Red Meat Allergy Symptoms: Alpha-gal Syndrome
Red Meat Allergy
Red meat allergy, though rare, has been on the rise in recent years. This is partly due to the spread of the acquired form of the allergy and partly because of increased awareness of the condition.
Unlike intolerance to meat, an allergic reaction involves the immune system, which produces IgE antibodies against the protein or carbohydrate found in meat deemed “dangerous” by the hypersensitized organism.
On our page, you can learn more about red meat intolerance and the differences between red meat allergy and intolerance.
Red meat allergy, also known as mammalian meat allergy, presents itself in three main forms: primary beef allergy, pork-cat syndrome, and alpha-gal syndrome (1).
Alpha-gal Syndrome
The alpha-gal syndrome is an acquired delayed allergic reaction to a carbohydrate called galactose-α-1,3-galactose, found in mammalian products, such as red meat, milk, gelatin, and others. This is the most widespread type of red meat allergy.
Alpha-gal syndrome, and consequently red meat allergy, is caused by the bite of the Lone Star tick. This tick is indigenous to the eastern parts of the United States. This allergy is spread in parts of Europe, Asia, and Australia by other ticks.
People with alpha-gal syndrome can have severe allergic reactions after consuming beef, pork, venison, rabbit, and lamb, as well as dairy products, protein powder, gelatin, and the cancer drug Cetuximab (3).
Symptoms of the alpha-gal syndrome do not appear immediately after consumption of red meat, as they do with other allergies. Symptoms usually occur 2 to 6 hours after eating red meat, even in large quantities.
Common symptoms are hives, abdominal cramps or pain, and an anaphylactic reaction. Other symptoms include nausea and vomiting, diarrhea, difficulty breathing, swelling of the lips, tongue, and throat, drop in blood pressure, and faintness.
Like other food allergies, a red meat allergy is usually diagnosed through a combination of the individual’s history, skin prick testing, and specific blood tests.
There is no certain treatment for this allergy. It is recommended that people who are allergic avoid red meat and carry an epinephrine pen with them at all times. There is, however, a possibility that red meat sensitivity may diminish over time.
Primary Beef Allergy
Primary beef allergy is predominantly seen in children predisposed to allergic skin reactions and is commonly accompanied by a milk allergy.
This allergic reaction is caused by a protein called bovine immunoglobulin, found both in the muscle and milk of cows.
Symptoms occur soon after beef consumption and include nausea, vomiting, hives, and in rare cases, anaphylaxis.
In some people, cross-reactivity can be present in other red meats, such as pork or lamb.
Over the years, primary beef allergy symptoms can lessen, and gradually tolerance to beef can develop.
Pork-cat Syndrome
The name of this syndrome gives a good idea of the condition: people allergic to cats can develop pork and sometimes beef allergies. This syndrome is seen more commonly in teenagers and young adults.
People with this syndrome get sensitized to cat serum albumin through the respiratory tract but allergically cross-react to ingested pork serum albumin.
A similar syndrome has been reported where an individual with dog allergies developed an allergy to horse meat (2).
Well-cooked pork is less likely to cause a severe allergic reaction.
References
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6488443/
- https://www.researchgate.net/publication/303094324
- https://www.vdh.virginia.gov/epidemiology/epidemiology-fact-sheets
