Bad Bite: A Tick Can Make You Allergic to Red Meat

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 only discovered a few years ago but is growing as the ticks spread from the Southwest and the East to more parts of the United States. 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 United States.

Researchers think some other types of ticks also might cause meat allergies; cases have been reported in Australia, France, Germany, Sweden, Spain, Japan and Korea.

Here’s how it happens: The bugs harbor a sugar that humans don’t have, called alpha-gal. The sugar is also is found in red meat — beef, pork, venison, rabbit — and even some dairy products. It’s usually fine when people encounter it through food that gets digested.