Red meat allergies from a lone star tick bite? I first read about this a few years ago in Science Daily and it seemed pretty incredible - eat some red meat (beef, pork, or venison) and a few hours later have severe allergy symptoms such as itching, hives, swelling, shortness of breath, vomiting, and diarrhea. And the allergy starts after a person is bitten by a lone star tick.
A few years ago the red meat allergy seemed to occur only in the southeastern United States. But recently the severe red meat allergies are occurring in new places (such as Minnesota and Long island, NY) - so it appears that either the area where this tick lives is spreading or other species of ticks are also now causing this allergy. By the way, once a person has this allergy there is no cure, vaccine, or treatment other than avoiding red meat, treating the allergy symptoms, and carrying an EpiPen (just in case). It is also referred to as Alpha-Gal allergy syndrome because the allergy is to the sugar molecule commonly called alpha-gal which is found in red meat and some medications (such as the cancer drug cetuximab). From Wired:
First comes the unscratchable itching, and the angry blossoming of hives. Then stomach cramping, and—for the unluckiest few—difficulty breathing, passing out, and even death. In the last decade and a half, thousands of previously protein-loving Americans have developed a dangerous allergy to meat. And they all have one thing in common: the lone star tick.
Red meat, you might be surprised to know, isn’t totally sugar-free. It contains a few protein-linked saccharides, including one called galactose-alpha-1,3-galactose, or alpha-gal, for short. More and more people are learning this the hard way, when they suddenly develop a life-threatening allergy to that pesky sugar molecule after a tick bite.
Yep, one bite from the lone star tick—which gets its name from the Texas-shaped splash of white on its back—is enough to reprogram your immune system to forever reject even the smallest nibble of perfectly crisped bacon. For years, physicians and researchers only reported the allergy in places the lone star tick calls home, namely the southeastern United States. But recently it’s started to spread. The newest hot spots? Duluth, Minnesota, Hanover, New Hampshire, and the eastern tip of Long Island, where at least 100 cases have been reported in the last year. Scientists are racing to trace its spread, to understand if the lone star tick is expanding into new territories, or if other species of ticks are now causing the allergy.
Over the next few years Platts-Mills and his colleague Scott Commins screened more meat allergy patients and discovered that 80 percent reported being bitten by a tick.What’s more, they showed that tick bites led to a 20-fold increase in alpha-gal antibodies. Since ethics standards prevented them from attaching ticks to randomized groups of patients, this data was the best they could do to guess how meat allergy arises. Something in the tick’s saliva hijacks humans’ immune systems, red-flagging alpha-gal, and triggering the massive release of histamines whenever red meat is consumed.Researchers are still trying to find what that something is.
Whatever it is, allergy researchers will be paying attention. Because, as far as anyone can tell, alpha-gal syndrome seems to be the only allergy that affects all people, regardless of genetic makeup. “There’s something really special about this tick,” says Jeff Wilson, an asthma, allergy, and immunology fellow in Platts-Mills’ group. Usually a mix of genes and environmental factors combine to create allergies. But when it comes to the lone star tick it doesn’t matter if you’re predisposed or not. “Just a few bites and you can render anyone really, really allergic,” he says.
Lone star tick Credit: CDC Public Image Library