Diagnosis and Testing

How Is Alpha-gal Diagnosed?

If you experience symptoms after eating mammalian meat, your primary care physician or allergist should be able to determine whether you have alpha-gal syndrome, pork-cat syndrome, an allergy to meat proteins, or a different health issue.

Doctors diagnose alpha-gal syndrome through a combination of clinical history and blood tests, including:

  • History of allergic reactions to mammalian meat, including symptoms, timing of symptoms, and age of onset
  • Past exposure to ticks
  • A blood test for Galactose-alpha-1,3-galactose sIgE, often as part of a panel of tests, called an Alpha-gal Panel
  • Responsiveness to dietary changes

Prick test with extracts of beef or pork are unreliable and not recommended. (1)(2)

Intradermal tests can be used in the diagnostic process, but few clinics use them. (1)(2)

Occasionally, food challenges are used in diagnosis of AGS, especially when blood tests are negative but there is a history of delayed reactions after ingestion of mammalian meat. Food challenges need to be conducted with the utmost care, both because of the delayed nature of AGS reactions and because over 60% of people with AGS have anaphylactic reactions. 

 

My allergist ordered the right test for the allergy to Alpha-gal, but the lab tech in the hospital couldn’t find a code for it, so when the test came back positive, the lab tech coded me positive for Fabry disease.

—Bethany Welch

It took 2 weeks to get diagnosed. My doctor told me there was no way I had alpha-gal syndrome, and said he was only running the test to prove me wrong.

---Amber Roberts

What Blood Tests Do Doctors Use to Help Them Diagnose Alpha-gal Syndrome?

  • The set of blood tests that doctors usually use to help them diagnose alpha-gal syndrome is called an Alpha-gal Panel.
  • Total IgE should also be measured, as some cases are non-atopic and have low total IgE and the ratio of alpha-gal IgE to total IgE is clinically significant.(1)
  • In the U.S., Viracor Eurofins Clinical Diagnostics is the main lab that does this test. See the websites and information below:
    • Alpha-Gal Panel
      Test Code: 403196P
      Tests in this Panel
      Galactose-alpha-1,3 galactose (Alpha-Gal) IgE
      Beef (Bos spp) IgE
      Pork (Sus spp) IgE
      Lamb / Mutton (Ovis spp) IgE
  • Both Quest and Labcorp can send your blood samples to Viracor, if your doctor gives them the right codes, which you can find on the links below:
  • Unfortunately, in many cases, the wrong blood test is performed. The test below is NOT the right test for diagnosing alpha-gal syndrome. It’s for diagnosing another condition, Fabry disease.
    • α-Galactosidase A Deficiency  This is the wrong test!
  • Sometimes doctors order the test for alpha-gal IgE alone, not the whole panel. When they do this, they usually order tests for beef and pork IgE, and sometimes milk IgE, as well. This helps them figure out if you have another condition, like pork-cat syndrome, or an allergy to proteins in beef, pork, or milk. See links below for lab codes for alpha-gal IgE alone:
  • Ask your doctor for a copy of your lab report, both for your records and so you can make sure the right test was ordered.

Talking to Your Doctor about Alpha-gal Syndrome

Since alpha-gal syndrome was only recently discovered, and knowledge about it is evolving rapidly, your doctor might not have heard of AGS or might have misconceptions about it.  It may help your doctor if you bring the following to your appointment:

  • Notes about any exposure to ticks
  • Notes about your symptoms, when they occurred and what foods you ate prior to the onset of symptoms
  • Information about alpha-gal syndrome, such as Diagnosis and management of patients with the α-Gal syndrome. Currently, the full text is not available online. You can buy the PDF, ask your local librarian for help accessing it, or just bring a copy of the abstract. Your doctor should be able to access the full text.
  • Information about the Alpha-gal Panel blood test

Ask your doctor if they have access to Up-to-Date. If they do, recommend that they read the article on meat allergies, which is written by Scott P. Commins, MD, PhD, a leading expert on AGS.

Learn More about What Your Test Results Mean

Go to What Do My Test Results Mean?

References

1. Platts-Mills, T. A., et al. (2019). “Diagnosis and management of patients with the alpha-Gal syndrome.” J Allergy Clin Immunol Pract.

2. Commins, S. P., et al. (2009). “Delayed anaphylaxis, angioedema, or urticaria after consumption of red meat in patients with IgE antibodies specific for galactose-α-1,3-galactose.” Journal of Allergy and Clinical Immunology 123(2): 426-433.e422.