Many Americans May Have Alpha-Gal Syndrome, Not Know It

If eating red meat makes you sick, you may be one of hundreds of thousands of Americans unaware that they have an allergy spread by ticks. In two studies released Thursday, the Centers for Disease Control and Prevention said 110,000 suspected cases of the allergy, alpha-gal syndrome, have been detected through blood tests for antibodies since 2010, but the true number of cases is probably closer to 500,000, the New York Times reports. Some 19,000 people tested positive for the allergy last year alone, researchers say—but 42% of medical professionals surveyed had never heard of alpha-gal syndrome and another 35% were "not too confident" they could diagnose it.

The syndrome's name comes from a sugar found in beef, pork, and meat from most other mammals, as well as milk and other dairy products. The sugar is also present in tick spit, and researchers say it can cause a severe reaction when it enters the body through the skin, leading to alpha-gal syndrome. One reason it may be so under-diagnosed, researchers say, is that symptoms are "consistently inconsistent." Symptoms can include "hives, nausea, vomiting, diarrhea, severe stomach pain, difficulty breathing, dizziness and swelling of the lips, throat, tongue, or eye lids," per the AP. The allergy is spread mainly by the lone star tick, most commonly found in the eastern and southern US, though other ticks may also be culprits.

Unlike most food allergies, symptoms only appear hours after eating. The American Gastroenterological Association says that because some people with the allergy only experience stomach symptoms, people with unexplained diarrhea, nausea, and abdominal pain should get tested. There is no known treatment or cure, though doctors say it fades away in around a fifth of patients. "Alpha-gal syndrome can be a lifelong condition," says CDC disease ecologist and veterinarian Johanna Salzer, per the Times. "It definitely needs to be a part of the conversation of why tick prevention is so important for public health," says Salzer, who worked on both studies. (More ticks stories.)