Lone Star tick bites cause red meat allergy in growing problem

A bug can turn you into a vegetarian, or at least make you swear off red meat. Doctors across the nation are seeing a surge of sudden meat allergies in people bitten by a certain kind of tick.

This bizarre problem was discovered only a few years ago but is growing as the ticks spread from the Southwest and the East to other parts of the U.S. In some cases, eating a burger or a steak has landed people in the hospital with severe allergic reactions.

Few patients seem aware of the risk, and even doctors are slow to recognize it. As one allergist who has seen 200 cases on New York's Long Island said, “Why would someone think they're allergic to meat when they've been eating it their whole life?”

The culprit is the Lone Star tick, named for Texas, a state famous for meaty barbecues. The tick is now found throughout the South and the eastern half of the U.S.

The bugs harbor a sugar that humans don't have called alpha-gal. The sugar is also found in red meat and even some dairy products. It's usually fine when people encounter it through food.

But a tick bite triggers an immune-system response, and in that high-alert state, the body perceives the sugar the tick transmitted to the victim's bloodstream and skin as a foreign substance and makes antibodies to fight it. That sets the stage for an allergic reaction the next time the person eats red meat.

It happened in 2013 to Louise Danzig, 63, a retired nurse from Long Island. Hours after eating a burger, “I woke up with very swollen hands that were on fire with itching,” she said. By the time she made a phone call for help, “I was losing my ability to speak and my airway was closing.” She had had recent tick bites, and a blood test confirmed the meat allergy.

At the University of Virginia in Charlottesville, “I see two to three new cases every week,” said Dr. Scott Commins, who co-wrote the first paper tying the tick to the illness in 2011.