About 450,000 people in the U.S. could be living with alpha-gal syndrome.
An odd new allergy is spreading throughout the U.S. It’s called alpha-gal syndrome, is triggered by a tick bite, and has made thousands of people allergic to red meat. Here’s what you need to know about the condition — and why scientists believe it’s on the rise.
What is alpha-gal syndrome?
Alpha-gal is a sugar that’s found in beef, pork, venison, milk — and tick spit. The substance isn’t usually an issue for most people when they’re eating a burger or downing a plate of ribs. But researchers think that when a tick bites someone, it puts their immune system on high alert. The body then identifies alpha-gal as a potentially dangerous foreign substance and creates antibodies that target the sugar, so the next time that person has a hot dog, they could break out into hives, experience nausea, vomiting, or diarrhea, or see their throat, tongue, or lips swell.
The odd thing is that people don’t usually feel unwell until hours after their meal, says Theresa MacPhail, Ph.D., author of the new book, Allergic. Most allergic reactions to food occur just minutes after exposure, which is why scientists believe many people might not even realize they’re allergic to red meat at all.
It’s recommended that those with alpha-gal change their diet to cut out meat, carry epinephrine, and avoid tick bites.
How long does alpha-gal syndrome last?
There’s no known treatment for alpha-gal syndrome, and it can be a lifelong condition. The allergy does fade in some patients, though, but it’s crucial that they not get re-bitten, Scott Commins, M.D., Ph.D., a University of North Carolina researcher studying the syndrome, told the Associated Press.
“The tick bites are central to this,” he said. “They perpetuate the allergy.”
According to the Mayo Clinic, some with the allergy can eat meat after 1 to 2 years — if they aren’t bitten by a tick again.
How common is alpha-gal syndrome?
According to the Centers for Disease Control, more than 100,000 people in the U.S. have developed the allergy since 2010, a few years after it was first discovered that it could be caused by tick bites. But the agency recently warned that as many as 450,000 people may actually have alpha-gal syndrome, which would make it the 10th most common food allergy.
They say the allergy’s probably undercounted because it’s so new and relatively obscure. In a survey of 1,500 primary care doctors, the CDC found that about half had never heard of the condition, and only 5 percent said they felt confident diagnosing it. And as we mentioned earlier, the reaction is so belated that patients might not even connect it to their steak dinner.
The allergy is most common in the eastern and southern U.S., where a specific variety of tick, called the lone star tick, is found. The pest is the best known for spreading alpha-gal syndrome, but it’s thought that others can too. According to the Associated Press, cases have been reported in Australia, France, Germany, Japan, and other countries where lone stars aren’t present.
Why are rates of alpha-gal rising?
Experts say it’s partly because more doctors are becoming aware of the allergy and are ordering their patients to get tested. But there’s evidence that climate change is to blame too, Dr. MacPhail tells us.
Warmer temps have allowed the parasites to expand their territory and move further north. They’ve now been found as far as Canada, she says. The milder winters also mean that fewer ticks are being killed off, which has caused the population to explode. The heat and pollution has also changed the composition of our forests, providing more cover for critters, which is like a “smorgasbord for ticks,” Dr. MacPhail says.
“It’s a whole lot of things changing, which have led to rising tick populations,” she says. (We spoke to Dr. MacPhail about how climate change has super-charged other allergens too.)
