Tick-related meat allergies are on the rise — yet most doctors don’t recognize the symptoms

They wait for prey in low-lying shrubs before latching on to a viable, warm-blooded host. These parasitic creatures we call ticks can take days to finish feeding, secreting anesthetic chemicals that prevent the host from noticing its iron-gripped bite. All this slurping our fluids makes the tick a prime candidate to spread pathogenic viruses and bacteria. Unfortunately, playing host to ticks makes it easy to contract a variety of diseases.

Lyme disease is the most common form of tick-borne illness and is on the rise, with one study estimating 14 percent of the global population has had it and other data suggesting its incidence has doubled in the past 30 years. But data from the Centers for Disease Control and Prevention (CDC) published last week suggests a relatively new mysterious disease called alpha-gal syndrome (AGS) is also on the rise — and your doctor might not know how to treat or diagnose it. 

AGS triggers an allergy to the alpha-gal sugar molecule found in red meat, dairy, cosmetics, medicines and other mammal products. In some cases, this “meat allergy” can be life-threatening. The report found 110,000 cases of have likely occurred between 2010 and 2022. But because AGS is so poorly understood, it’s likely that number is vastly underestimated. Forty-two percent of healthcare providers responding to a CDC survey published last week reported not knowing what it was and another 35 percent said they were unsure how to handle it.

Estimates suggest up to 450,000 people in the U.S. may actually have been infected with AGS since 2010, said study author Ann Carpenter, of the CDC’s Epidemic Intelligence Service. The illness was only discovered in 2008.

“There are still many questions about alpha-gal syndrome,” Carpenter told Salon in an email. “The specific mechanism by which the allergic condition develops, the association between alpha-gal syndrome and bites from other tick species, why reactions are inconsistent between and among people and how long the condition lasts are just a few of the topics where research is ongoing.”

You may have AGS and not even know it. Symptoms can be mild or severe and range from hives, nausea, heartburn or swelling of the face. Others include diarrhea, coughing or shortness of breath, dizziness and stomach pain. Reactions are also typically delayed, starting at least two hours after exposure, so it might be difficult to tell what is causing them.

AGS is thought to be spread by the lone star tick (Amblyomma americanum), although the possibility it could be spread by other tick types hasn’t been ruled out. The leading theory on how this allergy develops is the tick secretes alpha-gal sugars with its bite, to which the body reacts by sending antibodies to combat the sugar. But once the threat of the sugar is gone, and the tick has left or been removed, the immune response continues to fire whenever the body interacts with alpha-gal again — like when eating a steak. This allergic reaction to these sugars found in red meats and dairy can be debilitating or even fatal.

AGS can be diagnosed with a simple blood test, but there is currently no cure or treatment besides avoiding products with alpha-gal sugars in them. These red meat and dairy allergies can last for years or even a lifetime once they develop, Carpenter said.

---

Want more health and science stories in your inbox? Subscribe to Salon’s weekly newsletter The Vulgar Scientist.

---

Because AGS is thought to be transmitted by the lone star tick, it is of most concern in the southern and southeastern U.S. states, as well as the Mid-Atlantic region. However, tick populations are extending their habitat range as a consequence of climate change. As global temperatures rise, spring and summer seasons in which ticks become active and reproduce are also becoming longer — meaning more ticks and more potential disease, said Richard Ostfeld, of the Cary Institute of Ecosystem Studies.

Lone star tick habitats are already expanding, along with that of the deer tick (Ixodes scapularis), which spreads Lyme disease and another illness called Babesiosis. In the CDC study, the number of AGS cases also rose by 41 percent between 2017 and 2021.

“There are things humans do to the environment that exacerbate the threat of tick-borne illness, including climate change, habitat disruption and biodiversity loss,” Ostfeld told Salon in a phone interview. “Given the strong links of those anthropogenic environmental changes to tick-borne disease, we might expect that in general, these diseases will get worse.”

There are things you can do to reduce your risk of AGS and other tick-borne diseases, primarily by avoiding ticks in the first place. That includes learning about what types of ticks are in your region and when they are active, said Felicia Keesing, of Bard College, who conducted a study examining possible interventions to prevent tick diseases called The Tick Project.

When going hiking or anywhere where ticks might be present, reduce the amount of exposed skin by as much as possible by wearing long-sleeved clothing. Opt for lighter clothing as well, so you can see any ticks that might have tried to latch on. When you get home, check your skin for ticks. For safe measure, toss your clothes in the dryer after any potential exposures, which will kill lingering critters, Keesing said.

In her study, various methods to prevent tick-borne illness successfully reduced the number of ticks in an area, but none managed to decrease the number of tick-borne diseases, she said.

“There are products that have been shown to reduce the abundance of ticks in various habitats, but none of those have been successfully linked to reducing people’s actual cases of tick-borne disease,” Keesing told Salon in a phone interview. “We need to really rethink whether and how reducing ticks in an area connects to tick-borne disease.”