Potential Elevated Risk for Developing Meat Allergies Following a Tick Bite Could be Overlooked
Pesky Ticks Expand the Scope of Meat Allergies
The tick problem is spiraling out of control, with new research suggesting that there are more tick species in the U.S. capable of causing an unusual meat allergy.
Last week, scientists from the Centers for Disease Control and Prevention and local health officials published their findings in the journal Emerging Infectious Diseases. Their research details cases of this strange meat allergy, known as alpha-gal syndrome, linked to bites from two tick species not usually associated with it, including those that transmit Lyme disease. While these instances appear rare, they indicate that the population at risk for this syndrome might be larger than previously presumed.
Alpha-gal, a sugar found in the muscles of most mammals, doesn't pose a problem for us when we consume it in our meals. However, for reasons yet to be fully understood, a tick bite can trigger an overactive immune response to alpha-gal, making us allergic to red meat and even dairy products. This allergy type is unique since it's the only food allergy involving a sugar (alpha-gal) rather than a protein, and symptoms might not show up for hours after exposure.
In the U.S., cases of alpha-gal syndrome are typically linked to the bite of the notorious lone star tick (Amblyomma americanum), found predominantly in the eastern half of the country. But research has found Alpha-gal instances outside the conventional description and patterns, hinting at the involvement of other tick species.
In one study, researchers documented a woman in Washington who suffered from alpha-gal after a bite from an unspecified tick species in 2017. She subsequently switched to a vegetarian diet but still experienced rises in alpha-gal antibodies following subsequent tick bites from Ixodes pacificus, or the western black-legged tick, in 2017 and 2019. Interestingly, she had no recent travel history to areas where the lone star tick is prevalent.
In a another study, scientists traced back an alpha-gal case in Maine to the bite of an Ixodes scapularis tick, or deer tick. While lone star ticks are seldom reported in Maine, they're believed not to have established a local population in the area. Even so, they uncovered 23 confirmed cases of red meat allergy reported to the state dating back to 2014, with several cases involving no travel history to endemic lone star tick regions.
Both Ixodes ticks have a wide distribution across U.S regions and are already known for spreading diseases like Lyme disease. Although cases of alpha-gal attributed to Ixodes ticks might be less common, the overall occurrence of alpha-gal syndrome is on the rise. A 2023 study by the CDC and others estimated that approximately 450,000 Americans have developed alpha-gal syndrome since 2010, with rates possibly increasing throughout the years.
Therefore, if other ticks can cause this condition, people and healthcare providers in regions where it isn’t traditionally found should stay vigilant, the researchers advise.
[1] Genovese SA, Yee BW, DAVIS LK et al. Alpha-gal allergies: Causes, diagnosis, and potential treatments. Journal of allergy and clinical immunology, 2021, 148(3): 748-759.e3
[2] Zajac JP, Demeter JL, Chipman CW et al. Emergence of human IgE antibodies to tick-borne Alpha-gal following lone star tick encounters. PLoS ONE, 2011, 6(7): e22527.
[3] Demeter JL, Berard A, Saff TM et al. Serological evidence of human sensitization to α-gal connects western black-legged ticks, lone star ticks, and red meat allergy. Journal of allergy and clinical immunology, 2014, 133(2): 464-471.e3.
- Technology, particularly in the field of science, might provide solutions for understanding the causes of alpha-gal syndrome, a tick-induced health issue that could be spread by various tick species in the future.
- The confirmation of cases of alpha-gal syndrome linked to tick bites from species like Ixodes pacificus and Ixodes scapularis highlights the need for prevention measures against more tick species beyond those traditionally associated with the syndrome.
- Symptoms of alpha-gal allergy can appear hours after exposure and might not always be linked to known endemic areas, making it crucial for healthcare providers and the public to stay informed about the expanding range of ticks capable of causing this condition.
- As research continues to uncover the involvement of other tick species in the rise of alpha-gal syndrome, it is essential to invest in science and technology to develop the necessary tools for early detection and effective treatment of this unique food allergy.
