Photograph by Joel Sartore, National Geographic Photo Ark
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The American Dog tick, while not capable of spreading Alpha-Gal, can be a host to a number of other illnesses.
Photograph by Joel Sartore, National Geographic Photo Ark

A Tick Bite Could Make You Allergic to Meat—and It's Spreading

As people encounter more ticks during the summer months, their chances for getting bitten by the allergy-carrying Lone Star tick increases.

Alpha-Gal may sound empowering, but the nickname, short for galactose-alpha-1, 3-galactose, is a sugar molecule that might just cause you to become allergic to meat.

The sugar molecule is spread from the Lone Star tick bite, named for the Texas-shaped marking on its back. Once bitten by a Lone Star tick, the body's immune system is rewired.

"You're walking through the woods, and that tick has had a meal of cow blood or mammal blood," explained Cosby Stone, an allergy and immunology fellow at Vanderbilt University. "The tick, carrying Alpha-Gal, bites you and activates your allergy immune system."

From this, your body creates Alpha-Gal antibodies and, from that point on, the body is wired to fight Alpha-Gal sugar molecules. The majority of people who develop Alpha-Gal allergy syndrome realize their illness after eating meat, which is rife with Alpha-Gal. The sugar is also present in some medications that use gelatins as stabilizers.

"There's a time delay in the reaction," said Stone, which accounts for why some people don't always immediately realize they're have a reaction. "It [the Alpha-Gal] has to first travel through your gastrointestinal tract to be released. Hours later, patients wake up with hives, shortness of breath, vomiting, and diarrhea."

In rare cases, patients have to be admitted to the ICU.

"Some patients have had to be given life support because their blood pressure is so low that they're in eminent danger of dying," said Stone, who has treated those suffering a reaction.

"Most patients don't know what they have," he explained. It often takes repeated allergic reactions for people to link their diet to their outbreak. Repeated exposure to tick bites can also worsen the severity of a reaction. Those who developed more Alpha-Gal antibodies from more exposure to ticks saw the most serious symptoms.

The allergy so far has treatments for side effects but no cure or vaccine.

Is it On the Rise?

Originally found primarily in the southeastern U.S., the disease may become more common in farther north and western regions that experience warming temperatures. Cases of the tick-borne illness have been popping up as far north as Long Island, New York, and as far west as Minnesota.

The Centers for Disease Control do not log cases of Alpha-Gal allergy syndrome, so most reports of the disease's rise are anecdotal.

"Five years ago, we probably had about 50 or so patients that had Alpha-Gal [syndrome]. Now we have about 200," said Stone. However, until cases were first identified in the past decade, little to none was known about the origin of this meat allergy.

"The awareness of Alpha-Gal has grown," noted Stone. "It's also possible that because allergies in general are going up, reactions to Alpha-Gal are increasing."

Studies have documented that warming temperatures have led to an increase in plant-based allergies from allergens like pollen.

Stone believes advancements in hygiene have led to a weakening of some of the natural immunity we develop to fight allergies.

In an interview with USA Today, Purvi Parikh from the Allergy and Asthma Network warned that as the climate has warmed, ticks have begun to spread their territory farther north.

Regardless, humans come into contact with ticks more frequently during warmer weather, and Stone recommends warding off Alpha-Gal in the same way other tick-borne illnesses are prevented: use insect repellent, pretreat clothes, and avoid high grass and shrubbery.

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