As Lone Star ticks have spread from the Southwest to the East Coast of the United States, the number of people suffering an allergic reaction after eating red meat has increased, CBS News reported.
However, many doctors and patients are unaware of this growing problem.
"Why would someone think they're allergic to meat when they've been eating it their whole life?" Dr. Erin McGintee told CBS News. She's an allergist who has reportedly seen 200 cases of this type of red meat allergy among people on New York's Long Island.
Lone Star ticks carry a sugar called alpha-gal, which is also found in red meat, but not in people. Normally, alpha-gal in meat poses no problems for people. But when a Lone Star tick bites a person, it transfers alpha-gal into the bloodstream.
As a result, the person's body produces antibodies to fight the sugar. The next time that person eats red meat, their immune system responds to the alpha-gal in the meat and they suffer an allergic reaction that can include itching, burning, hives and even throat swelling, CBS News reported.
In cases of mild allergic reactions, the symptoms can be treated with antihistamines, but severe allergic reactions (anaphylactic shock) require epinephrine. Some people with the red meat allergy carry EpiPens that deliver a shot of epinephrine.
Most allergic reactions to foods occur almost immediately, but red meat allergic reactions can occur up to eight hours after a person eats meat, CBS News reported.
It's not yet known if red meat allergy is permanent. While some people show indications of recovery, others do not.