What is alpha gal allergy?

  • Alpha gal allergy is known an allergic reaction towards red meat.
  • It usually causes an anaphylactic and hypersensitivity reactions when a person eats meat.
  • The  term alpha-gal is short for galactose-alpha-1, 3-galactose, a carbohydrate molecule that can cause an allergic reaction in people with an alpha-gal allergy.
  • The molecule is found in the meat of mammals, including cows, sheep, venison, bison, and pigs. Alpha-gal allergy is chiefly spread by the bite of the Lone Star tick. It is  named so  for the marking on its back.

All about the alpha gal allergy and its causative agent:-

  • It was known to be first observed by the Allergy researcher Thomas Platts-Mills of the University of Virginia  in 2002 after discovering an allergic reaction to the cancer drug cetuximab.
  • Cetuximab is known to contain the same alpha-gal sugar as meat, although the association was not made with tick bites until Platts-Mills himself was later bitten by ticks and developed the allergy.
  • The Lone star tick is known to be the animal that is identified as the causative agent. Although their tick bites are not significant to the cause, they are known to solely responsible for 80 percent of the cases.
  • In the United States, the Lone Star tick is most common in Southeast Texas, Iowa, and New England. However, cases of the allergy have been noted in other parts of the country, including Hawaii, where the tick does not typically live.

How does it enter the body?

When alpha-gal enters the body, via a tick bite or otherwise, the immune system produces antibodies to fight the molecule.It is still  unclear  as to  what substance in the tick’s saliva causes the development of alpha-gal antibodies.


Mostly people suffer from an allergic reaction after eating red meat. Other common reactions are as follows:-

  1. stuffy or running nose
  2. feeling nauseated
  3. vomiting
  4. developing hives or a rash on the skin
  5. sneezing
  6. headaches
  7. shortness of breath
  8. indigestion
  9. diarrhea
  10. asthma
  11. Anaphylaxis           
  • An anaphylactic reaction restricts breathing and can be fatal, so it needs immediate medical treatment. Although rare, it has been known for people with an alpha-gal allergy to be admitted to the intensive care unit (ICU).
  • In some instances, it can take up to 4 to 6 hours after eating red meat before a reaction occurs. So, people with an alpha-gal allergy do not always associate the reaction with what they have eaten. Symptoms do not necessarily occur every time the person eats red meat.
  • The immune system of people with an alpha-gal allergy treats the alpha-gal molecule in meat as a physical threat to the body. Histamine and other chemicals are released to try to “protect” the person, and these cause an allergic reaction.


  • Many people who acquire an alpha-gal allergy have no history of other allergies or allergic symptoms.However, discovering whether the person has had a tick bite in the preceding weeks or months will help a doctor make a diagnosis.
  • Characteristics of red meat allergies differ from other allergies, as people do not usually experience symptoms until at least 2 hours after eating red meat. This delay can help doctors diagnose an alpha-gal allergy.
  • However, as the connection between the symptoms and the consumption of red meat is not always clear, often it takes an allergist with expert knowledge of the condition to diagnose it.
  • A blood test will identify whether alpha-gal antibodies are present in an individual’s bloodstream. Results usually take 1 to 2 weeks.
  • A skin test can also be done, which involves a small amount of the food allergen pricked onto the skin.
  • If a wheal (a bump similar to a mosquito bite) develops, then it is a positive result. The test takes about 20 minutes and can be uncomfortable, but not usually painful.


  • All mammal meats should be avoided.
  • A person diagnosed with an alpha-gal allergy will probably have to change their diet and be careful when they eat out. Seafood, poultry, and eggs are acceptable protein choices for those with alpha-gal allergies. Many people can also tolerate dairy products.
  • How cautious a person needs to be will depend on how severe their symptoms are.  For example, some people experience a reaction if their food was prepared in the same kitchen as red meat.
  • In serious cases they might be prescribed with epinephrine in the form of an autoinjector


  • The best way to avoid contracting an alpha-gal allergy is to avoid getting bitten by ticks.
  • If people live in an area where Lone Star ticks are prevalent, there are ways to avoid getting bitten. These include:
  1. avoiding wooded, overgrown areas, or high grass where ticks live
  2. wearing light-colored clothing that fully covers the limbs when hiking or camping
  3. checking pets and livestock for ticks regularly
  4. using insect repellent
  5. washing clothing in hot water after returning from a wooded area
  • There is some evidence that a person may recover from alpha-gal allergy if they are not re-infected by another tick bite.


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