COLUMBIA — Zachary McFetters has always been a picky eater. One evening in the spring of 2009, when he was 2 1/2, he wouldn’t touch his food.
In exasperation, his mother, Kristin McFetters, decided to make him a smoothie. She added yogurt and strawberries and threw in walnuts for protein. He drank it down as his mom watched in relief. He would get some nutrients tonight, she thought.
What he did next was odd, McFetters recalled. He climbed off his chair and ran around in circles. Then he ran into his bedroom and threw up. He started wheezing, and hives covered his body.
McFetters recognized it was an allergic reaction and gave him some Benadryl. The Benadryl kicked in, and Zachary fell asleep.
McFetters called a medical clinic's night number and took him to the pediatrician's office the next morning.
The pediatrician tested Zachary for 65 allergens. No allergies, the doctor said.
Still, McFetters decided to be cautious, especially with dairy products. Summer passed, and Zachary didn’t have another reaction.
In November, McFetters was getting ready for Thanksgiving. She put out a bowl of walnuts and a set a nutcracker nearby. Zachary asked if he could try one.
McFetters helped him open the shell and gave him the nut. He bit into it and quickly spit it onto his arm. Hives immediately erupted around the nutty saliva on his forearm and lip.
McFetters was startled, yet relieved that she might have found the culprit. Walnuts.
A few days later, a skin test confirmed a severe tree nut allergy. Tree nuts had not been included in the original blood test, and to this day, McFetters is not sure why.
Zachary, now 8, is allergic to all tree nuts — walnuts, almonds, cashews, pine nuts, macadamia nuts, pecans, chestnuts, hazelnuts, pistachios, Brazil nuts and others — but not to peanuts, a member of the legume family. He is also allergic to pineapple, but that allergy is not as severe.
If Zachary eats a tree nut or eats something that has touched a tree nut, he could go into anaphylactic shock, McFetters said. He could even die.
Food allergies on the rise
The Centers for Disease Control and Prevention found that food allergies increased 50 percent from 1997 to 2011 — from 3.4 percent to 5.1 percent — in children ages 17 and younger.
A 2011 study published by the American Academy of Pediatrics found the number could be as high as 8 percent. The academy based its conclusion on a sample of 38,480 children.
Food allergies among children have reached epidemic levels, said Mark Vandewalker, a board certified allergist with Allergy and Asthma Consultants in Columbia.
Erwin Gelfand, a leading allergist and immunologist who leads the department of pediatrics at National Jewish Health in Denver, offers a similar conclusion.
"Is it an epidemic, yes, the numbers are there," Gelfand said. "It’s very general. It’s not restricted to an ethnic population, a geographic area. It is, in quotation marks, of epidemic proportions."
Marcy Markes, a nurse practitioner with Columbia Allergy and Asthma Specialists, said allergies "are increasing about tenfold every decade," but she hesitated to call it an epidemic.
People are more aware of allergies than they were 50 years ago, she said.
"My parents talked about sinus, and that is a signal of an allergy," she said. Back then, people just lived with it.
In Missouri, the seasonal allergy triggers are trees in the spring, grasses in the summer and weeds in the fall, Markes said. The year-round triggers are molds, dust mites and animals, typically a dog or cat.
Rising temperatures, known as the greenhouse effect, have contributed to the rise in pollen count and the corresponding increase in seasonal allergies.
"The pollens are more abundant when they hit," Markes said. "They're hitting faster with more strength and vigor."
On the list of food allergy triggers are the big six, Vandewalker said: milk, eggs, wheat, soy, nuts and seafood.
But someone with a true food allergy is different from a person with an intolerance or an autoimmune disorder like celiac disease, Markes said.
Some people with a gluten intolerance might not have celiac disease but might feel a lot better if they take wheat, rye and barley out of their diet, she said.
Her clinic focuses on patient education. Children with true food allergies are taught from a young age not to take food from anyone except their parents or other trusted adults, she said.
Gelfand also works with patients to help them understand their conditions.
"The biggest concern we have is differentiating between those who are truly allergic and those who think they are allergic," Gelfand said.
A person who is genetically predisposed and has contact with the allergen — whether it's a tree nut protein, cat dander or bees — is more likely to have a true allergy.
Markes said chemicals in foods could also be factors.
"Anything you can do to eliminate the preservatives and stuff, you're going to decrease the inflammatory response," she said.
Schools have had to adjust.
In 2006, the CDC found that 88 percent of U.S. schools had at least one student with a food allergy.
Columbia Public Schools accommodates students with special needs after collaborating with physicians to confirm true allergies, said Lori Osborne, health services coordinator for the district.
"Typically, peanuts or tree nuts cannot be brought in because of safety and health," she said. Some schools in the district even have classrooms that are free of peanuts or tree nuts.
"It is the great mystery of our profession," Vandewalker said. "If someone can find the cause, they would get the Nobel Prize."
The nitty-gritty of an allergy
Food allergies appear without warning, just like other immune responses such as seasonal and medical allergies, eczema, asthma, and even Type I diabetes. What happens to the body during an allergic reaction is understood, but the reason allergies develop in the first place is not.
"While there are some hereditary links, anybody can develop an allergy to anything at any time," said Heather McCain, the allergy charge nurse at ENT and Allergy Center of Missouri.
The difference between a person with allergies and a person without is the way a person's immune system reacts to these seemingly harmless proteins, Gelfand said.
The immune system's primary responsibility is to protect the body from harmful bacteria and viruses, which it does by producing proteins called protective antibodies. Other proteins assist as the body launches an attack on germs.
An allergic person, like Zachary, produces a different kind of antibody, known as an allergic antibody. When his immune system comes into contact with tree nuts, his allergic antibodies respond by binding with the tree nut proteins, triggering the release of histamines and other mediators.
"It's those mediators that are responsible for an acute reaction and ones that can be anaphylactic, which can be life-threatening," Gelfand said.
Anaphylactic symptoms include difficulty breathing, persistent wheezing and fainting, according to the CDC. Other common, but less severe, symptoms include gas, diarrhea, hives and a stuffy nose.
Epinephrine is the treatment of choice for anaphylaxis. It's a form of adrenaline that halts the body's allergic response. An EpiPen delivers injectable epinephrine and is more common these days in schools, public spaces and children's backpacks.
Hospitalizations for anaphylaxis are on the rise. From 1999 to 2009, hospitals experienced a 20 percent jump in anaphylactic patients, according to a 2013 study from the American Academy of Allergy, Asthma and Immunology.
Food is the leading trigger in children and adolescents, according to a 2013 CDC report.
The good news for many families is that, thanks to the effectiveness of epinephrine and to growing national awareness of food allergies, just 0.3 percent of people who were hospitalized in the past decade for anaphylaxis died.
Often, that's fewer than 225 people a year nationwide. But to a family member of an allergic person, it is enough to be terrifying.
Life with allergies
McFetters said life has been an adjustment for her husband, Butch, and two other sons, Brendan, 12, and Kyle, 14.
Zachary’s food allergy affects nearly every decision the family makes. The McFetterses have never flown on a plane as a family. It's too risky to be 30,000 feet in the air and have an allergic reaction. They drive or take Amtrak to Massachusetts to visit relatives.
The family's house on Faulkner Court in northeast Columbia is a tree-nut-free sanctuary. Zachary doesn’t have to worry while he’s there.
The rest of the world can be a menace. On one trip, Kristin McFetters discovered an almond buried in one of the seat cushions on the train. She leaves no space left unchecked before Zachary sits down.
He hasn't yet gone to friends' homes without his mom, his grandmothers don't kiss him hello, and he couldn't play at Stephens Lake Park until he was 6. A grove of walnut trees surrounds the sand where children play, and his parents didn't take him there until he was old enough to recognize a walnut.
Instead of parenting magazines on the coffee table, the McFetterses have copies of "Allergic Living." One of Zachary's role models is Adrian Peterson, a running back for the Minnesota Vikings who developed a severe shellfish allergy in 2012. Peterson is on the cover of the summer 2014 edition.
Other parents of allergic children have questioned her decision to ban tree nuts from her home. They tell her that Zachary should learn how to navigate a world filled with nuts, even at home.
McFetters would rather make it safe for him so he has the energy to venture out into the world. It's exhausting for him to be in unknown surroundings.
Zachary was spent at the end of a trip to the zoo last month. It was a busy day, so he walked most of the way with his arms up in a defensive position, superhero-style, warding off enemies that could be as small as a crumb.
A friend he invited along opened a package of crackers when she got hungry. Zachary stepped away.
Even the holidays offer special challenges. Halloween is especially scary for the McFetterses. Zachary's mom worries about the Almond Joys or Hershey's with almonds landing in her son's candy bag.
She and her husband came up with a solution to allow their sons to participate. They pay Kyle, Brendan and Zachary $10 for each bag of candy. Then the boys eat tree-nut-free cupcakes and chocolate when they get home.
"I think a lot of people think they understand allergies," she said, "but I don't think you really understand until you live it."
The cost of a healthier population
The sharp increase in food allergies in the past few decades makes it unlikely that genetics are to blame, Vandewalker said.
Allergists point to foods that are overly processed with chemicals and additives or the age when an infant is introduced to common food allergens. Other possibilities include a change in the type of oils consumed, a diet lacking in antioxidants, a vitamin D deficiency, and how food is prepared (roasting versus boiling peanuts).
Factors such as obesity, the intestinal health of the mother, in utero exposure, skin exposure and dietary changes also are being investigated.
One of the hypotheses, called the "hygiene hypothesis," is a concept first observed by researchers in the 1980s.
Erika von Mutius, a German pediatric allergist, studied the differences in allergy and asthma rates between East Germany and West Germany just after the Berlin Wall fell. She, along with two other researchers, expected to find higher numbers of allergic children in polluted East Germany, but found just the opposite.
Children in cleaner West Germany had 50 percent more allergies and hay fever than children in the more polluted and less developed areas.
Von Mutius hypothesized that if an environment is too clean, the immune system begins to fight itself.
The result is an underdeveloped immune system that eventually “gets bored,” and it turns on itself, Vandewalker said.
Vandewalker spent a few days visiting East Germany in the early 1980s and saw firsthand how poverty and pollution affected people.
He said that when East Germany caught up to West Germany infrastructure, it also caught up allergy-wise. It took just 10 years for East Germany’s allergy rates to catch up with West Germany’s rates, he said.
Unfortunately, a cleaner environment might have come too quickly for the immune system to have developed an appropriate response.
"Increasing socioeconomic status increases allergies," he said. "But don’t think that’s a bad thing, because it cleans up a lot of other things."
Like the general health of the population.
To wait or not to wait?
Another theory suggests that parents shouldn't wait to introduce risky food to children — contrary to previous advice. Researchers say that delaying allergens into a child's diet might be promoting allergies rather than reducing them.
Earlier oral exposure might reduce the development of allergies since children are exposed routinely anyway, through the air and skin and even in the womb. Researchers believe that minimal exposure might inadvertently create an allergy but that added exposure through diet can help build tolerance.
"When I was a pediatrician 30 years ago, the advice was to wait to introduce the allergen," Vandewalker said.
"Evidence is coming out now that that may be backwards. By avoiding things early in life, we stimulate the body’s immune system to overreact later in life."
Research by Gideon Lack, a British allergist and professor at King's College London, suggests early skin exposure without oral exposure could be contributing to allergies.
A study of British and Israeli children determined that even though Israeli children ate peanuts earlier and more often, they experienced fewer peanut allergies.
Amish children are exposed to everything from hay to raw milk and the cows that produce it, and their allergy rate is one the smallest in a westernized country.
Vandewalker tells expecting mothers and families with infants that the evidence doesn’t really support waiting on food.
"We honestly don’t know, and this is an area that is changing quickly and there is good evidence that you do not harm your child by feeding them early," he said. "In fact, that may turn out be the opposite."
The financial burden
Food Allergy Research and Education, an advocacy group, estimates that food allergies cost the country about $25 billion a year.
Drew and Amy Pope, both 29, are experiencing the financial burden. Their children, Vance, 5, and Nola, 3, both have multiple allergies.
A sticky note with the forbidden list is stuck on the Popes' refrigerator: peanuts, dairy, soy, eggs, fish, beef, pork and wheat.
Vance is less allergic than his sister, but Amy Pope is cautious. She knows allergies can escalate quickly and tries not to provoke their immune systems.
The biggest worry is peanuts for both children. Nola’s allergy, like Zachary’s, is severe.
Pope said she always dreamed of being a stay-at-home mom. When she met her husband at 19, she fell in love and knew that kids weren’t far off. Pictures of her children at every age adorn the walls of the Popes' two-level townhouse in north Columbia.
The past few years have been rough. Their monthly food budget exceeds $700, and Pope realizes that she might have to return to work or go back to school. The expense of feeding two hyper-allergic children is overwhelming. At their age, it’s manageable, but she worries about how much it will cost as they get older.
The two kids can split a $4 container of vegan, gluten-free macaroni and cheese and be full, but, she wonders, what happens when they eat three times that?
“I went from wanting to stay at home to having to stay at home,” Pope said. Their allergies have changed a lot of things, she said.
“I want to get a job so that my kids can do camps and fun things. Those things are too expensive now.”
The future of food allergies
Milk and egg allergies are often outgrown, Vandewalker said. But seafood and nut allergies are more likely to persist into adulthood.
Researchers found that most children outgrow their allergies by the time they're 10, though research suggests that children are growing out of their allergies later than they used to. Children with multiple allergies tend to outgrow them less often and when they're older.
Gelfand and his staff use a technique called the food challenge, pioneered about 40 years ago at National Jewish Health. Under a doctor's supervision, children are given increasing doses of questionable food to determine whether it elicits a severe reaction.
Families come from all over the world to be evaluated, Gelfand said. Parents and children are often fearful about the process, but "we can get 90 percent of kids back on 90 percent of foods," Gelfand said.
"You can turn the family's life around," he said.
McFetters has been told that it's unlikely Zachary will outgrow his allergies. In the meantime, she is equipping him with knowledge and is encouraging him to speak up for himself. He might always have to be cautious with food.
She has many uncertainties about his future. What happens when he starts dating or drinking? Just a moment of recklessness could be devastating, McFetters said.
Zachary is optimistic, though. In his opinion, his allergy has helped the family eat healthier.
"It's great because you get to eat your own homemade food," he said.
Supervising editor is Jeanne Abbott.