A lone star tick with its distinctive white
spot on the back. While currently uncommon in our region, the tick appears
to be on the increase.
Posted Friday, November 25, 2016 12:00 A.M.
Marshall Helmberger of the Cook-Orr
REGIONAL-When most of us smell a burger on the grill at a local restaurant, it makes our mouth water. But for Heather Fealy, of Orr, it prompts a totally different reaction.
"I can feel something going wrong right away," she said, describing the symptoms of a serious allergic reaction. "My throat gets tight and it starts to hurt like strep," she said.
Fealy is the apparent victim of an unusual allergy brought on by a tick bite this past spring, near Orr. Fealy said she found the attached tick and didn't think much of it, assuming it was a common wood tick. But she noticed it had a single white mark on its back, which she now recognizes as a distinguishing characteristic of the lone star tick. It isn't a common tick in northern Minnesota, but like many pests, it appears to be expanding its range to the north, and it can have significant consequences for anyone it bites.
For Fealy, who developed her symptoms in June, it's been a life-changing experience, one that has forced her to significantly alter her diet and avoid places where beef, pork, or other red meats are being cooked.
And Fealy is not alone. Dozens of people across northeastern Minnesota are now suffering from this strange allergy to red meat. It's prompted by a reaction to a particular chemical, known as galactose-alpha-1,3-galactose, or "alpha-gal" as most people call it. It's a carbohydrate that is found in the meat of all mammals, except for Old World monkeys and apes, including humans. Research points to the lone star tick as the means by which the alpha-gal chemical is transferred to humans. If a lone star tick feeds on a deer, for example, alpha-gal can enter the tick's system. If that tick later feeds on a human, it can transfer alpha-gal to the person. It appears that the presence of the chemical doesn't noticeably affect everyone, but for those who do react, the symptoms can range from unpleasant to life-threatening.
Fealy said her first reaction showed up as hives on her arm one evening. She assumed she was reacting to tomatoes, to which she had previously shown some sensitivity. She took an antihistamine and went to bed assuming her reaction would have eased by morning. Instead, she woke to find the hives had spread to her arms and legs. She visited the doctor, who prescribed prednisone, a normally effective anti-inflammatory. But the prescription had no effect. The following morning, Fealy found she had hives covering her entire body, even the bottoms of her feet. "My son said my face was all swollen, and then my tongue, mouth, and throat started swelling."
That prompted a rush trip back to the doctor, who got the reaction under control and sent her to an allergist in Duluth, who confirmed the presence of alpha-gal antibodies in her blood. Fealy said she counts herself lucky to have gotten such a prompt diagnosis, since many alpha-gal allergy sufferers can struggle with it for months before understanding what it is that's causing their reactions.
The cause can be tough to determine because the alpha-gal reaction can take three to six hours to show up after a person consumes red meat. That makes it easy to miss, since people normally assume allergic reactions occur more quickly.
"I had never had an issue with meat before, so it was hard to make the connection," said Suzanne Keithley-Myers, who lives near Knife River. Keithley-Myers was bitten by ticks in June while mushroom hunting near Aurora and began developing symptoms a few weeks later. She was recently diagnosed with the same alpha-gal allergy as Fealy.
Keithley-Myers, however, believes she was bitten by black-legged ticks, otherwise known as deer ticks, not a lone star tick, although she said she didn't pay close attention to them as she pulled them off. She said she developed the distinctive bullseye rash associated with deer tick bites and her doctor put her on a round of antibiotics to prevent Lyme disease.
When her symptoms of the alpha-gal allergy started, she initially assumed it was a reaction to the antibiotics. She described severe pain in her gut and outbreaks of hives. She Googled her symptoms and said the alpha-gal reaction popped up right away in the search engine, but she had doubts given that the lone star ticks aren't known to be present in northeastern Minnesota. "It fit the symptoms, but not the geography," she said.
Her doctor-the same one who diagnosed Fealy-eventually confirmed the same alpha-gal antibodies in Keithley-Myers' blood.
Whether she was infected by a lone star tick isn't clear, and she said her doctor now suspects that other types of ticks might be able to transfer the alpha-gal carbohydrate to humans.
While the alpha-gal reaction occurs most frequently in response to the consumption of red meat, like beef, pork, lamb, and venison, about half of alpha-gal sufferers report a similar reaction to dairy products. Keithley-Myers said that's been among the biggest challenges for her, since she also reacts to milk-related products.
Fealy said she's also shown sensitivity to dairy, which has further restricted the foods she can eat. The dietary restrictions can be more difficult than it might first seem, said Fealy, since many processed foods contain meat byproducts. She discovered that when she reacted to eating jello, and later concluded it was the gelatin, derived from the processing of animal hides and bones, that prompted her reaction.
Her condition has forced Fealy to read food labels closely and to learn what additives are derived from animal by-products. Such additives are not uncommon on other processed meat products, such as chicken and fish, which alpha-gal allergy sufferers can normally eat. Fealy said she has also begun to order emu meat, which has a texture similar to other red meats, but is safe for her to eat since it's from a bird, not a mammal.
While the alpha-gal reaction has likely existed for years, medical researchers have only recently begun to understand it. Research began to ramp up about 15 years ago, when clinicians sought to understand why some cancer patients were reacting to a particular drug, known as cetuximab, which contains alpha-gal. Patients in the southeastern U.S., where the lone star tick is abundant, were the most likely to show a reaction to the drug, and those who did were found to have high levels of alpha-gal antibodies in their blood.
Here in Minnesota, officials with the Department of Health acknowledge that the lone star tick is making its way to the state, although they emphasize that the black-legged tick remains the larger threat in the woods, at least for now. "Right now, we're only getting sporadic reports," said Doug Nietzel, supervisor of the vector-borne disease program at the MDH. But that could be because, for now, the alpha-gal allergy is not a reportable condition in Minnesota. At this point, said Nietzel, "we really don't know how prevalent it is."
Nietzel said the lone star ticks are typically limited in Minnesota south of the Twin Cites, although they have been confirmed as far north as Clearwater County, in north central Minnesota. If they're in northeastern Minnesota, Nietzel suspects they're still pretty rare. He notes, however, that black-legged ticks were once rare in northeastern Minnesota, as well, but have now become well-established in the region. If that same trend plays out with the lone star tick, could northern Minnesotans expect a big increase in alpha-gal reactions?
Nietzel said more research needs to be
done before we can know the answer to that. "There is some scientific basis
for a tick connection, but what we're missing is what else may be connected
with this allergy," he said. "We're not sure what other factors there are,"
he said. "I believe there are other ways this could arise."
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