Alpha-Gal: What You Need to Know About the Red Meat Allergy Caused by Ticks

This delay can make it difficult for people to see the connection between what they ate and their symptoms, Commins says. To complicate matters even more, some people experience only gastrointestinal (GI) symptoms, which are easy to blame on food poisoning or a stomach bug.

The American Gastroenterological Association recently updated its guidance for physicians to consider alpha-gal syndrome in patients with “unexplained GI symptoms of abdominal pain, diarrhea, nausea and vomiting” — especially if they live in an area where ticks and the allergy are prevalent (the Southeast, mid-Atlantic, Midwest and East Central regions). The group notes that a history of waking up at night with GI distress may also signal the syndrome.

Another possible warning sign is redness or irritation in the spot where the tick latched on that is slow to heal. “Some folks would say it even felt like a knot under the skin,” Commins says.

If you notice these symptoms after eating mammalian meat (beef, pork, lamb, venison, etc.), talk to your primary care provider or an allergist. A blood test, alongside an exam and patient history, is often used to diagnose the allergy; your doctor may also order an allergy skin test.

One thing to note: If you’re getting a routine allergy test but don’t have symptoms of alpha-gal syndrome, know that some people produce antibodies for the molecule but don’t have a full-blown allergy. “So a positive test does not automatically mean you have a red meat allergy,” Wilson says.

There is no treatment for alpha-gal syndrome, though experts say it’s possible the allergy fades over time, especially if you’re able to dodge additional tick bites. Those with the allergy — which can range from minor to severe — have to avoid red meat and often other products containing alpha-gal, like meat broth or stock and gelatin made from beef or pork. Some people are unable to eat dairy.  

Ticks on the move

Pinning down a reason for the rise in alpha-gal syndrome is tricky, experts say. Food allergies, in general, are increasing, Wilson notes. There’s also more recognition and awareness of alpha-gal, though many health care providers still aren’t familiar with it, the latest CDC research shows.

And because tick-borne diseases are increasing overall, Commins says, “it kind of makes an argument that people are just coming in contact [with ticks] and being bitten more frequently.”

Interestingly, the tick population fluctuates on a yearly basis, says entomologist Michael Raupp. But one thing that has grown steadily is their reach. With warmer temperatures, ticks have been expanding farther north.

“This is a phenomenon that’s going on with lots and lots of different kinds of insects and arthropods, including ticks,” says Raupp, professor emeritus at the University of Maryland. “And because the tick is now moving into these areas, you’re going to have cases of the red meat allergy and [other tick-borne diseases] in these areas where they haven’t been before.”

To avoid ticks and any allergies or ailments they transmit, Raupp has a few tips.

• Stick to a paved surface or the center of the trail when walking or hiking. Ticks are most often lurking in the lush vegetation.
• Tuck your pant legs into your socks if you’re going to be out in grasses and brush.
• Too hot for pants? Reach for a spray repellent. The CDC recommends using an EPA-registered insect repellent containing DEET, picaridin, IR3535, oil of lemon eucalyptus (OLE), para-Menthane-diol (PMD) or 2-Undecanone.
• You can also treat your clothing and boots — not your skin — with products containing 0.5 percent permethrin. The CDC has more information on how to do that. Or you can buy clothing that has already been treated.
• Put your garments directly in the wash or even just the dryer when you get home. “And if you spin that on a medium to high cycle for about 30 minutes, you’ll kill any ticks that might have come home with you,” Raupp says. Also, take your shoes off outside so you don’t bring any ticks in the house, and examine pets and any gear outside as well, such as backpacks.

If you notice a tick on your body — and it’s important to check routinely — make sure you:

• Remove it as soon as possible. It takes the tick about 36 to 48 hours to transmit diseases like Lyme, according to the CDC. “So if you can get that tick off in the first 24 hours, it’s going to greatly decrease your chances of contracting a tick-borne illness,” Raupp says.
• When you do get the tick off, don’t flush it. Identifying the tick can help you understand your risks. “If it’s a black-legged tick, that puts Lyme disease in the picture,” Raupp says. The primary tick associated with a red meat allergy is the lone star tick. Many universities and health departments offer tick identification services, including the University of Maryland and the University of Rhode Island.

Editor's note: This story, originally published May 5, 2023, has been updated to reflect new information.