Meat Allergy Caused by Tick Bites Presents New Challenge

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A new meat allergy that develops after certain tick bites is forcing those afflicted with it to alter their diets, according to Susan Wolver, M.D., assistant professor of internal medicine in the VCU School of Medicine. 

“Current guidance is that (patients) actually avoid mammalian meat altogether – beef, pork, lamb and venison,” Wolver said. “That’s very distasteful for my patient who loves his steak.”

Wolver is the lead author of a recent article in the Journal of General Internal Medicine highlighting case studies of the newly described allergic reaction to meat resulting from lone star tick bites. Wolver’s article targets primary care physicians who might see related cases but who are still unaware of the allergy. 

“Although this reaction had been described in recent allergy literature, nothing had been written in journals read by primary care physicians,” said Wolver. “We wrote the article to bring awareness to providers who might initially see patients like these but may not have heard about this newly discovered entity.” 

She partnered with Lawrence Schwartz, M.D., Ph.D., chair of the Division of Rheumatology, Allergy and Immunology; Diane Sun, M.D., a fellow in the Division of Pediatric Allergy and Immunology at VCU; and Scott Commins, M.D., assistant professor of medicine at the University of Virginia School of Medicine, to write the article after she treated a patient who developed an allergic reaction after eating beef.

The team highlights three patient cases with the condition. The reaction is thought to be caused by antibodies to a carbohydrate (alpha-gal) that are produced in a patient’s blood in response to a tick bite, specifically thought to be the lone star tick. 

This carbohydrate substance is also present in meat. When a sensitized individual eats the meat, a delayed response of hives and anaphylaxis (a severe, life-threatening allergic reaction) can follow.

Anaphylaxis to meat is a new syndrome identified initially in the southeastern United States, where lone star ticks are abundant. Patients may awake in the middle of the night with hives or anaphylaxis, usually three to six hours after ingesting red meat.

“It is also a unique allergy because it is the first food-induced severe allergic reaction due to a carbohydrate rather than a protein,” said Wolver. 

The article, “A Peculiar Case of Anaphylaxis: No More Steak? The Journey to Discovery of a Newly Recognized Allergy to Galactose-a-1, 3-Galactose Found in Mammalian Meat,” explains this connection and discusses the journey of this discovery. The work appears online in the Journal of General Internal Medicine published by Springer.