Ticks causing mysterious meat allergy

Meat allergies are not very common, according to experts.

Story highlights

  • Alpha-gal: Sugars stuck together in the blood that lead to meat allergy
  • All known patients who have alpha-gal have had at least one tick bite
  • For meat lovers, especially hunters, the simplest solution is to avoid ticks
Helen Olive had her first allergy attack 11 years ago. She had gone to bed only to wake up hours later because her neck felt as if it were on fire.
"It was terrible," said Olive, who is 42 and lives in North Carolina. "The sensation was all over my body and then I developed hives."
A slender woman with wavy, reddish-brown hair and blue eyes, Olive might appear perfectly healthy. But waking up in the middle of the night with uncontrollable itching and nausea became a common theme in her life.
She was driving her motorcycle around town with her husband on a hot summer day in 2008 when they decided to stop for a meal at a local restaurant. "I had a black and blue salad with beef tips," Olive said. "Later I had the same reaction except the Benadryl would not work."
As her symptoms continued to increase, she made an appointment with the Carolina Asthma and Allergy Center. Her blood test showed that she was very allergic to meat. Olive's doctor informed her that a meat allergy was "not common."
But two allergists at the University of Virginia have gathered data showing that the food allergy Olive has, known as galactose-alpha-1,3-galactose, or alpha-gal for short, is affecting more than 1,500 Americans. The researchers suspect there are many more unidentified cases.
"The answer to the allergy is sugar," said Dr. Thomas Platts-Mills, who discovered the allergy with his junior colleague Dr. Scott Commins. They first published their findings in 2009.
Alpha-gal is essentially a bunch of sugars stuck together in the blood, which is in the meat of all non-primate mammals, including deer, cats and dogs. "We have seen anaphylaxis in France with horse and goat meat as well," Platts-Mills said.
What causes the allergy may be surprising.
All known patients who have alpha-gal have had at least one tick bite. Platts-Mills, who also suffers from alpha-gal, made the connection after receiving countless bites while hiking in the woods one August. As a result, his level of IgE, which measures the alpha-gal allergy in one's blood, went up several-hundred points. That is when Platts-Mills concluded there is some relation to the number of tick bites one receives and how allergic one may become to alpha-gal.
Platts-Mills and Commins said the allergic reaction is specifically related to the common lone star tick (Amblyomma americanum). These ticks cover various plains across the United States. An important distinction is that alpha-gal is not a disease like Lyme disease or Rocky Mountain spotted fever -- it is an allergy.
"Presumably something happened with the ticks," said Platts-Mills. "It could possibly be a new tick spreading."
The doctors believe the allergy could more closely be related to bites that come from tick larvae, or baby ticks.
"Perhaps there is an organism in the tick's saliva that makes a person allergic to the alpha-gal sugar in mammalian meat," Commins said.
For meat lovers, especially hunters, the simplest solution is to avoid ticks -- as if that's an easy thing to do.
And what if you've already been bitten? Olive doesn't fancy the idea of eating a steak with an epinephrine auto-injector, which treats life-threatening allergic reactions.
Allergist Dr. Erin McGintee who practices in the Hamptons has seen some dangerous cases of alpha-gal in New York, including a few patients who passed out in their bathrooms.
"Intellectually, it's such a cool allergy on so many levels," McGintee said. "It's a sugar, not a protei