| | | Some background on the syndrome Lee mentioned...
Alpha-gal allergy
en.wikipedia.org
Alpha-gal allergy — or mammalian meat allergy (MMA) [1] — is a type of meat allergy characterized by a delayed onset of symptoms (3–8 hours) after ingesting mammalian meat and resulting from past exposure to tick bites. It was first reported in 2002. Symptoms of the allergy include rash, hives, nausea or vomiting, difficulty breathing, drop in blood pressure, dizziness or faintness and severe stomach pain. [2]
Alpha-gal allergy is a reaction to galactose-alpha-1,3-galactose ("alpha-gal"), whereby the body is overloaded with immunoglobulin E (IgE) antibodies on contact with the carbohydrate. [3] Anti-gal is a human natural antibody that interacts specifically with the mammalian carbohydrate structure gal alpha 1-3Gal beta 1-4GlcNAc-R, termed, the alpha-galactosyl epitope. [4] The alpha-gal molecule is found in all mammals except Catarrhines ( apes and Old World monkeys). [4]
Bites from certain ticks, such as the lone star tick ( Amblyomma americanum) in the US, and the paralysis tick ( Ixodes holocyclus) in Australia, which can transfer this carbohydrate to a victim, have been implicated in the development of this delayed allergic response to consumption of mammalian meat products. [5] Individuals with alpha-gal allergy do not need to become strict vegetarians, because poultry, fish, and in rare cases for some people, lean meat such as venison does not trigger a reaction. [6]
Alpha-gal allergy has been reported in 17 countries on all 6 continents where humans are bitten by ticks, particularly the United States and Australia. [7] As of November 2019 Australia has the highest rate of mammalian meat allergy and tick anaphylaxis in the world. [8] In the US, the allergy most often occurs in the central and southern regions, which corresponds to the distribution of the lone star tick. [9] In the Southern United States, where the tick is most prevalent, allergy rates are 32% higher than elsewhere. [10] However, as doctors are not required to report the number of patients with alpha-gal allergy, the true number of affected individuals is unknown. [11] Alpha-gal has also been shown to exist in the saliva of Ixodes scapularis but not Amblyomma maculatum. [12]
Alpha-gal allergies are the first known food allergies that present the possibility of delayed anaphylaxis. [13] [14] [15] It is also the first known food-related allergy associated with a carbohydrate, rather than a protein. [14] [16] Other mammalian products containing alpha-gal other than meat such as milk and gelatin may also trigger an allergic reaction. [17]
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