Did you know that meat allergies in humans are on the rise where deer populations are increasing? Locally, after eradication in the early twentieth century, deer in the Blue Ridge Mountain region were re-introduced around 1950.
They became prevalent in the suburbs during the 1980s.
“Subdivisions introduced leash laws,” Thomas A.E. Platts-Mills, PhD, the Oscar Swineford, Jr. Professor of Medicine and head of the Asthma and Allergic Disease Center at the University of Virginia, explains. “It became possible to let your dog out with an invisible fence and it could not escape and chase the deer.”
The deer brought ticks near homes. Dr. Platts-Mills believes about half the people who come into his clinic with a lone star tick bite reaction are bitten on their own property. His lab found that lone star tick saliva may trigger the human immune system to produce antibodies to galactose-alpha-1,3-galactose, a carbohydrate better known as alpha-gal, also found in red meat. This alpha-gal sensitivity causes an allergic response for patients worldwide.
Dr. Platts-Mills’ laboratory discovered that diagnosed cases of alpha-gal sensitivity related to a chemotherapeutic drug, Cetuximab—which also contains the alpha-gal found in lone star ticks—occurred in the same regions (Virginia, North Carolina, Tennessee, Arkansas and southern Missouri) as Rocky Mountain Spotted Fever (RMSF.) Nobody could understand why these reactions were occurring in the same locale. This coincidence caught the notice of Dr. Platt-Mills and his associates.
“We started asking questions and it became obvious that the lone star tick which carries RMSF was the big player in the United States,” Dr. Platts-Mills explains.
Approximately three percent of adults are allergic to alpha-gal. The substance, present in the lone star tick’s gastrointestinal tract, is passed on through its saliva. The alpha-gal diagnosis is now present in South Carolina, Georgia, northern Alabama, and Oklahoma. Recently, 200 cases have been diagnosed in The Hamptons area of New York’s Long Island.
Alpha-gal sensitivity can be difficult to diagnose.
“Pretty much every other food allergy happens right away,” Dr. Ann P. Zilliox, a Newport News, Virginia, allergist and immunologist, explains. For example, “You eat a peanut, I expect in the next 15 to 30 minutes to see anaphylaxis happen.”
However, a delayed reaction time makes it difficult to connect red meat consumption to a particular event, such as a tick bite. Also, a person’s sensitivity varies with the quantity of meat consumed and preparation methods.
“They could eat stew, but not semi-rare steak. They could eat a little meat, but couldn’t eat a 10-ounce hamburger,” Dr. Zilliox explains. “We’re not used to that.”
One of Dr. Zilliox’s patients, Keith Welch, took eight years to connect his allergic reactions to red meat. In 1998, his initial reactions were only hives and mistakenly attributed to medicine and seafood.
“My reactions intensified to include a racing/pounding heart,” Welch explains. “Then they became severe, system-wide anaphylaxis with: dropping blood pressure; racing heart; vision loss; inability to think or speak clearly; loss of motor skills; digestive upset; and extreme panic.”
Welch vaguely suspected meat could be the cause. But, he could not believe he was suddenly allergic to meat.
Charlottesville-area resident, Elizabeth Marotta, was diagnosed over a shorter time period. After camping, she ate pork and started a new medication the same day.
“I woke at 3:00 a.m. with my legs covered in bug bites,” she says.
Elizabeth applied hydrocortisone and took an antihistamine. But the bites spread, creating plaques and swelling on her legs. She
decided it must be an adverse reaction to her new medication. When her face and lips began to swell she went to the hospital where the emergency room physician agreed with her assessment. She stopped taking the medication, but during the summer, she kept getting bit and waking with hives.
That October, she ate steak for dinner and woke at 4:00 a.m. with her throat swelling shut and all-over swelling.
“This time I wasn’t on medication,” Marotta explains.
The emergency room doctor noted the timing of her June visit. When Marotta recounted her steak consumption, he told her she had a meat allergy and needed to see an allergist immediately. She tested positive for allergy to alpha-gal.
“I got EpiPens,” she says of her auto-injector epinephrine. “I was already accustomed to adjusting my diet as I am allergic to corn and soy.”
Marotta completely abstains from eating mammal meat. Her original count of antibodies in the blood that measured at 49 (out of 100) has dropped to about one-and-one-half points over the past two years.
What to Watch Out For
“If around the middle of the night you’re having symptoms of anaphylaxis (waking up short of breath, have hives and gastrointestinal stuff) that happen to track with when you are eating red meat, you may have this alpha-gal sensitivity,” Dr. Martha White, Director of Research at The Institute for Asthma & Allergy in Wheaton, Maryland and a practicing allergist in the Washington, DC area, says. “If you’re eating meat that’s not totally cooked and your mouth is itchy or your lips get swollen or chapped, that’s a clue that maybe you have an allergy to that meat.”
What To Do If You Have an Alpha-gal Allergy
At restaurants, ask your server what stock your soup is based on to avoid contamination. Though everybody with a food allergy cannot eat red meat well-cooked, those who can should ask for well-done meat. And be aware of foods that may contain bacon bits.
“One still has to be careful and carry their auto-injectors,” Dr. White explains.
“Make sure your food wasn’t cooked on the same grill somebody’s steak just got cooked on,” Dr. Zilliox says.
At home use separate serving utensils for meat and vegetables.
What To Do If You Have an Allergic Reaction
“First, take Benadryl,” Dr. Platts-Mills says. “Second, tell someone sensible and have them stay with you. Make sure they know how to use epinephrine.”
Once epinephrine has been administered, call 911.
“I’ve already had a heart attack,” says Dr. Platts-Mills who, incidentally, is allergic to alpha-gal, but only experiences hives. “I don’t want people my age to take epinephrine immediately.”
In most reactions to alpha-gal, the individual feels dizzy, sits down and feels fine.
However, like Welch, some have severe anaphylaxis.
“I’ve been to the emergency room several times,” he says. “I carry an EpiPen and am careful not to eat mammal meat.”
On a positive note, Dr. Zilliox says, “I think certainly everybody in the allergy community in Virginia knows about this now.”
“Trust your body,” Welch says. “If it seems like something’s wrong, then something probably is.”
