The condition is caused by the bite of the lone star tick, which is common across Tennessee and can be encountered not only in deep woods but in yards, parks and other grassy areas. Unlike most food allergies, alpha-gal reactions often don't appear until several hours after eating beef, pork, lamb or sometimes dairy, making the culprit hard to identify.

Symptoms can range from hives, nausea, vomiting and severe abdominal pain to anaphylaxis, a potentially life-threatening reaction.

Dr. Cosby Stone, a Vanderbilt University Medical Center physician and one of the nation's leading alpha-gal researchers, said the condition likely predates its 2009 discovery.

"Really do think that alpha-gal has been with us all along, and we just didn't know what it was, just because we discovered it in 2009," Stone said.

For some patients, the consequences are severe. Aleah Busy, a veteran, farmer and hunter whose life centered on the outdoors, said her reactions have at times made swallowing and speaking nearly impossible.

"I could breathe through my nose, but I couldn't swallow," Busy recalled. "There was times I couldn't talk. I've had anaphylactic shock so bad that I've almost died a couple times."

Busy also described hives that appeared in her joints, including one in a knuckle that she said dislocated her finger for about five days. Her sensitivity became so pronounced that she reported reacting to contact with family members who had eaten mammalian products.

"My family was still eating mammal," she said. "So if they were sweaty and they hugged me, I would have a reaction. If they gave me a kiss on my cheek or my forehead, I would have a reaction."

Medical experts stress that Busy's case is unusually severe and that sensitivity varies widely among patients.

There is some encouraging news. Stone said about half of his patients appear to outgrow the allergy if they avoid further tick bites, while the other half remain affected long-term. Researchers are working to understand whether the condition can be resolved faster or managed with treatment, but there is currently no established cure.

The most effective defense is preventing tick bites: using EPA-registered repellents, wearing protective clothing, checking for ticks after time outdoors and removing attached ticks promptly. People who experience unexplained allergic reactions, especially hours after eating red meat, should ask a health care provider whether alpha-gal syndrome could be the cause. A blood test combined with a review of symptoms and medical history can help doctors diagnose it.

Busy has started a support group for women living with the condition, offering connection to people who have spent months or years wondering why their bodies suddenly seemed to turn against them.

"It was such a steep learning curve," she said. "You learn quick. You have to."

The state's new reporting effort marks a step toward understanding how widespread the condition is, though officials caution that the count likely misses people who remain undiagnosed or who developed the allergy before tracking began.