Tick bite causing meat allergy? (alpha-gal oligosaccharide allergy)

When Emily saw repeated comments online about a tick bite causing allergies to red meat we first assumed it was a mass medical delusion.

Turns out the belief comes from a Vanderbilt University allergy researchers claims and a 2009 WaPo article.

… Scott Commins, an assistant professor of medicine and lead author of the U-Va. study published in the Journal of Allergy and Clinical Immunology, said that in susceptible people such as Newell, a tick bite that causes a significant skin reaction seems to trigger the production of an antibody that binds to a sugar present on meat called alpha-galactosidase, also known as alpha-gal. When a person who has the antibody eats meat, it triggers the release of histamine, which causes the allergic symptoms: hives, itching and, in the worst case, anaphylaxis.

But many questions remain unanswered, said Platts-Mills, whose research is continuing. His lab has collected data on more than 300 patients from across the country and abroad.

"We're sure ticks can do this," he said. "We're not sure they're the only cause." Nor do researchers know why anaphylaxis is so delayed or why only some people develop a problem after tick bites. They do know that the allergic reaction is dose-related: Eating a tiny amount of meat probably won't cause a serious reaction. A large steak will….

The University of Virginia’s Thomas Platts-Mills is pushing the tick theory — though a recent abstract (article is $40) equivocates (emphasis mine) ...

The alpha-gal story: Lessons learned from connecting the dots

Our recent work has identified a novel IgE antibody response to a mammalian oligosaccharide epitope, galactose-alpha-1,3-galactose (alpha-gal). IgE to alpha-gal has been associated with 2 distinct forms of anaphylaxis: (1) immediate-onset anaphylaxis during first exposure to intravenous cetuximab and (2) delayed-onset anaphylaxis 3 to 6 hours after ingestion of mammalian food products (eg, beef and pork). Results of our studies and those of others strongly suggest that tick bites are a cause, if not the only significant cause, of IgE antibody responses to alpha-gal in the southern, eastern, and central United States; Europe; Australia; and parts of Asia. 

So the belief that a tick bite is causing a meat allergy has a basis in at least newspaper reporting and at least one team’s publications.

From my literature search it’s not clear anyone but Plats-Mills and his collaborators are making the strong connection to tick bites, much less to the Lone Star tick. I’d file this one under “suspect”. Of course that means that if Plats-Mills is right about the tick connection he will be well rewarded.

I’d bet he isn’t.