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Lone Star tick bites can cause rare meat allergy in some people

Mary Bowerman
USA TODAY
Female "lone star ticks" are known for the white marking on their back.

With the warm summer months upon us, doctors are seeing more cases of a strange tick-related meat allergy. 

With most food allergies it only takes minutes or even seconds for symptoms like wheezing or hives to develop, but the allergy to mammalian meat caused by a lone star tick bite is different. 
 
“It’s not the classic ‘my throat is closing when I eat peanut butter,’ reaction,” according to Dr. Scott Commins, an associate professor of medicine in the division of rheumatology, allergy & immunology at the Thurston Research Center at the University of North Carolina, Chapel Hill. “These [patients] would get hives and talk about G.I. distress, or needing to go to the restroom, and itching and swelling. Some would have to go to the ER to get treated.” 
 
A type of sugar called alpha-gal, which is present in mammalian meat, triggers the allergic reaction, according to Commins.  He said allergists across the Southeast and beyond have seen an uptick in the allergy, with some seeing one to two patients a week. He said UNC has 537 patients, and he knows of allergists with hundreds of cases from Macon, Ga., up to Southampton, New York. 
 
He said doctors first noticed the strange reaction, which is sometimes called alpha-gal syndrome, a little over a decade ago and were able to slowly piece together that those who developed the meat allergy had one thing in common: Lone star tick bites. 
 
“The question was: what in the world is happening to these patients that they all of a sudden develop an allergy to steak they ate successfully for 40 years?” he said, adding that the patients were in areas with high incidents of rocky mountain fever from the Lone Star Tick.  “We wondered could this be due to tick bites? and we went back and started asking our patients and fortunately almost to a tee all of them said had a history of tick bites.”  
 
As the climate has warmed, ticks have continued to expand their territory, causing disease like Alpha-Gal syndrome to pop up further north than ever before, according to Purvi Parikh, a board certified allergist in New York, who is also with the Allergy & Asthma Network.   

“There’s definitely a rise in general in the summer, when people have more exposure to ticks, but the incidents are rising in more areas,” she said, noting that while the syndrome was first noticed in the southeast, it’s spread. “It’s not just in the South now. I am in New York, and we are seeing more incidents …” 
 
As with any allergy, Alpha-Gal syndrome reactions vary with some experiencing sensitivities that go beyond red meat to actual dairy products, and others who experience hardly any symptoms, Parik said. She notes it’s important for people to seek medical attention if they believe they have an allergic reaction. 

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At this point there are still many unanswered questions about alpha-gal syndrome and how the tick bite causes it, Commins said. The tick-related allergy is so new that no government agency appears to have begun collecting data on it. He notes that while there is no FDA approved treatment, the allergy is not a life sentence, and it typically fades over time, though additional tick bites seem to the bring the response back. 
 
“Part of me feels as though we have just kind of scratched the surfaces of what tick bites can do,” he said. “I don’t have the data for that, but just this hunch that they seem to be able to modulate our immune system in ways we may not understand.”