Alpha-Gal syndrome, also known as a delayed mammalian (red) meat allergy (and sometimes mistakenly referred to as “alpha-Gal allergy”), is a tick-related allergic reaction to a sugar found in red meats, including beef, pork, venison, and lamb.1,2 In the United States, alpha-Gal syndrome has been primarily connected to a bite from the Lone Star tick (Amblyomma americanum).3,4 This is how it works: First, a bite from a tick can potentially transfer alpha-Gal into a person’s bloodstream. In some of the children and adults bitten, that transfer can cause a production of specific IgE which in turn can cause a delayed allergic reaction after they eat red meat. This means an alpha-Gal reaction can appear suddenly in people who have happily eaten meat for years.5
Adapted from Steinke JW, Platts-Mills TA, Commins SP. The alpha-gal story: lessons learned from connecting the dots. J Allergy Clin Immunol. 2015;135(3):589‐597. doi:10.1016/j.jaci.2014.12.1947
Unlike most food allergies, where symptoms often appear within minutes, symptoms of alpha-Gal syndrome are typically delayed by three to six hours or more.6,7 This delay contributes to confusion, as people suffering from the syndrome struggle to connect their reaction to meat consumed hours before. A convenient blood test that measures these antibodies can help your healthcare provider determine if you have alpha-Gal syndrome.
Symptoms can appear 3 to 6 hours or more after the consumption of red meat.6,7
Common alpha-Gal symptoms include:
It’s important to note that things such as non-steroidal anti-inflammatory drugs (NSAIDs), exercise, alcohol, and recent tick bites may increase the risk or severity of reaction.2,10
Alpha-Gal allergy symptoms can vary from person to person, but most reactions are skin or stomach-related. Reactions can also range from mild to severe, including the life-threatening reaction, anaphylaxis.1,8,9
The first step to determine the cause of a reaction is to identify allergic triggers. This is especially important because while they are undiagnosed, people with alpha-Gal syndrome are likely to make many trips to the emergency room and visits to their healthcare provider, searching for answers they don’t always get.11 In fact, one study found that almost 80 percent of patients with alpha-Gal syndrome weren’t diagnosed for more than seven years.11
Because alpha-Gal syndrome symptoms may be delayed by hours, it can be hard to associate the symptoms with eating red meat or a product made with mammalian meat (such as gelatin) hours earlier, not to mention relating it to a tick bite in the past. Since this syndrome was only first reported in the late 2000s, many people are unaware of it—including healthcare providers. This has led people to self-diagnosis, but if you think you or a loved one has an alpha-Gal allergy, don’t try to manage the problem on your own.11
So what are your testing options? Your allergist cannot perform skin-prick tests (SPT) directly for alpha-Gal sensitization, making specific IgE blood testing for the alpha-Gal component the preferred diagnostic method.12
A convenient blood test that any provider can order—together with your medical history—can help identify underlying allergic triggers, if you have an allergy. Knowing if you’re allergic and what you’re allergic to may also help you avoid more serious issues in the future. Be sure to consult with your healthcare provider to get detailed answers to your alpha-Gal questions. Because it’s not just knowledge you’ll gain, but peace of mind, too.
The primary advice after an alpha-Gal allergy diagnosis is that all mammalian (red) meats and red meat by-products should be avoided.9 The most common triggers are beef, pork, lamb, but also includes red meats like horse, goat, rabbit, squirrel and venison, plus organ meats.2,17 Some people may also need to avoid dairy products, including milk and cheese, and gelatin-containing foods like marshmallows and jelly candies.2,9 Mammalian by-products including alpha-Gal can also be found in medications, cosmetics, and vaccines which can also cause a reaction.2, 14-17
Not all triggers are equally likely to cause a reaction—see the chart for triggers ranked from higher to lower risk.2
What can your My Symptom Profile tell you about allergies? Nothing, by itself. So resist the temptation to self-diagnose. Treating allergy symptoms with over-the-counter medications or other remedies without determining the cause could lead to more issues in the long run. When paired with testing, such as specific IgE blood testing for food or respiratory allergies, your My Symptom Profile can guide your healthcare provider in creating a customized trigger-management plan to help reduce exposure to suspected allergens.
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What to know about specific IgE blood testing
What to know about specific IgE blood testing
What to know about specific IgE blood testing
What to know about specific IgE blood testing