Meat allergy triggered by a tick bite

The dorsal view of a female “lone star tick.”

Retired physician and outdoorsman Frank Middleton is familiar with both infectious diseases and tick bites.

But one thing he had not been familiar with was an allergy to red meat triggered by the bite of the lone star tick, which can be found across the Southeast, until after he had become a victim himself.

The 76-year-old Wadmalaw Island resident recalls being bitten by a tick on the thigh about two years ago. He removed it, but soon developed swollen lymph nodes.

Thinking it was Rocky Mountain spotted fever, he was treated with antibiotics and his symptoms went away.

Months later, Middleton started having episodes of hives that became more severe, but he usually couldn’t associate the breakouts with anything that he was exposed to or ate.

One night, he and his wife were spending the night in Columbia, where he had enjoyed a filet mignon at a prominent chain steak house for dinner, and he suffered a breakout in the middle of the night. He blamed it on the sheets in the hotel.

The final straw came during a trip to Wyoming last summer when he suffered an anaphylactic reaction that left him unable to talk temporarily. It had been hours after he had eaten two servings of sausage on an airplane flight.

He went to Charleston Allergy & Asthma to have some tests done and told his story to Dr. Thomas Harper III, who suspected that he may have a tick-borne allergy known as “Alpha-gal.” First formally identified in 2009, the allergy’s name refers to the reaction to a carbohydrate, Galactose-alpha-1, 3-galactose.

“I did the testing and he had a very high positive,” says Harper, referring to the antibodies that react to the carbohydrate.

Harper says the allergy had probably been around for years before being identified, in part, because of the delayed reaction between eating meat and the outbreak. That’s due to the time required to digest the meat before the reaction occurs.

“It (the allergy) was harder to pick up on because of the delay, which is not the case with most. If someone has a peanut allergy, after you eat them, you break out. That’s a no brainer,” says Harper.

The allergy applies to certain meats — beef, pork, lamb, rabbit, venison and bison — along with cow’s milk and products such as gelatin, but not chicken, turkey, duck or fish.

Middleton stopped eating the specified meat products and hasn’t broken out since then. He also lost 10 pounds.

“I’ve told my friends that I’ve been forced to eat a healthy diet,” jokes Middleton, adding the question remains if he’ll ever be able to resume eating those meat products.

Harper says each of the six allergy specialists at the practice has diagnosed cases of the Alpha-gal allergy.

“I think we’re seeing more cases because we now know to look for them,” says Harper

The prevalence, however, is still relatively unknown.

The Centers for Disease Control and Prevention doesn’t have data on the number of people who have developed the allergy. But one expert at the University of North Carolina at Chapel Hill, interviewed by “The Today Show,” is urging caution to those who live in places where the lone star tick is common.

“We know at this point that there are over 3,500 cases,” says Dr. Scott Commins, an associate professor of medicine and pediatrics in the division of rheumatology, allergy & immunology at UNC’s Thurston Research Center. “I think there are many more.”

Commins adds that he knows of one practice in Kentucky that has more than 100 cases and another group near Savannah, with more than 50 cases. He estimates that up to 5 percent of the population in tick areas will get the allergy.

Reach David Quick at 937-5516.