Hello,

Hopefully, you’ve stepped away from the news this summer to enjoy the sunshine. If this involves a walk in the woods or through grassy fields, remember that ticks thrive in summertime. There’s no need to hide inside, but you might want to tuck your pants into your socks, and spritz yourself with bug repellent.

Ticks have become more abundant, largely because of climate change and the way that humans have altered ecosystems by building houses in once-wild spaces. Diseases spread by ticks have become more common, too. Lyme disease has increased more than threefold in the United States since the early 1990s.

A strange tick-borne malady is on the rise, as well. Named alpha-gal syndrome, it causes an allergic reaction to red meat and dairy. Within two to six hours after ingestion, a person might have hives, itching, difficulty breathing, vomiting, diarrhea, or low blood pressure. When severe, these reactions can be fatal. 

During the reaction, doctors say, antihistamines may help. Lots of people with the condition avoid red meat and dairy. Those on medications look out for animal-sourced ingredients, like gelatin and glycerin, and drugs produced in animal cells. 

Alpha-gal syndrome occurs across the United States, with most reports in Southern, Midwestern, and mid-Atlantic states. Although researchers estimate as many as 450,000 U.S. cases, they say true numbers are higher because the condition is underdiagnosed.

Unlike most tick-borne maladies, viruses and bacteria aren’t to blame for alpha-gal syndrome. It begins when a tick injects its straw-like mouthparts into someone’s skin and a type of sugar called alpha-gal (short for galactose-alpha-1, 3-galactose) flows in. Recognizing alpha-gal as a foreign invader, people’s immune systems produce antibodies to fight it. The trouble is that alpha-gal sugars line cells from cows, pigs, lambs, and goats. So when a person later ingests meat — or milk — from those animals, their antibodies respond, causing an allergy attack. 

Such cross-reactions are a common cause of food allergies. Dust mites introduce proteins that cross-react with those in shrimp, crabs, and other crustaceans, making people allergic. Birch pollen carries proteins linked to soybean allergies. Researchers are studying how to get rid of various food allergies by carefully exposing people to the original offenders. For example, one study found that patients given birch pollen extract began to tolerate soy milk.  

There’s no treatment for alpha-gal at the moment, but some people simply grow out of the condition. As a recent dispatch from the Centers for Disease Control and Prevention reported, “Ten months after first symptoms, the patient tolerated a steak dinner and roast beef sandwich.” 

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Until next week,

Amy

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