If your child has had an allergic reaction or anaphylaxis with no identifiable cause, you may now have another avenue to investigate. Le Bonheur allergist Jay Lieberman, MD, recently studied 218 cases of anaphylaxis from 2006 to 2016 to review their causes and compare them with studies of anaphylaxis causes from previous decades. Out of cases with a distinctly identifiable cause, the most common cause for allergic reaction was alpha-gal – a complex sugar found in red meat. While previously an unknown phenomenon, today allergists are able to identify alpha-gal as a cause of anaphylaxis via blood test. If the test is positive, patients are recommended to avoid red meat to see if their symptoms resolve.  

The Tick Bite and Red Meat Allergy Connection

What is even more intriguing is the connection that studies have made between this red meat allergy and tick bites – specifically from the lone star tick, which makes its home in the Mid-South. Detection of the alpha-gal allergic antibody has correlated with those with a history of tick bites. But, Dr. Lieberman says, this is still a rather rare phenomenon. “Not everyone who gets a tick bite will develop the allergic antibody,” he says. “And not everyone with the allergic antibody will actually develop symptoms after eating meat.”

Red Meat Allergy Symptoms

The symptoms associated with red meat allergy are typical of what you might see with another food allergy such as a nut allergy. Patients typically develop any of the following symptoms:

  • Hives
  • Itching
  • Swelling
  • Abdominal pain and cramping
  • Diarrhea
  • Trouble breathing

Unlike typical food allergies, however, alpha-gal allergy symptoms are delayed – sometimes occurring hours after ingestion. This has made it even more difficult to pinpoint and diagnose, which explains why prior to ten years ago red meat allergies went largely undiagnosed.

Key Research Takeaways

In the 2018 review of allergic reactions and their causes, 85 cases (39%) had a definitive cause with the most common being alpha-gal, which accounted for 28 cases (33%). The second leading cause was various food allergies accounting for 24 cases (28%). Even more promising was that the number of cases with no identifiable cause decreased form 59% to 35%. This could largely be accounted for by the number of cases in which alpha-gal was established as the cause.

Although this is a relatively new identifiable cause, those with tick exposure shouldn’t worry about doing anything differently in their lives. “If you are a person who has had a history of anaphylaxis or allergic reactions without an obvious trigger, this may be something to consider,” says Dr. Lieberman. “Especially if you live in an area endemic to the lone star tick such as the Mid-South.”