Q&A: Dr. Erin McGintee Addresses Alpha-Gal Allergy


As if Lyme disease, babesiosis and ehrlichiosis weren’t bad enough, now we have to worry about something called alpha gal-allergy? What’s that?

Alpha-gal allergy is the nickname for the allergy to galactose-alpha-1,3-galactose. Alpha-gal is a blood group carbohydrate that is expressed throughout the cells of all non-primate mammals. Allergy to alpha-gal can develop when a person is bitten by a Lone Star tick, either in adult, nymph, or even larval form. If a person develops alpha-gal allergy, they may experience symptoms of an allergic reaction after eating meat. Unlike most other food allergies, alpha-gal allergy reactions are consistently delayed by 3 to 6 hours. A person with alpha-gal allergy may eat a steak at 6 p.m. for dinner without issue, only to wake up at around midnight in the midst of an allergic reaction. Most reactions include skin itching and hives, and many patients also report abdominal symptoms, including cramping, vomiting, and diarrhea. Some patients may experience shortness of breath or wheezing, and some complain of dizziness or lightheadedness. In severe reactions, patients may experience anaphylactic shock, which is a severe, multi-system allergic reaction that can result in death.

If I get the alpha-gal allergy, do I have to give up all red meat, including beef, pork, and lamb? What about poultry — chicken liver, for instance?

If a person develops alpha-gal allergy, I advise that strict avoidance of all mammalian meat is safest.  There is no need to avoid any part of the chicken, or any poultry for that matter, since poultry does not express the alpha-gal allergen.

Is there a cure for alpha-gal?

As with all food allergies, there is no “cure” for alpha-gal allergy, though we do know that most patients will lose the allergy over time, provided they do not sustain further Lone Star tick bites…. There really isn’t a timeframe. It varies from person to person. I have seen patients lose sensitivity within three months, and for others, the level never seems to go down, even after years. The added complication is that sometimes people sustain Lone Star tick bites, especially from the larva or nymphs, and do not know it.

A decade ago, you hardly ever heard of the Lone Star tick. Now they are everywhere? Do scientists know why they have become so widespread?

It is my understanding that the lone star tick was introduced to our region via birds. Some believe migratory birds brought the tick to Long Island, while others believe that when wild turkeys were introduced to our area, the lone star ticks came along as a parasite. The Lone Star tick is a very aggressive species of tick, and it does appear to be out-competing the other ticks in our area.

I was bitten by a lone star tick.  Should I ask my doctor to test me for this allergy?

This is a tough question, but my answer would actually be no. I do not recommend routine testing for alpha-gal allergy because it is extremely common for patients to have a positive test to alpha-gal without any clinical symptoms…. My recommendation for patients who are concerned about eating meat after a lone star tick bite is to just avoid or limit mammalian meat for a few weeks, which is the period of time when a person is most likely to be reactive, and then gradually reintroduce, starting with leaner meats and advancing back to a full diet.

What about chiggers?

It is a misconception that the itchy bites that many East Enders experience in the late summer and early fall are due to chiggers. There has never been a chigger identified on Long Island. Some people like to argue about this more than they argue about politics, but it is important to understand that those bites are actually due to lone star tick larvae. While we are not aware of lone star tick larvae transmitting any diseases, they can cause alpha-gal allergy, and in fact, they seem to be potent triggers of the allergy.