Allergic to Life

“We can come up with ways to treat diseases—to make symptoms better or more tolerable—but if we don’t understand fundamentally what’s happening from a biological level, we’re never going to defeat it,’’ says Haynes. “We’ll never understand why more kids are allergic or why a particular drug doesn’t work for everyone. Unless we understand how these cells talk to each other during an allergic reaction, we’re always going to be dealing with it.”

In fact, more of us are dealing with allergies than ever before. The American Academy of Allergy, Asthma & Immunology reports that more than one in two Americans now test positive to one or more allergens, making allergies the fifth most common chronic disease among adults and the third most common in kids. The surge in diagnosed allergies among children—particularly food allergies, which the Centers for Disease Control report have risen by 18 percent in the last decade—has fueled a $3.9 billion market for products aimed at consumers with food allergies and intolerance, and has sparked the creation of “peanut-free zones” in schools and daycares across the country. Whether we’re suffering from a new sensitivity to our environment or what some have termed “an epidemic of diagnosis” is not yet clear, says Malcolm Blumenthal, a professor of medicine and director of the University of Minnesota’s allergy and asthma program. But research like Haynes’ immune-system-on-a-chip could help find the answer.

“Up to now we’ve only been treating the symptoms of allergies, but she’s right where the action is,” says Blumenthal. “Allergies are an adverse immune reaction, and to understand disease you have to get down to the molecular level. Once you understand the pathways involved then you can get very rational treatment.”

“Rational” isn’t the best word to describe how the public has responded to fresh concerns about allergic reactions. Parenting blogs are full of headlines such as “Scrambled eggs almost killed my baby” and “Why won’t my doctor prescribe an Epi-pen?” that can leave the impression that we’re all at risk for a suddenly swollen windpipe. When a Massachusetts school bus was evacuated last year after a stray peanut was found rolling on the floor, one of the parents, a Harvard professor, wrote an article in the British Medical Journal titled “This allergies hysteria is just nuts,” in which he argued that sports participation is a greater risk to children than severe food allergies, yet no one would stand for football-free zones.

Even the new first family has added to the confusion about allergies in its much-debated search for a “hypoallergenic” dog—a creature that may be as mythical as the unicorn. “I suppose anything is possible,” says Blumenthal. “But the clinical wisdom is that the common allergen in all dogs is dander, and most people aren’t allergic to the hair. So the party line is if you’re allergic to one dog, you’re probably allergic to all dogs.”

While some critics have assailed food allergies as the latest form of yuppie hysteria, allergies to nuts, shellfish, and other foods are more than mere nuisance—in the United States an estimated 150 people die each year from serious allergic food reactions, while 2,000 are hospitalized. Even allergic rhinitis, the medical term for run-of-the-mill runny noses and watery eyes, takes a toll in the form of “presenteeism” (not sick enough to stay home, not well enough to get anything done), sapping $700 million every year in lost productivity, not to mention the nearly $6 billion sufferers spend on treatment.

Allergy rates have been rising steadily in the industrialized world, and theories as to why have been on the rise as well. Some scientists suggest allergies are linked to lack of sunlight and low levels of vitamin D, since those of us in northern climates have higher rates of life-threatening allergic reactions. Others say differences in food manufacturing may be a factor—Americans typically eat roasted peanuts, while Asian cultures, which have lower rates of peanut allergies, generally boil theirs. Others question the wisdom of delaying the introduction of certain allergenic foods to children, suggesting that an earlier dose might stimulate a better immune response. (One study of Jewish children found higher rates of peanut allergies among those who lived in the United Kingdom, compared to those who lived in Israel, where peanuts are introduced into the diet earlier.) Researchers in England are even infecting asthma sufferers (some 70 percent of asthmatics have allergies as well) with hookworms, a parasite that’s been missing from most of the developed world, to find out whether they once had a role in rebalancing the human immune system—and as a possible treatment path for such autoimmune diseases as diabetes and multiple sclerosis, which are also on the rise.

Yet another popular theory (often repeated by those of us whose housekeeping skills aren’t what they should be) suggests the cleanliness of our modern environment has lowered our natural resistance to allergens our ancestors may have encountered without incident—a sort of use-it-or-lose-it model of the human immune system. This so-called “hygiene hypothesis” has been used to explain why allergy rates rose after the fall of the Berlin Wall and the westernized clean-up that followed, and why larger families—whose members are, presumably, exposed to more germs than small ones—have lower rates of hay fever and eczema. Yet, as the years go by, the hygiene hypothesis hasn’t explained why asthma rates in the inner city are higher than in the newer and presumably cleaner suburbs. “I think the explanation is much more complex than hygiene,” says Blumenthal. “And it’s not genetic either. We’re talking about a change that’s taken place in the last 50 years.”

Haynes has her own hunches. “I think it has to be something in the environment. It has to be something we’re doing,” she says. “It will be interesting to see the data.”