A severe food allergy in many cases is a straight forward diagnosis for an experienced allergist to make. The key to diagnosing is a comprehensive, detailed history of what the patient ate in relation to the time the allergic reaction occurred.
Peanut allergy, tree nut allergy and shellfish allergy are all highly protein foods and when a person with specific allergy antibodies (IgE) to that food eats any of these types of foods they will notice, typically within seconds, an allergic reaction such as a skin rash, difficulty breathing or loss of consciousness.
Can Meat Cause an Allergy?
Until recently, beef allergy was relatively rare. In most cases, it was associated with children or adults allergic to milk proteins which cross-reacted with the beef proteins. Again, like most IgE mediated allergic reactions this would typically occur within seconds to minutes. An allergist could do a skin test or blood test to confirm the diagnosis to cow’s milk or beef.
What Causes Meat Allergy?
In 2009, a strange new allergic reaction associated with eating beef surfaced. It was strange because people eating beef would get a severe allergic reaction some of the time after eating beef or any mammalian meat (pork) but not every time they ate it. It also was atypical and hard to diagnose since the reaction would occur several hours after the meal.
Fortunately, one of the people that developed this reaction after eating steak and hamburgers was a world-famous allergist in Virginia, Dr. Thomas Platts-Mills. Dr. Platts-Mills developed severe allergic reactions (anaphylaxis) after eating his delicious steak yet when he got himself tested the typical allergy tests were negative. Not one to give up easily, the Dr. Platts-Mills remembered he had been bitten by many ticks the prior summer and wondered if there was a relationship between the two. Also during this time, he was hearing of other reports of cases similar to his at medical meetings.
He teamed up with his lab at the University of Virginia Medical School and made an amazing discovery: people that were bitten by a tick who is a close relative to the Lyme tick developed antibodies to a carbohydrate in meat called alpha-gal galactose. Why was this significant? Alpha-gal is found in the fat of mammalian meat (beef and pork – not chicken) and it gets released several hours after digestion. This delay in release of the alpha-gal explains why the symptoms occur several hours after a person has eaten a meal with beef or pork and not within minutes of consumption like most other food allergy reactions. There is a blood test to check for alpha-gal antibodies through a special lab. I have diagnosed several cases of the Meat Allergy syndrome in my New York City and Long Island practice which makes sense since many New Yorkers vacation on eastern Long Island particularly the Hamptons where ticks run rampant. When I lectured about this allergy condition at the Weill Cornell Otolaryngology Meeting in 2013 most of my colleagues had never heard of the allergy.
If you are concerned you may have meat allergy please make sure you are tested for the alpha-gal antibody. And next time you go for a Hamptons getaway make sure to order some chicken or fish with your vegetables.
– Dr. Dean Mitchell
Mitchell Medical Group | NYC & Long Island