident. Wilson called her doctor back to say, “Now I need a referral for both kids.”

Today at the age of 6, Brooke is allergic to peanuts, and is avoiding all nuts on her allergist’s advice. Paige is allergic to milk, egg, chicken, is avoiding peanuts and tree nuts, and has eczema and several environmental allergies. Michelle and Eldon Wilson always knew their kids could be at risk for food allergies since Eldon is allergic to fish, tree nuts and eggs.

But in that one angst-ridden week, their lives changed forever. After Michelle realized a milk spill “was like a Level 4 biohazard,” the family eliminated allergens from the house. Soy milk became a major source of protein.

Allergists say more and more people like the Wilsons are walking into their offices with longer lists of foods suspected of causing reactions.

“The impression is that there are more people with food allergies, and there are more foods that they’re reactive to,” says Dr. Scott Sicherer, associate professor of pediatrics at the Mount Sinai School of Medicine’s Jaffe Food Allergy Institute. Sicherer, who is the author of Understanding and Managing Your Child’s Food Allergies, also notes that children aren’t outgrowing their food allergies at the same rate they were a few years ago.

In the days before his interview with Allergic Living, Sicherer did a tally of food allergic patients he saw in his New York office. Only three out of 21 were allergic to just one food. Similarly, a 1996 British study of 62 peanut- and tree nut-allergic people found that a quarter of them were allergic to another food, like milk, eggs, sesame or legumes.

But there aren’t many studies yet on the causes of multiple food allergies, as scientists are focused on trying to understand what genetic and environmental factors predispose a person to an individual allergy, like peanut or egg. Sicherer says the population in general is becoming more allergic, including more environmental allergies, eczema and asthma, so more food allergies are just part of that picture.

There is some evidence that multiple food allergies occur in patterns. Some can be explained: for example, someone who is allergic to several types of shellfish.

Other clusters are less obvious. Although peanut is a legume, not a nut, people with tree nut allergies are more likely to have a peanut allergy than the general population, and vice versa. A third of the 5,100 children and adults that the Virginia-based Food Allergy & Anaphylaxis Network has tracked in its tree nut and peanut allergy registry are also allergic to eggs, Sicherer says.

If a baby comes in with milk and egg allergies, “I start to think about peanuts,” Sicherer says. “There’s about a 20 to 25 per cent risk that the child is going to develop a peanut allergy. If that child is not already eating peanuts, I would want to evaluate them for that possibility.”

With the advent of more multiple allergies comes more challenges for allergic people and their families, says Dr. Peter Vadas, director of the division of Allergy and Clinical Immunology at St. Michael’s Hospital in Toronto. Not the least of these can be trying to convince other health professionals how allergic some people are to their grocery list of danger foods.

“I remember patients coming back and telling me their pediatrician was incredulous that the child had so many food allergies,” Vadas says.

Parents, too, can have a hard time grasping a diagnosis of multiple allergies. At first, Karen Eck and her husband Claude Beaucaire of Gatineau, Quebec, didn’t think much about their son Maxime’s troubles with food when he was an infant. Looking back, the boy had warning signs of allergy all along: he threw up frequently, refused to eat some foods, and occasionally got hives.

Eck’s “big wake-up call” was a massive reaction that Maxime had at daycare to green beans just before his second birthday.

Clarke revealed the new prevalence statistics at the Anaphylaxis Canada Spring Conference in Toronto in May. These figures are calculated from the nationwide SCAAALAR survey (which stands for Surveying Canadians to Assess the Prevalence of Common Food Allergies and Attitudes Towards Food Labelling and Risk), on which Clarke is a lead investigator. SCAAALAR is the first formal national tally of food allergies in Canada, with detailed information from 10,000 individuals.

A few days after Clarke’s Toronto speech, the Journal of Allergy and Clinical Immunology published a follow-up study on the prevalence of peanut and nut allergies in the United States.

In their phone survey of 13,500 individuals, Dr. Scott Sicherer and his colleagues at the Mount Sinai School of Medicine in New York determined that peanut and nut allergies in children more than tripled in 2008 from their comparable study in 1997.

In 2008, 1.4 per cent of American kids had peanut allergy and 1.1 per cent had nut allergy compared to 0.4 and 0.2 per cent respectively in 1997. (The combined rate of these two top allergies was 2.1 percent in 2008, compared to 0.6 percent in 1997.)

The SCAAALAR survey, funded by Health Canada and the AllerGen research network, and also published in JACI,  pegged the probable rate for peanut allergy in Canadian kids at 1.7 per cent in 2008, and 1.6 per cent for tree nuts.

Media Muddy Message

These new statistics arrived just as the question is again being raised in the media about how many people truly have food allergies, compared to how many think they have them. An article in The New York Times sparked the debate: it stated that “only” 8 per cent of children have food allergies and 5 per cent of adults have food allergies, then compared that to 30 per cent of the U.S. population who believe they have such allergies.

While these statistics appeared to come from a study published in the Journal of the American Medical Association (JAMA), Allergic Living obtained a copy of the study and those data are not in the report.

What the JAMA report provides is a review of 72 papers on food allergy diagnosis, management and prevention. In comparing available statistics, the medical article does say that more than 1 to 2 per cent, but fewer than 10 per cent of Americans have food allergies.

The report does not address the question of “perceived” versus true allergy at all, and one of the report’s authors told Allergic Living that the 30 per cent figure cited by The New York Times does not apply to the United States.

JAMA’s study was designed to provide guidance to the National Institute of Allergy and Infectious Diseases as its officials develop guidelines to define food allergies and give criteria for diagnosing and managing patients. The authors found that there isn’t a universally accepted definition of food allergy, and that there’s a lack of well-established guidelines for diagnosis.

“The systematic review of the food allergy literature published in JAMA is helpful in crystallizing the fact that food allergy is common, affecting millions of Americans, but also points out that we need much more research to better understand the exact prevalence, and how to prevent, more easily diagnose and treat this life-changing medical problem,” Sicherer noted.

First published in Allergic Living magazine, Summer 2010 edition.
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