A tick bite can trigger allergic reactions to meat. Cases are rising in Massachusetts

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Watch out, hunters and nature lovers. There’s a new(ish) parasite in town.

Massachusetts recently joined nearly a dozen other states in mandating that doctors and blood labs report cases of a tick-borne illness known as alpha-gal syndrome.

The rare but dangerous – and sometimes fatal – condition makes people allergic to red meat and occasionally to products made from mammals, like dairy.

The syndrome is caused primarily by tick bites from the lone star tick, and for more than a decade was most common in Arkansas, Kentucky and Virginia, where doctors have long reported cases.

But now, as the lone star ticks’ range grows and the disease spreads, up to 450,000 Americans may be living with the syndrome, according to a Stony Brook University report.

Alpha-gal is a sugar molecule produced naturally in the bodies of many mammals, but not humans. Ticks can ingest it when they feed on other animals, and transmit it through their saliva.

When a tick bite transmits alpha-gal to a person, the body’s immune system can learn to see it as a threat, triggering the allergy. Symptoms can take weeks after the offending tick bite to develop, and range from hives to stomach pain to a life-threatening allergic reaction.

Here & Now’s Robin Young spoke with allergist and immunologist Dr. Tina Merritt as well as Tony Haigh, who is living with alpha-gal, about the syndrome.

Here are some highlights from the conversation, edited for length and clarity:

Was your diagnosis scary? How did you clear up the hives?

Tony Haigh: “Certainly scary. I carry an EpiPen now. I've luckily never needed it, but I make sure I never travel without one and always have one in my truck if needed.

“Stopping red meat and all mammal products is, of course, the first thing that you do. But the first year that I had it was actually quite tough on me. And so, the remedy is just a lot of antihistamines. And now I eat a lot of chicken and eggs and vegetables.”

How conscious are you of avoiding meat?

Haigh: “It is very real. If I go to a restaurant, it's absolutely a concern that there may be cross-contamination. If I have family or friends who are cooking a meal for me, they may think that, you know, they've modified to help me, which I'm very grateful for. But oftentimes that turkey or chicken sausage that they're substituting has a pork or beef casing.”

How does the tick get that [alpha-gal] molecule and then bite a human and deposit it? Does it ever go away?

Dr. Tina Merritt: “There's a group in Mississippi that measured tick saliva, and they found the lone star tick and the blacklegged tick, which is more common on the eastern coast, they both contain alpha-gal in their saliva.

“We think [the allergy] might go into remission if you don't get bitten again. The hard part is if you get bitten again, your immune system develops a good memory, and you may not be able to go into remission.”

Haigh: “A fear of mine is getting bit by another tick that's infected and having my symptoms get worse.”

Cases on Martha’s Vineyard grew from two in 2020 to more than 500 in 2024, according to the Martha’s Vineyard Hospital. Some people there, even tourists, are taking up strict and sometimes permanent vegan diets so they won't get the symptoms.

Merritt: “The hard part is there's a lot of mammal ingredients, and several things that we use just in daily use. So it could be problems with products. If your skin breaks out from your shampoo, is it the mammal ingredients? It could be. If you're taking a medication, if it has a gelatin capsule, or even sometimes pills can have a binder. There's one called magnesium stearate. There's pre-gelatinized starch.

“So, I myself have alpha-gal. I was dizzy for six months before I realized the pill I was taking had magnesium stearate and pre-gelatinized starch.

“I've had it probably since third grade, but we didn't know what it was back then. Stomachaches [were] my main symptom back then.

“In third grade, I was bitten by seed ticks at Girl Scout camp in Louisiana. And then I was calling my parents on hamburger day with stomachaches. I thought I was being punished on Good Friday for eating a hot dog.”

[Editor's note: Seed ticks are recently hatched tick larvae.]

What’s your advice to people scared of contracting alpha-gal?

Merritt: “There are some plant-based insect repellents. There's also DEET and permethrin. There's even different clothing lines that have tick repellent in the clothes. Also, you can treat your own property if you feel like there's a tick potential in your property. If you have pets, you can treat your pets. So, the main thing is just trying to reduce your tick bite exposure.”

Are there people out there who are undiagnosed?

Merritt: “Absolutely. I think a lot of people go undiagnosed, and they go to the gastroenterologist. They go to the dermatologist, and you know, they may not know this is what was the cause of their symptoms. I've had patients that were having symptoms for five years before they found out that they had alpha-gal.”

 Has this changed how you live your life?

Haigh: “I try to not let fear impact my life too much. I still live an outdoor life. I'm not going to stop walking my dogs in the woods. I'm not going to stop mountain biking, but I'm more aware. One thing that I just really am glad about is that this is getting more attention. Probably one of the most impactful things that could happen is having a [mammal-free] food label, something like a gluten-free or a vegan food label would be hugely impactful for people that suffer with this.

“Again, you go to a restaurant and you don't know about cross-contamination, and you don’t know people are using beef tallow in fryolators, so you may think you're doing the right thing and eat a French fry and have a reaction.”