Val Smith was on a river cruise in France when she woke up in the early hours of the morning feeling incredibly itchy on her arms, torso, and legs. “I felt agony,” recalls the former family support worker who lives in Holbury, Hampshire.
“I couldn’t sleep, so I walked to the main lounge of the ship and sat there itching all night. I kept thinking, what has caused this?
It wasn’t the first time her skin had reacted this way: a few weeks earlier, Val, now 74, had gone to bed feeling very unwell. “I woke up itchy and felt like I’d been bitten by 1,000 mosquitoes,” she says. His body was covered in hives and hives so he took an antihistamine. “The next morning he was gone.”
A week later the same thing happened, again at dawn.
After the third time, on the 2018 cruise, he discovered that he had eaten beef each time that night.
She searched online and found posts about alpha-gal syndrome, a condition caused by a tick bite that causes an allergy to red meat. Val instantly thought of the tick bite she had gotten seven years earlier.
At the time, Val and her husband Les, now 82, had recently moved to the New Forest to be near their family. “I had built a den with my grandson and the next day I noticed a small red mark the size of a mosquito on my knee.”
The bite grew larger, causing swelling “like a plate wrapped around my knee: huge, round and red,” he says.
Val Smith, 74, suffers from alpha-gal syndrome, a disease caused by a tick bite that causes an allergy to red meat.
A couple of months later, with the bite still swollen, she visited her primary care doctor, who sent her to the local hospital to be tested for Lyme disease, an infection caused by ticks carrying the borrelia bacteria.
If treatment (usually antibiotics) is delayed or left untreated, it can lead to joint pain, memory problems, and other debilitating symptoms. The test confirmed that Val had Lyme.
What he didn’t know was that, in addition to causing his leg to swell, the infection triggered an immune response called alpha-gal syndrome (AGS), a meat allergy that can be triggered after someone is bitten by a carrying tick. of alpha. -gal, a type of sugar molecule, in your saliva.
In response, some people produce antibodies against alpha-gal, “in which case we call the person ‘sensitized’,” explains Andrew Whyte, an allergist and immunologist at Derriford Hospital, Plymouth.
“The alpha-gal molecule is also present in the muscles of all mammals except humans and most primates, so a sensitized person can have a reaction to alpha-gal when eating red meat.”
AGS, he says, “has no relation” to Lyme disease, which is “an infection rather than an allergy.”
In the United States, during testing between 2010 and 2022, more than 110,000 people tested positive for alpha-gal antibodies, according to the Centers for Disease Control and Prevention in July, although the true number is believed to be closer. at 500,000. with cases on the rise.
While there are no figures in the UK, “it’s probably more common than we think as the diagnosis is often missed, but specialists are seeing more cases,” says Dr Whyte.
And he adds: “The onset of AGS after a tick bite is usually four to six weeks, but in some cases it can take months, although we do not know why.” Of course, if there is a very long delay, the person may have been bitten by a tick but not realized it.’
Another characteristic of AGS is that symptoms may be delayed for a few hours after eating red meat. “Normally, an allergic reaction occurs within an hour of eating (the food that causes it), but in AGS it can often last up to four to six hours,” says Dr. Whyte.
In Val’s case, the reactions occurred about seven hours later.
AGS is most common in the southern and southeastern regions of the US, where a specific tick, called a lone star, is “the source of alpha-gal transfer to humans,” says Dr. Whyte.
It has also been reported in many other countries, adds Professor Hasan Arshad, Professor of Allergy and Clinical Immunology, Clinical and Experimental Sciences at the University of Southampton.
The symptoms of AGS can range from mild (such as a rash and swelling) to severe, including difficulty breathing and anaphylaxis, where blood pressure drops dangerously and organs can fail. “But it is quite possible that you have sensitization to alpha-gal and do not react or do not have any clinical manifestations,” says Professor Arshad.
Alpha-gal syndrome is a condition caused by a tick bite that causes an allergy to red meat.
Although alpha-gal is primarily found in “mammal” meat (i.e., not chicken) and organs (e.g., kidneys), milk and gelatin can also contain it, he explains. “Therefore, medications and vaccines and even sweets that contain mammalian cells or tissues or even a small amount of gelatin can occasionally cause a reaction.”
He adds: “People with blood groups A and O have been reported to be at increased risk and blood group B is protected.” This is because people with blood groups A and O have antibodies that can react to alpha-gal, he explains.
When a person with AGS eats red meat, their reaction may be delayed if they eat fatty cuts instead of lean cuts (since it takes longer to digest fats).
Many people with AGS “may have mild symptoms and never have been diagnosed,” adds Professor Arshad. ‘And there may even be some patients with severe symptoms who suffer from anaphylaxis but whose anaphylaxis has been diagnosed as idiopathic (without any discernible cause) rather than meat-related, as the reaction occurs several hours after consumption of the food.
“In approximately 30 percent of people with anaphylaxis, the cause is not identified,” he says.
Professor Arshad adds that “diagnosis is often delayed because the disease is rare and allergy as a subject is not well taught in medical schools.” But once AGS is suspected, diagnosis is “relatively easy” with a blood test that can be carried out by a GP.
After the cruise, Val went to her family doctor, who told her that she “probably had a heat rash.” “It wasn’t until I got home that I realized I should have mentioned AGS, so I called and asked if he had heard of it.”
His doctor replied that he was “not in the UK”. In fact, while the condition was originally identified in the US in 2002, the UK is among the many other countries where it has now been found.
Dr Whyte says: “While Lone Star ticks are primarily responsible for AGS in North and Central America, other species may be implicated in other parts of the world.”
Val continued to eat meat, but noticed that the reaction was starting to occur ‘even when I ate pork and sausages or bacon, anything that had four legs!’ she says. “I would have worse and worse skin reactions.”
Later in 2018, Val insisted on being referred to an allergist. A blood test showed she had AGS grade 4, meaning she is “very positive” (the scale goes from one, “equivocal,” to four). “That explains why he reacted so badly every time,” he says.
She was referred to the immunology department at her hospital, where she was warned that the reaction may worsen and prescribed an EpiPen (a device loaded with an injection of adrenaline to reduce severe allergic reactions).
He was told to avoid all red meat. “This applies to anything from a mammal, like gelatin or fat. Many foods contain them, such as certain sweets, desserts and even toothpaste, as well as some vaccines, so I have to be very careful.’
As Professor Arshad explains: “There is no cure for alpha-gal syndrome, so affected people should strictly avoid meat.”
He said life can be difficult for those with a severe allergy. “The reaction can occur even with small amounts of meat or even with inhalation of fumes when meat is cooked, as alpha-gal molecules in the air can be inhaled.”
Val adds: “It’s very difficult at hotel buffets as there can be cross contamination from spoons and utensils and I have to check the food labels on everything.”
‘I thought the idea of a tick causing all this was ridiculous and I was going crazy. I hope my story raises awareness that AGS is in the UK.’