Looking for a quick way to give up eating meat? The threat of death might do it.
Scientists recently discovered a dangerous allergy to steak, chops and sausages caused by tick bites.
Symptoms of the meat allergy can range from mild hives to nausea and vomiting to severe anaphylaxis, which can turn your toes up.
Scientists are calling the allergy a mystery.
The only clinical insights gleaned so far are from a University of Virginia School of Medicine scientist who has identified the key immunological changes in people who abruptly develop the allergy.
That is, he’s found what happens in the immune system, but not exactly why it’s happening.
“We don’t know what it is about the tick bite that causes the meat allergy. And, in particular, we haven’t really understood the source of immune cells that produce the antibodies that cause the allergic reactions,” said Dr Loren Erickson in a prepared statement.
“There’s no way to prevent or cure this food allergy, so we need to first understand the underlying mechanism that triggers the allergy so we can devise a new therapy.”
People who develop the allergy in response to the bite of the Lone Star tick tend to be caught by surprise – having had a healthy relationship with burgers and grills all their lives.
Once bitten, they usually have to give up eating mammalian meat, including beef and pork, entirely.
Even food that does not appear to contain meat can contain meat-based ingredients that trigger the allergy.
This means people living with the meat allergy must be hyper vigilant – in the same way people with nut allergies are obliged to double-check labelling on foods.
In the US, where much of the research appears to be focused, the allergy is caused by Amblyomma americanum, the Lone Star tick.
But it also occurs in Australia via Ixodes holocyclus, better known as the Australian paralysis tick – which is found in a 20 kilometre-wide strip running north to south along the east coast.
In Europe. the allergy is caused by Ixodes ricinus, the castor bean tick, is a chiefly European species of hard-bodied tick.
Reports are emerging of the allergy appearing in Africa and Japan.
The allergy appears to mainly affect adults, but the University of Virginia (UVA) has seen 45 cases in children.
The allergy was first discovered by the university’s Dr Thomas Platts-Mills, an allergist who determined that people were suffering reactions to a sugar called alpha-gal found in mammalian meat.
Exactly what is happening inside the body, though, has remained poorly understood.
Dr Erickson’s team in UVA’s Department of Microbiology, Immunology and Cancer Biology has found that people with the meat allergy have a distinctive form of immune cells known as B cells, and they have them in great numbers.
These white blood cells produce antibodies that release chemicals that cause the allergic reaction to meat.
According to a statement from the university, Dr Erickson has developed a mouse model of the meat allergy so that scientists can study the allergy more effectively.
“This is the first clinically relevant model that I know of, so now we can go and ask a lot of these important questions,” he said.
“We can actually use this model to identify underlying causes of the meat allergy that may inform human studies.
“So it’s sort of a back-and-forth of experiments that you can do in animal models that you can’t do in humans.
“But you can identify potential mechanisms that could lead to new therapeutic strategies so that we can go back to human subjects and test some of those hypotheses.”
In the meantime, allergy sufferers are eating more chicken and fish.