Ticks causing mysterious meat allergy
By Olivia Smith, CNN
updated 10:25 AM EDT, Wed June 20, 2012
(CNN) -- Helen Olive had her first allergy attack 11 years ago. She had gone to bed only to wake up hours later because her neck felt as if it were on fire.
"It was terrible," said Olive, who is 42 and lives in North Carolina. "The sensation was all over my body and then I developed hives."
A slender woman with wavy, reddish-brown hair and blue eyes, Olive might appear perfectly healthy. But waking up in the middle of the night with uncontrollable itching and nausea became a common theme in her life.
She was driving her motorcycle around town with her husband on a hot summer day in 2008 when they decided to stop for a meal at a local restaurant. "I had a black and blue salad with beef tips," Olive said. "Later I had the same reaction except the Benadryl would not work."
As her symptoms continued to increase, she made an appointment with the Carolina Asthma and Allergy Center. Her blood test showed that she was very allergic to meat. Olive's doctor informed her that a meat allergy was "not common."
But two allergists at the University of Virginia have gathered data showing that the food allergy Olive has, known as galactose-alpha-1,3-galactose, or alpha-gal for short, is affecting more than 1,500 Americans. The researchers suspect there are many more unidentified cases.
"The answer to the allergy is sugar," said Dr. Thomas Platts-Mills, who discovered the allergy with his junior colleague Dr. Scott Commins. They first published their findings in 2009.
Alpha-gal is essentially a bunch of sugars stuck together in the blood, which is in the meat of all non-primate mammals, including deer, cats and dogs. "We have seen anaphylaxis in France with horse and goat meat as well," Platts-Mills said.
What causes the allergy may be surprising.
All known patients who have alpha-gal have had at least one tick bite. Platts-Mills, who also suffers from alpha-gal, made the connection after receiving countless bites while hiking in the woods one August. As a result, his level of IgE, which measures the alpha-gal allergy in one's blood, went up several-hundred points. That is when Platts-Mills concluded there is some relation to the number of tick bites one receives and how allergic one may become to alpha-gal.
Platts-Mills and Commins said the allergic reaction is specifically related to the common lone star tick (Amblyomma americanum). These ticks cover various plains across the United States. An important distinction is that alpha-gal is not a disease like Lyme disease or Rocky Mountain spotted fever -- it is an allergy.
"Presumably something happened with the ticks," said Platts-Mills. "It could possibly be a new tick spreading."
The doctors believe the allergy could more closely be related to bites that come from tick larva, or baby ticks.
"Perhaps there is an organism in the tick's saliva that makes a person allergic to the alpha-gal sugar in mammalian meat," Commins said.
For meat lovers, especially hunters, the simplest solution is to avoid ticks -- as if that's an easy thing to do.
And what if you've already been bitten? Olive doesn't fancy the idea of eating a steak with an epinephrine auto-injector, which treats life-threatening allergic reactions.
Allergist Dr. Erin McGintee who practices in the Hamptons has seen some dangerous cases of alpha-gal in New York, including a few patients who passed out in their bathrooms.
"Intellectually, it's such a cool allergy on so many levels," McGintee said. "It's a sugar, not a protein, and most food allergies occur in response to a protein antigen."
Alpha-gal is unique in that it is the first known case of delayed anaphylaxis, she said. While anaphylaxis normally occurs within minutes or seconds of eating a certain food, this is not the case with alpha-gal patients, who suffer anaphylactic shock anywhere from four to six hours after eating certain meats. Most who suffer from alpha-gal can attest that waking up in the middle of the night, not from a nightmare, but from anaphylaxis, is quite frightening.
Alpha-gal's reactions vary on a case-by-case basis, sometimes with a patient experiencing a severe reaction and other times nothing at all. Doctors advise that people who are exposed to lone star ticks should be aware of the allergy, especially if they live in the country, where it could take some time to reach a hospital.
Jaime Johnston, 62, has lived in parts of North and South Carolina, and had her first tick bite when she was 5. She was about 46 when she became severely allergic to meat. Like many others, she had alpha-gal before it was even named. It has taken her almost 20 years to understand that her meat allergy is connected to ticks. However, she did learn early on that certain meats were her enemy.
"No doctor has ever taken this claim seriously," Johnston said. Doctor's "would roll their eyes and tell me to go to an allergist.[/dolor] I've never done this because of the anticipated costs."
A trip to an allergist could cost a few hundred dollars without insurance.
While some daredevils may want to risk it and enjoy a juicy steak regardless of their alpha-gal allergy, the only true way to avoid an allergy attack is to avoid the food itself. "There is no current medication to treat food allergies," Commins said.
However, Commins did explain that if a person were to avoid tick bites for some time, he or she could become less allergic to meat.
"For those lucky few who have had their (IgE) levels fall, we try a meat challenge to 'clear' them to consume mammalian meat."
Yet be warned, additional bites could once again lead to anaphylactic shock. And to some, the meat challenge just doesn't seem worth it.
"I don't want to risk it," Olive said. "We have six acres and some of it is woods. Ticks are really unavoidable."
Camp Other posted this link to a similar article in his blog entry dated Saturday, July 23, 2011:
http://www.necn.com/07/23/11/NC-teen-de ... 59f1aae82f
NC teen develops mysterious meat allergy
Jul 23, 2011 12:00am
ELIZABETH CITY, N.C. (AP) — About a year ago, 15-year-old Andrew Treadway of Currituck got a tick bite while camping near Charlottesville, Va.
The bite did not appear serious. When he returned to his Moyock home, his mom looked for the tell-tale bulls-eye rash indicating Lyme disease and the flulike symptoms from Rocky Mountain spotted fever, but all appeared normal.
Little did they know that the tick bite would later trigger an allergy to red meat. Today, the Treadways want others to know about the newly discovered allergy that puzzled their family for months.
Making the connection between the tick bite and the allergy was not easy. Several months after the tick bite, the teenager began complaining of unexplained stomach aches and migraines. Ann Treadway said she was baffled by what was causing the problem.
The real alarm came a little later when the family went camping with friends.
Andrew ate nachos for dinner and later played ultimate hide-and-seek with his friends. While hiding in the dark, he remembered putting his hand on something watery. Later, doctors would suspect it was poison ivy or poison oak.
At about 1 a.m., Andrew awoke to itching. He asked his parents to look at his back, which was covered in welts. His face and ears were swollen and lobster red, and his eyes were puffy.
His parents took him to the emergency room at Chesapeake General Hospital, Va., where he was treated immediately for anaphylaxis, an acute allergic reaction that can be fatal.
"They knew just looking at him, something was bad," said Ann Treadway.
At that point, the family had no clue what caused the allergic reaction and doctors surmised exposure to an outdoor plant was probably the trigger.
The next time, Andrew broke out in hives at a completely different setting. This time he was shopping with his family in New York's Times Square after having eaten at Olive Garden. A rash broke out on his neck and all over his back. The family treated him with Benadryl and Pepcid for his stomach ache.
After that episode, the family began to suspect he had a food allergy, possibly to cheese since Andrew had eaten cheese ravioli at the restaurant. They did not suspect a soup with sausage and beef broth had actually caused the reaction.
"While we were looking at one thing, it was actually another," Andrew recalled.
Andrew said he never remembered having an allergic reaction prior to the two outbreaks, although his parents said he had a reaction to pineapple as a child.
Never did the family even guess that the red meat was the cause. In fact, Andrew had eaten pork and beef often without any apparent effect.
After Andrew's third outbreak after he ate two helpings of meat loaf, emergency room doctors advised he see an allergist.
Allergist Ron Purcell at Portsmouth Naval Hospital, Va., said Andrew's case was the first he diagnosed, although he may have seen other cases earlier without knowing it. He learned about the newly identified red meat allergy related to tick bites a couple months before their visit.
"I may have seen it in the past and not known because it is a newly found connection," Purcell said.
Andrew said he didn't believe the doctor when he first suggested the idea.
Dr. Scott Commins of University of Virginia is credited with discovering the connection between tick bites and the red meat allergy only a couple years ago. Unlike Lyme disease and Rocky Mountain spotted fever, the condition is not considered a disease. Rather, the tick's saliva is suspected of triggering an allergic reaction that results in hives or anaphylaxis.
For Andrew, the severe allergic reaction was triggered only when he ate heavy doses of red meat. Purcell said the triggers for other patients could be different. For example, one patient may be able to eat pork chops but not bacon, he explained.
"We are not always sure what the tipping point is," said Purcell.
Finding out how many North Carolina residents have been diagnosed with the problem is not easy.
Barry Engber, medical entomologist for the N.C. Division of Environmental Health, said the state keeps records on cases of Rocky Mountain spotted fever and Lyme disease, but has no figures for the newly discovered allergic reactions.
A regional allergy center in the Roanoke and Lynchburg, Va., area reported more than 200 cases in two years, according to an article in the Roanoke Times.
Engber said most likely only a small percentage of people bit by the ticks actually develop the allergy.
The tick suspected of causing the allergy — known as the Lone Star tick — is the most commonly found human-biting tick in eastern North Carolina, he said.
"If it was just the Lone Star tick that caused the allergy, everybody would have it," said Engber.
Purcell agreed that only a small number of people bitten by the tick will actually develop the allergy. He said patients who have other allergies are the most susceptible.
The discovery will be valuable in helping doctors and patients identify the often unknown causes for allergies, said Purcell. He believes he's already identified another case since Andrew was diagnosed.
The causes for about a fourth of severe allergic reactions are unknown, he said. The newly discovered allergy will be one more tool for doctors and patients to consider when searching for the cause.
"When you can put something like this together . and see what you can do to avoid it in the future, that's a win," said Purcell.
For Andrew, the mystery has been solved, although living with this newly found knowledge will not be easy.
He can still eat red meat in small quantities. He's been known to sneak a piece of prime rib on his plate at a buffet. But he limits himself to a bite or two before switching to chicken and fish. Aside from avoiding big servings of red meat, there is no cure.
Ann Treadway said there is a chance he may outgrow the allergy. Only time will tell.
"It's such a new thing, they just don't know," she said.
While they wait, she's hoping to spread the word to other families who may not know the answer to the recently unraveled medical mystery.