Tick-borne diseases like Lyme disease and Rocky Mountain Spotted Fever are quite frightening enough. Since the turn of the 21st century, doctors have begun to recognize a new hazard from tick bites. It is a delayed allergic reaction to eating red meat that can provoke quite a range of symptoms. Here are some stories from our readers about this scary allergy:
Deadly Lamb Chops:
Q. I almost died from an allergic reaction to lamb chops. I was surprised when my allergist asked about ticks, but told him I had gotten into a nest of seed ticks a year ago. Now I have to avoid all meat. I carry an Epi-Pen just in case I am exposed accidentally.
I have also been avoiding cheese, since it is produced with the use of rennet, an animal product. Am I being overly cautious?
A. You are describing alpha-gal allergy, a condition that is initially triggered by a tick bite. People then develop a delayed allergic reaction to meat, including beef, pork, lamb and even venison or rabbit. Chicken, turkey and fish do not trigger the allergy, which can range from itchy hives to the type of anaphylactic reaction you experienced.
According to the lab at the University of Virginia that uncovered this condition, most patients with alpha-gal allergy are able to eat cheese without reacting. You might want to learn more about this from our one-hour interview with the lead researcher, Dr. Thomas Platts-Mills.
Lone Star Ticks Are Responsible for This Red Meat Allergy:
Q. I have two friends who have developed severe red-meat allergies, one of whom was told by his doctor that it was likely tick-bite related. What can you tell us about this?
A. The condition your friends have developed is called “alpha-gal allergy.” It is triggered by a reaction to a tick bite (Current Opinion in Allergy and Clinical Immunology, online, June 5, 2013). The lone star tick (Amblyomma americanum) is the culprit. Eating beef, pork, lamb, rabbit, venison or buffalo meat can result in a delayed anaphylactic response (3 to 6 hours later).
Children and Red Meat Allergy:
Children are increasingly susceptible and may be hard to diagnose. Children should be checked thoroughly for ticks whenever they come in from playing in woods or grassy areas. Parents and children should use an insect repellent when spending time in areas where there are likely to be ticks to prevent potential a tick bite.
Other Reports from Our Readers:
LB in Chapel Hill, NC, wrote to us:
“I, too, have the alpha-gal allergy and have been allergic to all mammalian meats for about 13 years. A year ago, I began to react to whey but can still eat all other dairy products. My reactions are severe: full body hives and a drop in blood pressure. The reaction starts four hours after I have had a meat product, which of course, I no longer knowingly eat. I have a strong reaction to tick bites. The bite stays red and itchy for a long time-several weeks to months.”
We also heard from RW about the symptoms that plague her:
“Ticks do inflict some horrible conditions! I began having delayed anaphylactic allergic reactions to meat a few years ago and found out it was due to a tick bite! This is production of an allergic class of antibody that binds to a carbohydrate present on meat called galactose-alpha-1,3-galactose, also known as alpha-gal.
“My symptoms, which always occurred in the middle of the night, included hives, heart palpitations, shortness of breath, abdominal cramping, sometimes diarrhea, and twice I passed out. It took me a while to figure out what was going on because I didn’t eat meat often, but this happened almost every time I did. Finally an allergist confirmed the meat allergy, but it was another year or two before I learned about a tick bite being the cause. Now my boyfriend has it too!”
Carrie was not warned that the allergy includes any mammalian meat:
“I am 50 years old and I have recently been diagnosed with a beef allergy. I had indeed been bitten by 20 or so ticks, 2 Lone star or what we call Dog Ticks and the others Seed Ticks, several weeks prior while clearing some land. I was only told that I tested positive for beef and milk. Soon after (giving up all beef and milk) I had another severe reaction this time to pork sausage, in the middle of the night just like the first time; hands and feet burning and itching, hives over most of my body and shallow breathing.
“The Epi-Pen prescribed to me by the ER Doc saved my life. I wish that local PA’s and nursing staff were more aware of this disorder and would have told me it would include all mammal meat. I still have many questions…..If someone could point me in the direction of someone with expertise, Or put them in contact with me, regarding this disorder I would be greatly appreciative!”
M, in Charlotte, NC, had this question:
“I pulled a lone star tick off me in May. I, too, would like to get in touch with an expert who can answer some questions.
“Thanks to the People’s Pharmacy program about the lone star tick, I discovered I might be allergic to meat. I had an inexpensive test done by Dr. Platts Mills’ lab, and have a score of 0.87.
“My doctor, who previously had no awareness of alpha-gal and meat allergy, says the test indicates I have a weak allergy to meat. Does a score of 0.87 mean my hives are due to this allergy? Any stories related to the blood test scores and ranges would be appreciated.”
Liz in Kentucky responded to M:
“Any alpha gal test result above 0.35 is considered ‘positive’ according to the Viracor testing info. So, I would certainly think hives were plausible.
“Everyone reacts in different ways, so I doubt there will ever be a chart established wherein a number range correlates to severity or nature of reactions.
“I personally don’t even get hives. My throat just swells right up and I experience extreme gastro-distress. Waiting on my numbers to come in from Viracor. I react to beef, pork and whey. No problem with other dairy yet.”
We urge all our readers to wear protective clothing and/or insect repellent with either DEET or picaridin when outside in tick territory. Upon returning inside, take off the clothing and do a thorough tick check to remove them as soon as possible. And be alert to the possibility of alpha-gal allergy. North Carolina physicians have written that “patients more often discover a diagnosis of alpha-gal allergy by using information resources on their own than by presenting to the ED with anaphylaxis” (Flaherty et al, Journal of Primary Care and Community Health, April 1, 2017).