Mystery Allergy Strikes Adults

When Linda Quinn awoke in the middle of the night in a Tulsa, Okla., motel room last July, a thousand miles from home, her first thought was, "Not again."

Huge itchy red blotches blanketed her torso. A great weight seemed to be pressing on her chest, pushing air out of her lungs. She felt dizzy, a sure sign of plummeting blood pressure and a hallmark of anaphylaxis—the potentially fatal allergic reaction that had sent her to the emergency room half a dozen times since 2006. She quickly roused her husband, Joseph, who called the front desk. A clerk summoned an ambulance, and Quinn was whisked to a nearby emergency room.

Both Quinns were baffled: Linda hadn't eaten any of the foods doctors warned her to avoid, after being diagnosed with a food allergy. Only later would the retired couple discover that the culprit was something neither had imagined.

Linda Quinn's diagnosis, shared by a growing number of patients around the world, is upending long-held views of food allergies, which held that adults don't tend to develop allergies late in life. And yet these adults, some as old as 80, suddenly developed an allergy that sounded downright bizarre: They were allergic to meat.

A pair of recent studies—one published by a team from the University of Virginia School of Medicine, where Quinn was later treated, and another in Sydney, Australia—are prompting doctors to reconsider the prevalence of this allergy that has been considered rare and to consider a likely trigger that was previously unknown.

"It's really interesting, because it's so unexpected," said physician Wayne Shreffler, director of the Food Allergy Center at Massachusetts General Hospital in Boston.

Saju Eapen, M.D., an allergist in private practice in Roanoke, Va., agrees. Eapen, who calls the finding "transformational," said that he and his partners have referred nearly 150 patients to U.Va. for specialized testing in the past year. "This was not something we looked for in the past."

Unexplained episodes

For Linda Quinn, 61, a former veterinary technician, life in rural Farmville, Va., was just what she and her husband, a former housing inspector, had dreamed of when they left the suburbs of Washington, D.C. They had a horse, a cat, dogs and, they soon learned, a whole lot of ticks.

While the speck-size insects ignored Joe, they gravitated to Quinn, who grew used to plucking the "voracious little buggers" off her clothing or exposed skin after a walk or trip to the barn. She also got used to the inevitable reaction a few hours after a tick bite, when the bite would become swollen and ferociously itchy. But the symptoms always subsided.

In 2006 Quinn began experiencing frightening episodes that seemed related to visits to the barn. At first she thought it might be a reaction to hay or mold. Giant itchy red hives would suddenly appear from her neck to her knees. Sometimes she would have difficulty breathing and would become dizzy, her normally high blood pressure once plummeting as dangerously low as 86/60.

Neither Quinn nor her doctor had any idea what was causing these episodes. Doctors would give her epinephrine and Benadryl to counteract the symptoms, wait for them to subside, then send her home. After several months it became clear that the episodes were becoming more violent and more frequent.

Doctors had no idea what was causing her anaphylaxis. Her doctor told her she needed to always carry an EpiPen, a device that administers an emergency epinephrine injection. In November 2007 he referred her to the University of Virginia's allergy clinic in Charlottesville, headed by Thomas Platts-Mills, M.D., an internationally prominent allergist, for further evaluation.

I think you've got it!

After taking an extensive history, Platts-Mills and his team performed skin tests and discovered something that stunned Quinn: She was highly allergic to beef, as well as pork and lamb. The allergy, which typically surfaces in childhood, is considered rare.

Platts-Mills asked if she ate meat. Every day, she replied.

Had she recently been bitten by ticks and developed a reaction? After Quinn recounted her frequent bites and the inevitable itchy swelling, Platts-Mills shed his British reserve.

"I think you've got it! You've got the real thing!" he told her.

Quinn soon learned that his lab was working on a novel new theory: that an uncommon reaction to tick bites can trigger the development of a sudden allergy to meat in adults like Quinn who have eaten meat for decades without incident. She quickly agreed to join Platts-Mills' study, becoming Patient 15. Several hundred people are now enrolled.