Tick-Induced Meat Allergy
Scott Commins, MD, PhD, from the University of North Carolina, discussed the emergence of a tick-related meat allergy triggered by sensitization to lone star tick bites.
According to Dr. Commins, people who have been bitten by Ambylomma americanum
ticks may occasionally develop an allergic reaction to galactose-alpha-1,3-galactose—a carbohydrate also known as alpha-gal—after eating red meat. Scientists currently believe the ticks acquire alpha-gal after biting a deer, he said. When the tick bites a person, it injects alpha-gal into the person in its saliva. In some people, it is thought that alpha-gal then triggers the immune system to produce antibodies directed against this carbohydrate.
Because alpha gal is found in all red meats, including beef, pork, and lamb, the next time the person eats red meat, the alpha-gal activates these antibodies and results in an allergic reaction that, in many cases, has occurred during the night. The reaction typically manifests as delayed urticaria (hives) or delayed anaphylaxis (involving a host of symptoms, including swollen lips, eyes, tongue and throat; respiratory issues; and increased heart rate and low blood pressure). However, some people may experience gastrointestinal symptoms, such as vomiting or diarrhea, without cutaneous features. The key feature of this condition that differentiates it from typical food allergies is the delay of four to six hours, or longer, from consumption of the meat to onset of symptoms, Dr. Commins said.
Dr. Parry graduated from the University of Liverpool, England in 1997 and is a board-certified veterinary pathologist. After 13 years working in academia, she founded Midwest Veterinary Pathology, LLC where she now works as a private consultant. She is passionate about veterinary education and serves on the Indiana Veterinary Medical Association’s Continuing Education Committee. She regularly writes continuing education articles for veterinary organizations and journals, and has also served on the American College of Veterinary Pathologists’ Examination Committee and Education Committee.
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