Alpha-gal syndrome (AGS), also known as mammalian meat allergy, is an IgE antibody response to the disaccharide galactose-α-1,3-galactose (α-Gal). This sugar, commonly known as alpha-gal, is found in all mammals except for certain monkeys, apes, and humans, as well as some other organisms. The onset of AGS is associated with tick bites (1).
Not only is alpha-gal found in mammal products such as beef, pork, lamb, organs, blood, lard, flounder eggs, milk, and dairy, however it is also in gelatin, certain medications, vaccines, medical products (heparin and vaccines), personal care products (lotion and make-up), and many other items. (2)
Reactions to alpha-gal are often severe and, in some cases, fatal. They can be immediate or delayed by 2 to 10 hours or more.
Alpha-gal Syndrome Prevalence in the US
In the U.S., lone star tick bites (sometimes called the meat allergy tick) are believed to be the leading source of sensitization (3). However, there are other ticks in other locations of the world that are thought to cause alpha-gal syndrome as well.
- Alpha-gal syndrome is found on every continent except Antarctica.
- In the U.S., alpha-gal syndrome is mostly found in areas where the Lone Star Tick lives, including the southeastern United States, all along the East Coast, and in the Midwest.
- It has been reported that the Lone Star Tick populations are growing, creating a rise in alpha-gal syndrome
This map includes self-reported cases to give you an idea of distribution of alpha-gal syndrome in the United States. There are pins included in other parts of the world as well. However, far fewer cases have been reported for other countries.
Diagnosing Alpha-Gal Syndrome
A number of tests and taking a clinical history can be helpful in the diagnosis of alpha-gal syndrome.
Clinical history includes questions regarding:
- History of allergic reactions to mammalian meat, regarding symptoms, timing of symptoms, and age of onset
- History of exposure to ticks
- Responsiveness to dietary changes
- A blood test for Galactose-alpha-1,3-galactose (alpha-gal) specific IgE (sIgE) 1,2).
- In the U.S., this test is available via Viracor Eurofins Clinical Diagnostics. In Europe, it is available via Phadia Thermofisher.
- There are some physicians that are set up for their patients to be tested with Viracor. However, it is common to send patients to a commercial lab, such as Quest or Labcorp, which send samples to Viracor to be tested with the correct codes.
Skin prick tests may also be done. Although, they are often unreliable and not recommended for the diagnosis of alpha-gal syndrome.
Based on leading export, Scott Commins’s MD, PhD experience in research with over 2,500 patients, “In >90% of cases, the diagnosis of AGS can be made based on a history of delayed allergic reactions after eating non-primate mammalian meat (e.g. ‘red meat’ such as beef, pork, or lamb) and a positive blood test (>0.1 IU/mL) for IgE to alpha-gal. The combination of both an appropriate clinical history and supporting blood test is necessary to establish an accurate AGS diagnosis (2).”
Alpha-Gal Syndrome Symptoms
- Itching of the palms and soles of feet
- Urticaria (hives)
- Specifically, the palms and soles of the feet
- Abdominal pain and cramping
- Nausea and vomiting
- Hypotension (low blood pressure
- A weak and rapid pulse
- Pre-syncope (feeling like you may pass out)
- Syncope (fainting, loss of consciousness)
- Shortness of breath
- Chest tightness (
- Dyspnea (difficulty breathing)1
At this time there is not a cure for AGS. Part of the treatment includes dietary restrictions of foods and other products that contain alpha-gal in order to prevent allergic reactions. Food avoidance can be quite individualized depending on the tolerance levels of each person.
Making sure that you have antihistamines, or an epinephrine autoinjector, or an EpiPen is also recommended.
Avoidance of additional tick bites is necessary as well. Another tick bite can make AGS allergic reactions worse, specifically from a Lone Star Tick.
While there is no guarantee, it has been noted that with time reactions may become less severe or people can even go into remission.
Support for AGS
Connecting with others battling alpha-gal syndrome can be helpful in understanding certain foods, products, and medical supplies that would contain this sugar, that one normally wouldn’t think of. Sharing recipes that do not contain alpha-gal can also be informative in broadening your dietary options. At The Lyme Specialist through our Nutrition Practice, we can also help you navigate the healthy and safe dietary options.
Below are links with information for support:
I have also found @twoalphgals to be a wealth of knowledge when trying to navigate this condition.
As the rise is alpha-gal syndrome increases, it is still a very unknown condition. This is an issue, as the effects of this condition can be immediate and severe. Creating more awareness around AGS will hopefully help people suffering to understand the proper treatments to help them on the path of moving forward.
- Commins SP. Diagnosis & management of alpha-gal syndrome: lessons from 2,500 patients. Expert Rev Clin Immunol. 2020 Jul;16(7):667-677. doi: 10.1080/1744666X.2020.1782745. Epub 2020 Jul 8. PMID: 32571129; PMCID: PMC8344025.
- Commins SP, James HR, Kelly LA, Pochan SL, Workman LJ, Perzanowski MS, Kocan KM, Fahy JV, Nganga LW, Ronmark E, Cooper PJ, Platts-Mills TA. 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):1286-93.e6. doi: 10.1016/j.jaci.2011.02.019. Epub 2011 Mar 31. PMID: 21453959; PMCID: PMC3085643.