This allergy to red meat can be fatal and is unusual in that it creates a delayed anaphylactic response rather than the immediate symptoms of allergies seen with many other foods. Is your beef-burger going to kill you? If you’ve had a recent tick bite then perhaps that veggie burger really is a better option.
UPDATE: A study published last week also documented the new, potentially fatal, tick-caused meat allergy, adding to the evidence that something strange is going on in the southern US.
Delayed Symptoms of this Novel Meat Allergy
The newly discovered allergy is to a sugar found in the flesh of almost all non-primate mammals. This sugar, galactose-alpha-1,3-galactose (or alpha-gal as it is being referred to) can trigger an allergic reaction that results in an itchy rash, throat swelling, dangerously low blood pressure and even death through respiratory failure. Such symptoms of anaphylactic shock usually occur within minutes of eating the food allergen but this alpha-gal allergy can, instead, develop hours after a sufferer eats a beefsteak, meaning that many do not connect their symptoms to the food they have eaten. Many patients require immediate hospitalization and epinephrine shots as the body undergoes this profound allergic response to meat. Some sufferers noted that their first symptoms could be treated with antihistamines but that the reaction gradually got worse until these drugs no longer worked and they required hospitalization. Others seemingly develop the allergy after a single tick bite and suffer an immediate and dangerous allergic reaction to mammal meat.
Recovery After Meat Allergy
The Lone Star tick (Amblyomma americanum) appears to be the cause of the sudden allergy as all the known victims have had at least one tick bite. This has scientists baffled, however, as no one quite understands how the tick bite creates this novel allergy to alpha-gal. Some sufferers have gradually recovered their tolerance to alpha-gal and researchers have devised a ‘meat test’ to check if patients are safe to eat meat again. The scientists who discovered the meat allergy in 2009, Dr. Scott Commins and colleague Dr. Thomas Platts-Mills, stress that there is no cure for such an allergy and the only treatment is to give up red meat.
Tick Bites, Hives, and Meat Allergy
The University of Virginia researchers also noted that the unusual delay of the allergy symptoms is a sign of a new form of food allergy, producing hives and other symptoms four hours or so after eating red meat such as beef, pork, or lamb. The hives are apparently extremely itchy and produce an intense burning sensation in the skin, symptoms which author John Grisham spent three years suffering until he isolated the cause of his symptoms as an allergy to meat caused after a tick bite on his plantation in Charlottesville.
Tick Saliva and IgE Levels
The researchers who uncovered the potential connection between tick bites and meat allergies are still working on finding the mechanism for the unusual condition. Commins found that a single bite from a Lone Star tick triggered an elevation in antibodies in the blood for alpha-gal. Studies using tick saliva are underway to try to figure out what lies behind this strange meat allergy which has also caused allergies in France in those eating horse and goat meat. Platts-Mills has the allergy himself and the researcher made the connection between tick bites and alpha-gal as he saw his IgE level skyrocket after numerous tick bites whilst hiking one year.
Cancer Drug Allergy Connected to Tick Bites
In the paper Commins and Platts-Mills, et al, published in the Journal of Allergy and Clinical Immunology it was also noted that an unusual allergic response to a drug used in cancer treatment, cetuximab, appeared to be isolated to a specific region in the southeast including Tennessee, North Carolina, Arkansas, Virginia, and the southern half of Missouri. This made the researchers suspect involvement of fungi specific to the region, or a regional helminth, before noting that many of the sufferers reported a history of tick bites.
Hunters at Risk of Meat Allergy
Although the ticks that purportedly trigger this meat allergy are not the same as those that carry Lyme disease the spread of ticks across the US poses problems for meat-lovers, especially hunters. The irony is that those very people taking part in bloodsports are the ones most likely to encounter ticks, meaning that the animals they have hunted and killed could then see some vengeance from beyond the grave as their barbecued flesh triggers a deadly anaphylaxis in the hunter.
Avoiding Meat Allergy by Avoiding Ticks
Baby ticks or larvae are thought to be at the center of this new allergy riddle, whereas nymphal ticks or adult blacklegged ticks are those responsible for the majority of Lyme disease cases. Those exposed to ticks on a regular basis are being warned to try to reduce such exposure by using tick-repellents and covering the skin. Unlike Lyme disease transmission, which usually requires the tick to be in place for a day or more, this alpha-gal allergy could develop quickly if the organism responsible is in the tick’s saliva rather than its gut. Those living out in the country without immediate access to emergency medical attention are at particular risk as the Lone Star ticks spread across the US. Prodigious use of tick-repellent, careful checking of clothing, skin, pets, and your gear after spending time outdoors, and avoidance of known tick-infested areas is probably the safest way to avoid developing this allergy to meat after tick bites – otherwise that barbecue might have to be filled with veggies instead this summer.
Scott P. Commins, et al, The relevance of tick bites to the production of IgE antibodies to the mammalian oligosaccharide galactose-α-1,3-galactose, J Allergy Clin Immunol. 2011 May; 127(5): 1286–1293.e6.