Alpha-gal syndrome cases are growing on the Cape and Islands

Tick season is upon us again and this year is already proving to be a bad one. The Barnstable County newsletter is reporting that tick bites so far this year are nearly triple the usual number.

Most locals worry about getting Lyme disease, but there is a lesser-known tick-borne illness, alpha-gal syndrome, that is a growing cause for worry.

Alpha-gal syndrome (AGS) causes an allergy to all mammalian products, like red meat and gelatin. Some of those with AGS also become allergic to dairy. Even some wines contain bovine gelatin in the fining agents that winemakers use to clarify and remove impurities. Symptoms of alpha-gal include hives, intense itching and severe gastrointestinal issues.

Alpha-gal cases have been especially prevalent on Martha’s Vineyard, but epidemiologists suspect the number is also higher than previously presumed on Cape Cod.

Infection is Now Reportable

But now it will be possible to tell just how many people suffer from it because, as of April 1, 2026, AGS is a reportable condition in Massachusetts. The data is coming in faster than anyone expected.

“We’ve already had five cases here on Cape Cod, so we are in the process of going through them and investigating those cases,” said Stephanie Barth, MPH, communicable disease investigator and health educator for the Visiting Nurse Association of Cape Cod (VNA) Public Health and Wellness Division. “It’s very surprising how quickly these cases are coming through. We suspected that they were here on the Cape before, but now it’s great that we can monitor that and see that it actually is here and what people are experiencing.”

Physicians report cases of alpha-gal syndrome to MAVEN (Massachusetts Virtual Epidemiology Network) when lab results indicate it is present in a patient. Then Barth, who is the disease investigator for 12 of the 15 towns on Cape Cod, investigates whether it is an actual confirmed case or just a suspected case.

“With alpha-gal, you need to have a positive lab (result) and you need to have the symptoms that coincide with consuming or being exposed to red meat,” she said. “So, part of my job in investigating on alpha-gal cases is determining if those people have symptoms as well, because you can have a positive lab and not have symptoms.” In that case, she said, it would not be considered a confirmed alpha-gal case.

‘Double-Delay’ Diagnosis

Part of the reason it takes most people quite a while to get an actual diagnosis is what epidemiologist Lea Hamner, who works at the Martha’s Vineyard Tick Program, calls the “double delay.”

“There is first a delay between the bite and any allergy, and that’s weeks to months, so you’re not going to become allergic tomorrow,” she said. “You’re not going to become allergic next week. And then the next delay is between eating the food and then having the reaction.”

Hamner also called AGS “the midnight allergy” because most people eat their biggest portion of mammalian products at dinner. Symptoms appear two to eight hours later when most people are in bed.

A Personal Experience

That is exactly what happened to Truro resident Priscilla Cornell.

“I had three episodes that were really classic,” she said. “The first one was at the end of January. The second one was in February and the third one was Easter Sunday night.”

The first episode occurred while she was on vacation in Belize. She had a few bites of a hamburger and a big portion of flan.

“Literally six hours after I ate it, I was violently ill,” Cornell said. “When I say violently, I couldn’t get off the bathroom floor. My husband, Chip, put me in the shower and then my feet and hands started to itch and turn bright red.”

Cornell, who is also allergic to clams, peanuts and papaya, recognized that she might be having an allergic reaction, but she didn’t have her epi-pen with her. Her husband gave her Benadryl and she woke up the next morning feeling a little tired but otherwise fine. The second episode occurred after she ate a yogurt for breakfast. By 2 p.m. she was again violently ill with both upper and lower gastric symptoms and bright red hands and feet.

But it wasn’t until the third episode that she and her family members figured it out. She had a few bites of lamb at Easter dinner and she also made an orange cake and she splurged on the whipped cream topping. Six hours later the same symptoms returned. Cornell asked her PCP to order a test, which came back negative, but her PCP urged her to make an appointment with an allergist for further testing because IgE antibodies that indicate alpha-gal can fluctuate.

Cornell has an upcoming appointment at the Allergy and Asthma Centers of Cape Cod for further testing.

“I stay away from all dairy and stay away from all meat and I’m fine,” she said. “The jury is still out, although I suspect when I go see the allergy doctor on Wednesday, they’re probably going to tell me what my PCP told me.”

One of the puzzling things for Cornell is that she has eaten meat and dairy many times between her first and third episodes with no symptoms. Hamner said that is common and one of the frustrating mysteries about alpha-gal syndrome. Since people don’t react after every exposure, they think they’re better and they’re not. Hamner also explained that consuming alcohol with food and exercising after you eat both make the reactions more consistent every time.

Double Avoidance

In addition to the double delay of AGS, Hamner said there is also a need for double avoidance. With double avoidance, you start taking the foods out of your diet that cause a reaction. She recommends working with a nutritionist to make sure you are still eating a healthy diet. But you also must avoid more tick bites because it’s possible, for some people, that the allergy will go away after a few years.

Having AGS gets more complicated because it’s not always easy to know what items contain mammalian products. For example, some medications contain them. Hamner recommends the Pill Clarity website to check your medications. People with AGS also have to get really good at reading labels.

The U.S. Congress is now considering a bill called the Alpha-Gal Federal Inclusion Act that would require food companies to label food that could trigger alpha-gal. Until it passes, Hamner recommends the Food Is Good (FIG) app, which can scan bar codes to let people know if mammalian products are present.

“In the absence of labels, the Food Is Good app has helped a lot of people do their grocery shopping here in a much safer way,” she said.

The Only Prevention

The only way to prevent alpha-gal infection is to avoid being bitten by lone star ticks. Barth, Cornell and Hamner all wear clothing treated with permethrin every time they go outdoors. You can buy permethrin spray at most hardware stores and gardening centers. You must retreat clothing every six washings and footwear every six weeks. Pretreated clothing is also available that is good for between 40 and 70 washings.

“There is only one place where you can send your own clothing in, which is really nice for pants, and that’s called Insect Shield,” Hamner said.

Barth also uses Insect Shield for both herself and her dog.

“I actually sent the cover of my dog’s bed to be treated, so that way when he comes in from the outside and lays on his bed, it will kill off the ticks,” she said. “I’ve seen a huge improvement with that because it’s hard to find ticks on your dog.”

Insect Shield offers a 15 percent discount with the code: capecod2026.