Mind & Body

The Bite of a Lone Star Tick Can Make You Allergic to Red Meat

There's been a strange, growing threat lurking in the woods for the past few years. You might not see it coming, but when this animal attacks, it could change your life dramatically. The next time you're hiking in the woods east of New Mexico and south of Wisconsin, keep your eyes peeled for the lone star tick — one bite could make you allergic to red meat.

High Steaks Hiking

Picture this: You're out hiking in a national park, and as you emerge from a knee-high patch of tall grass, you spot a little hitchhiker latched on to your calf: a tick, rust red with a tiny white dot in the center of its abdomen. Ick — you brush it off and continue on your way. A couple of weeks go by, and with no sign of Lyme disease, the memory fades. You go out for dinner and enjoy a nice Italian pork sausage, and that night, you wake up sick to your stomach, dizzy and lightheaded, and covered in horrible, itchy hives. That's exactly what happened to Maryland realtor Laura Stirling, and her ordeal isn't likely to be over any time soon.

It sounds surreal, but it's happening more and more frequently. A single bite from this tiny arachnid can cause life-threatening reactions to beef, pork, and lamb. The phenomenon was first noticed by allergist Scott Commins about 10 years ago, and in 2014, he published one of the first scholarly papers on red meat allergies caused by tick bites. When the first cases came in, there were only about a dozen or so people who had suffered the effects. But today, there are more than 5,000 cases in the United States alone. More cases have been observed in Sweden, Germany, and Australia, likely caused by other species of ticks.

Finding the Culprit

It wasn't easy to piece together the cause of the rising red meat allergies. "At first, we thought it was a parasite," Commins told NPR. But when he and his colleagues began to realize that all of the patients were outdoorsy types who had recently been hiking, they began to consider other possible sources of the effect. But how does it happen in the first place? And why is it on the rise?

The answer to the latter question is simple. It's not necessarily a new phenomenon, but it's growing more frequent as the ticks' range spreads and their population increases. Like mosquitos and fleas, ticks are biting more people than ever before, and thus, more people than ever before are experiencing some of the strange side effects that the bites can cause. As far as how a tick bite can cause a red meat allergy, well, the answer to that question is a bit more complicated.

Sugar Bomb

It all comes down to a sugar known as alpha-gal. It's a sugar that forms naturally in the bodies of many mammalian species, including cows, sheep, pigs, and dogs, but not in humans. However, our immune system naturally responds to it by deploying aggressive antibodies even though it isn't necessarily harmful on its own (immune systems have a real when-all-you-have-is-a-hammer problem). The ticks don't create the sugar either, but they can pick it up from other animals they've bitten out in the wild. When the ticks inject their alpha-gal-laden saliva into the bloodstream, our immune systems go into overdrive. The result? Even those who have never really experienced a red meat allergy before can suddenly be stricken by severe symptoms brought on by T-bones.

There is some good news, however. Even if you do contract it, the allergy isn't likely to be permanent. Stick to chicken, seafood, or a vegetarian diet for two or three years and you should be fine. Even better, a protein in the ticks' saliva has been identified as the likely cause of the extreme reaction, opening the door to the possibility of creating a vaccine in the near future. But for now, the best way to cope will be to avoid tick bites to begin with — use bug spray, stay out of tall grass, cover as much skin as possible, and stay away from tick-infested areas.

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Written by Reuben Westmaas September 27, 2018

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