A red meat allergy brought on by a tick bite is now considered an emerging health concern, and experts warn that hundreds of thousands of Americans could be impacted.
Research released July 27 by the Centers for Disease Control and Prevention (CDC) reports that far more people than previously thought have been affected by this serious allergy, known as alpha-gal syndrome. More than 110,000 suspected cases were identified between 2010 and 2022, but because alpha-gal is likely underdiagnosed, as many as 450,000 people may have been affected since 2010, the researchers report.
“Alpha-gal syndrome is an important emerging public health problem, with potentially severe health impacts that can last a lifetime for some patients,” Ann Carpenter, an epidemiologist with the CDC, said in a news release. “It’s critical for clinicians to be aware of [alpha-gal syndrome] so they can properly evaluate, diagnose and manage their patients, and also educate them on tick-bite prevention to protect patients from developing this allergic condition.”
Alpha-gal’s rise coincides with a spike in other tick-borne diseases, which more than doubled between 2004 and 2016, federal data shows. The alpha-gal allergy can be triggered weeks after a bite from the lone star tick and possibly other varieties.
“We’re continuing to identify new patients every week in allergy clinics across the Southeast and East who’ve had essentially brand-new reactions,” says Scott Commins, M.D., an associate professor of medicine at the University of North Carolina and a leading expert on alpha-gal syndrome. “And that has been a big change over the past, say, 10 years.”
What is alpha-gal?
Symptoms of alpha-gal syndrome
Reactions can range from mild to severe and may include:
- Hives or itchy rash
- Nausea or vomiting
- Heartburn or indigestion
- Cough, shortness of breath or difficulty breathing
- Drop in blood pressure
- Swelling of the lips, throat, tongue or eyelids
- Dizziness or faintness
- Severe stomach pain
Source: Centers for Disease Control and Prevention
Alpha-gal is a sugar molecule — many mammals have it, including cows and pigs, and Commins says researchers have come to understand that some ticks do too. But it’s not found in people, so when a person gets a bite from a tick that has alpha-gal in its saliva, the body creates an immune response to the molecule, and some people have a strong allergic response.
“So then when we eat a hamburger, hotdog, etc., we have an allergic reaction to the meat, and it’s specifically to that alpha-gal that’s in pigs and cows,” Commins says. This is the case even if a person has been able to eat red meat their whole lives without a problem.
Recognizing the symptoms of alpha-gal
Unlike with other food allergies, symptoms of alpha-gal syndrome don’t come on right away. “If you have a peanut allergy and you go out to a restaurant and you get an accidental exposure, you know you’re in trouble before you leave the restaurant,” says Jeffrey Wilson, M.D., an allergist and immunologist and an assistant professor of medicine at the University of Virginia.
With alpha-gal, however, it could be hours — three to six, or more — before hives or a rash develop, or you start to feel light-headed and short of breath. Other common warning signs include indigestion, nausea, vomiting, diarrhea and severe stomach pain.