Bites from these northern Minnesota ticks can turn your body against red meat

MINNEAPOLIS - Carl Pedersen kept getting sick, but he couldn't figure out why.

Repeatedly, the Department of Natural Resources fisheries area supervisor who works out of Walker, Minn., would face seemingly random bouts of stomach flu. Sometimes, the queasiness arrived gradually as he drove home from work. And then, four years ago on New Year's Eve, he woke up in the middle of the night to find his entire body covered with hives.

"I said to the wife, ‘I think I probably should go to the emergency room,' " Pedersen said. After a 45-minute car ride, he entered the hospital as he was going into anaphylactic shock. That was just the beginning of a yearlong path to a diagnosis.

He had alpha-gal syndrome, a rare condition that makes patients allergic to red meat, and sometimes to dairy. The allergy is caused by bites from the lone star tick, which is not present in Minnesota. But three years ago, a CDC report found that there was a small hot spot of these cases in northern Minnesota and Wisconsin.

Now, providers and researchers say that the Upper Midwest cases can't all be attributed to tick bites from traveling to the East Coast, South and Texas, where the lone star tick is most prevalent. Other ticks, they now say, can confer the allergy in the forests and brushy countryside of northern Minnesota.

Dr. Alaaddin Kandeel, an allergist with Essentia Health in Duluth, said he once had a patient bring in a tick to show at an appointment. It was a blacklegged tick, also known as a deer tick, one of the most common types in Minnesota.

Before the COVID pandemic, Kandeel said, he had about 80 patients with the allergy; now, after he has warned many other providers in the Essentia network to look out for the condition, it's more than 200. "We put Duluth on the map" for alpha-gal cases, he said.

Difficult diagnoses

It often takes many doctor visits - and sometimes extreme reactions - to pin down a diagnosis of red meat allergy.

Alpha-gal is the shortened name of galactose-alpha-1,3-galactose, a sugar that is present in all mammals other than humans. Researchers theorize both that ticks make the sugar themselves, and that they may first bite another animal like a deer, which introduces the sugar into their saliva, said Dr. Thomas Platts-Mills, an allergist and immunologist at the University of Virginia. Either way, the result is the same: The tick bites a person, and the immune system reacts to the sugar.

Regular skin tests for meat and dairy allergy won't necessarily show the condition, Kandeel said, so patients must take a blood test. It can be hard to connect the symptoms with meat, because they often arrive four or more hours after a meal.

There is no vaccine against the condition, and the only option is to cut out the foods that trigger it. Some patients will lose the allergy over time, if they are not bitten again, Kandeel said.

Mary Gliniany, who lives on a lake near Brainerd, said she had unexplained, itchy rashes on her upper arms for 20 years that no doctor could resolve.

At night, "I would just beg my husband, ‘Could you just please scratch my arms?' " she said.

Then, in the fall of 2023, Gliniany said she entered a monthslong pattern where she would eat dinner, go to bed, wake up at 4 or 5 in the morning and vomit. She lost 30 pounds. She was eating hamburgers, steak and pork chops that were making her sick, but it wasn't until roughly January of 2024 when she got a diagnosis.

Staying away from meat, dairy and animal products in her diet and personal care items has helped her to feel better, she said. She now eats familiar foods that she knows are safe - shrimp cooked in plant-based butter and potato salad from Walmart.

Sometimes, reactions can be triggered by medications, too.

Kandeel said one woman he saw with alpha-gal allergy had previously been treated in a hospital with the blood thinner heparin, and that doctors didn't believe her when she said the medicine had made her feel ill.

"Heparin is derived from animal sources. That could be the reason why she was getting worse," he said.

And one medical treatment was an early clue to the fact that some in the United States react to the alpha-gal sugar. Platts-Mills was one of the researchers who found in 2008 that some patients reacted negatively to the cancer treatment Cetuximab.

The monoclonal antibody contained alpha-gal. Then, researchers had to find out why patients were reacting to the sugar.

"The map of where these cases were occurring, with Cetuximab, looked very much like the map of Rocky Mountain spotted fever. ... That's when we started thinking about ticks," Platts-Mills said.

Public health concerns

Alpha-gal syndrome has gained more attention recently because Platts-Mills and colleagues published the first paper to conclude that a person died from a severe allergic reaction to red meat.

Since the paper was published, Platts-Mills said he has heard from families of two other people who say their loved ones died from an extreme alpha-gal reaction.

While the first death was in New Jersey, a region where the condition is much more common, Kandeel said that state health officials should start educating the public about the possibility of a tickborne red meat allergy in Minnesota and Wisconsin, too.

"This is a public health issue now," he said.

Alpha-gal syndrome is not a reportable disease in Minnesota or Wisconsin, however, so state health officials have little data on the incidence.

"We suspect that some people living in Wisconsin may have developed AGS from a (known or unknown) lone star tick bite in another state ... and that some people living in Wisconsin may have developed AGS through local exposure from one, or perhaps even multiple, deer tick bites," Elizabeth Goodsitt, a spokeswoman for the Wisconsin Department of Health Services, wrote in an email.

Elizabeth Schiffman, an epidemiologist at the Minnesota Department of Health, said that the ticks that cause alpha-gal allergy in Australia are closely related to Minnesota's deer ticks. But the distribution of known cases in the United States points strongly to the lone star tick, she added.

Still, MDH is trying to track some alpha-gal cases by using electronic case reporting, an automatic scanning system for medical results that some hospitals have opted into. The system just started searching for alpha-gal results a month ago, so it will take time for data to be collected, Schiffman said.

"What we're hoping is that over the next year, we'll just be able to get a better sense of how often people are testing positive for it, [and] get more information to really help understand the picture," she said.

MDH's advice to prevent tick bites of all kinds will help prevent alpha-gal syndrome too, Schiffman said: Wear protective clothing, use an approved repellant like permethrin or DEET, and check for ticks after coming inside from areas with long grasses where ticks linger.

Pedersen, who is often outside hunting or working at his job with DNR, said he is now much more careful to treat his clothes with tick repellant and to tuck his pants into his socks.

"I was very lax at tick prevention" before the diagnosis, Pedersen said. Now, with new precautions, "We still go out into the woods, [but] it hasn't been an issue."

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This story was originally published May 21, 2026 at 5:41 AM.