This tick bite can make you allergic to meat
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Image: CDC Public Image Library

The lone star tick (Amblyomma americanum) is found along the eastern coast of the United States, and is particularly prevalent in the southeastern states such as Tennessee, North Carolina and Virginia. And after being bitten by the species, some unfortunate people are experiencing severe allergic reactions around four to six hours after they eat red meat.

These symptoms include hives, swelling and the sensation of burning, and even anaphylaxis, trouble breathing, vomiting and diarrhoea. So pretty much every meat lover's worst nightmare.

The problem isn’t rare either, scientists at Vanderbilt University Medical Centre were seeing at least one new case of the severe meat allergies each week back in February, they explained in a press release from earlier this year. A paralysis tick in Australia has also been shown to cause meat allergy, and similar cases have been reported in France, Germany, Sweden, Spain, Japan and Korea.

So how does an insect bite cause involuntary vegetarianism? Scientists have found that the tick bite makes patients allergic to alpha-gal, a sugar found in red meat. Normally our stomachs can break down this sugar with no issues - but once it’s introduced into the blood stream, our immune system makes antibodies against it, which attack the sugar next time it’s present anywhere in the body. And that’s what it appears the tick is doing when it bites humans.

"The thought is that the tick has the alpha-gal sugar in its gut and introduces it as part of the allergic bite and that causes the production of the allergy antibody that then cross-reacts to the meat," Robert Valet, a doctor and assistant professor of medicine at Vanderbilt University Medical Centre explained in a press release.

This alpha-gal inside the tick's stomach likely comes from blood it's drunk from other mammals.

"I think it is something that certainly belongs among the most important food allergies, particularly in the Southeast [of the US]," said Valet. "Certainly these patients can present with every bit as severe of an allergy as someone who is allergic to peanuts.”

The patients are still capable of eating poultry and fish, but all red meat including beef, pork and venison will trigger a reaction. Some are also reacting to small amounts of milk, said Valet.

The allergy is currently being diagnosed with a blood test but at the moment there’s no way to stop the response - the best solution is for sufferers to carry an EpiPen in case they’re exposed to red meat and have a severe reaction. Valet told Associated Press that doctors still don’t know how long-lasting the problem will be in patients.