Allergies to red meat caused by tick bites are on the rise: Salt: NPR

Tick ​​bites can cause all kinds of unpleasant afflictions. And if you're bitten by a Lone Star tick, here is another addition to the list: an allergy to red meat.

Laura Stirling, 51, a real estate agent who lives in Severna Park, Md., Was diagnosed with allergy last year. She had a tick bite while walking on a track with her dog, Gunner, near her home.

"I found [the tick] "Stirling remembers, at that time, she said that she did not think much about it." I just removed it and threw it away.

Then, three weeks later, after eating an Italian pork sausage for dinner, she had a horrible reaction. The reaction started about six hours after his meal, which is typical of this allergy.

"It was the middle of the night, I woke up covered with hives," Stirling recalls. She woke her husband with all its itching and scraping. She felt dizzy, and she experienced stomach upset and other gastrointestinal troubles.

An allergist gave her a blood test to check for an allergy to alpha-gal meat. When the test came back positive, he was told to avoid all red meat, including beef, pork and lamb. (Despite a long-running campaign that markets it under the name of "The other white meat," pork is classified as red meat.) Some people who develop allergy can no longer tolerate dairy products .

Stirling was surprised when she heard the news. "I thought it was completely crazy, because I ate dairy and red meat all my life," she says. But she quickly realized that the diagnosis was good. Meat and dairy products have triggered its symptoms.

"His story is really interesting," says Dr. Scott Commins, an allergist and associate professor of medicine at the University of North Carolina at Chapel Hill. He says it's an allergy to meat, but about 15 to 20% of patients with alpha-gal allergy also report dairy symptoms, especially high-fat dairy products such as cream ice.

About 10 years ago, Commins was among the first doctors to identify allergy in patients with tick bites. At the time, there were only a few dozen known cases.

This has increased considerably. "We are confident that the number exceeds 5,000 [cases]"There are also cases in Sweden, Germany and Australia, probably related to other tick species.

In the United States, the Lone Star tick has extended its range beyond the southeast, and there are documented cases of allergies to alpha-gal meat further north, particularly in New York, Ontario. Maine and Minnesota.

"The tick's reach is expanding," says Commins. It's the same for allergy to red meat that it can cause. "We have a blood test, and the word comes out."

Commins began trying to solve the mystery of what caused an allergy to red meat in 2007, when he was at an allergy clinic at the University of Virginia. "We have had a growing population of people reporting these reactions [to meat]He recalls.

At first, ticks were not on his radar. "We thought it was a parasite," says Commins. But then he and his colleagues realized that many patients were outdoor types who spent time hiking. And finally they restored the tick bite connection.

A clue came from the mapping of found cases of allergy to meat. When he compared this with the geographical distribution of Rocky Mountain spotted fever, also caused by the Lone Star tick, he saw striking similarities. "This map overlapped very well with the states where we found these emerging reactions to beef, pork and lamb," he says.

There is still a lot to learn about alpha-gal allergy. Alpha gal is a sugar that animals – including cows, pigs and lambs – make in their bodies. "As humans, we do not make this alpha gal sugar," Commins says. "We all have an immune response to that." So, how does a tick bite cause allergy?

It is possible that ticks inject humans with alpha gal when they bite. Ticks probably get it from feeding on wild animals, such as mice or squirrels, which also carry alpha gal. Or it is possible that the ticks activate the answer in another way.

"All that tick does, it seems like it's a very powerful awakening for our immune system to produce antibodies," comments Commins. "And in this case, they are antibodies against this very particular sugar in red meat."

Laura Stirling now avoids all red meat and dairy products. "As soon as I stopped, I was fine, I felt good," she says.

"I eat enough poultry and seafood in my diet," she says, so she does not want beef. And with all the non-dairy options now available, she says that it's not difficult to avoid milk. "But I have a bit of a lack of having, you know, a bowl of ice cream or a very good cheese."

She looks forward to the day when she can eat foods like prosciutto and salami – and ice cream – again. And there is a good chance that it exceeds allergy.

"He can solve," commented Commins. But he adds a caveat: "We need people to avoid the extra tick bites for the downward allergic response." For people who like to be outdoors, it can be a challenge.

"I'm carrying an insect repellent and I'm very careful," says Stirling.