In 2015, Kerry Armbruster of Williamsburg, Va., said she received “the best Christmas present ever.” A diagnosis—with the Alpha-gal allergy, also known as Mammalian Meat Allergy, which is commonly referred to as the red meat allergy.
“I knew that I wasn’t dying of cancer, or Parkinson’s disease,” said Armbruster, who teaches kindergarten.
That was a relief, because Armbruster’s symptoms—difficulty walking, and swelling in her head, hands and feet—potentially pointed to those conditions.
She’d also broken out in hives and had several visits to the ER. She’d been seen by three specialists, and missed 20 days of school between Halloween and Christmas.
“In hindsight [those symptoms] were a godsend,” she said. “There are people who have it and don’t know it.”
Not that the Alpha-gal allergy isn’t a serious condition.
“It’s a life-changing thing, like being diabetic,” Armbruster said.
Now a self-described “medical vegan,” she avoids all contact with Mammalian products.
More deer equals more ticks
The Alpha-gal allergy is not currently tracked by the North Carolina Division of Public Health. But, in the neighboring state or Virginia, there has been a marked increase. Especially in the area of Williamsburg, in the southern portion of the state.
Red meat allergies are on the rise in Williamsburg in particular, said Dr. Ann Zilliox, an allergist and immunologist in Newport News because of its significant white-tailed deer population—the main host of the lone-star tick that transfers the Alpha-gal molecule from deer to humans.
Armbruster doesn’t recall the tick bite that gave her the allergy. It could have been any number of tick bites. Like many people in Williamsburg, she lives in a wooded neighborhood—First Colony on the James River.
“We do a lot of walking and biking, and we are surrounded by trees and deer. We can have eight deer in any one day,” she said.
Her neighborhood, like others in Williamsburg, is a safe haven for deer because hunting isn’t allowed, and there aren’t other predators like mountain lions and bears, said Matthias Leu, a biology professor at William and Mary, who is working on the school’s “Tick Project.”
Leu is specifically looking at changes in the tick population in the Virginia Peninsula–and how various environmental factors may influence the prevalence of tick-borne diseases.
“For ticks, it’s not a clear-cut story,” Leu said. However, one thing is clear: “If you have fewer hosts, you have fewer ticks.”
“The deer population has skyrocketed, and you can follow that line with alpha gal [allergy],” Zilliox said, adding that’s true for much of the Mid-Atlantic region.
And ticks are drawn to the deer because of their size, added Brent Kaup, a professor of environmental sociology at William and Mary who also works on the tick project.
“The deer are large mammals, and because of that, when they tromp through the woods, they are more likely to pick up ticks because of their size,” Kaup said.
Deers, like all non-primate animals, have the Alpha-gal carbohydrate to which some humans are allergic.
“It’s like any other allergy,” Zilliox explained. “There can be a lot of people exposed to cats, and only one person will have an immune response.
“It’s a little bit of an immunological crapshoot,” Zilliox continued. “Certainly, the more you are bit, the greater your risk.”
A food allergy that breaks the rules
Like Armbruster, Ann Mease lives in a wooded neighborhood in Williamsburg, Va. Mease does a lot of yard work, and once, late at night in the spring of 2012, her hands swelled, and she broke out in hives.
She popped a Benadryl, but the swelling increased, so she went to the ER. By the time she got there, her symptoms were less severe, so she went home.
The next morning, she was telling a group of friends what had happened. One of her friends, who had been diagnosed with the meat allergy, asked Mease if she’d eaten any meat that night; and if she’d recently been bitten by a tick.
Mease’s answer to both questions was yes: She’d eaten a hamburger for dinner, and she recalled having a tick on her earlier that week. Mease then followed up with her allergist, Zilliox, and Mease’s blood work came back positive for Alpha-gal.
“There are many unanswered questions about this [allergy],” Zilliox said. “It takes everything that we thought was a hard and fast rule about food allergies and turns it on its head.”
Namely, she adds: it’s a carbohydrate (most food allergies are related to proteins); it’s related to a tick bite, and the allergic reaction is not immediate.
Allergic reactions occur three to six hours after contact with Mammalian products because of the longer digestion process for meat, Mease said.
That delay can be a blessing, Zilliox added, recalling one of her patients on a trip to Chicago who had forgotten his EpiPen. When he realized that he’d eaten something with meat in it, he was able to call Zilliox and have her call in a prescription for another EpiPen to the nearest pharmacy.
“If that was peanuts or shellfish, it would have been over in two minutes,” she said. “In allergies, we assume we have no time at all to plan for things.”
As with all food allergies, there are no shots, so all her Zilliox’s patients carry EpiPen with them. The severity of peoples’ reactions also varies greatly—which a blood test can measure—and can change over time, generally becoming less severe, she added.
“It’s unclear what the natural progression of the allergy is,” she said. “Some people can start eating meat again, but the party line is one you’ve been tested positive for Alpha-gal, avoid meat 100 percent.”
Another unusual thing about the allergy is that it was initially discovered, not in meat per se, but in a chemotherapy drug (cetuximab) with trace amounts of animal product, Zilliox explained. Patients were having anaphylactic shock after taking the drug.
It was researchers at the University of Virginia connected the dots in the early 2000s, by mapping out the geographical areas of the patients who were reactive with maps of lone star ticks, she added.
The best prevention: don’t get bit
That finding in turn led to the identification of the Alpha-gal molecule as the culprit—which has subsequently meant that more and more people are getting properly diagnosed with what was once a mystery condition, Zilliox said.
“We have seen people with this problem for probably 20 years or longer,” Zilliox said. “We’ve finally sort of caught up,” to the back-log of patients. In the past decade, she’s treated about sixty patients with the allergy.
“People who work outside all the time are at greatest risk,” she said. “It’s really hard for them to dress like winter in summer.”
But everyone should in any case, try to prevent tick bites by covering up, wearing a repellent, and tucking pants into socks, she added.
If there’s a silver lining that both Mease and Armbruster agree on, it’s that they eat a healthier diet now.
“It’s made me a healthy person because I’ve really learned about food, which is a good thing,” Armbruster said.
