Today’s Dietitian
Vol. 28 No. 2 P. 40
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Alpha-gal syndrome (AGS) is an allergic condition that can develop after the bite of a tick. The condition involves a hypersensitivity response to an oligosaccharide, galactose-alpha-1,3-galactose, or commonly called alpha-gal.1 The alpha-gal molecule is found in the tissues of all nonprimate mammals.2 AGS is commonly referred to as a red meat allergy, but the allergic reaction can occur with any food or product containing alpha-gal.
History and Prevalence
AGS was discovered in the early 2000s during clinical trials for the cancer drug cetuximab.3 Cetuximab contains alpha-gal epitopes.4 Hypersensitivity reactions to cetuximab occurred rapidly during the first infusion of the medication. Reactions ranged in severity from urticaria to anaphylaxis, which was, in some cases, fatal.3,4 The severe hypersensitivity reactions seen with cetuximab were predominantly occurring in a group of southeastern US states, suggesting an environmental factor at play.3 This region was common for Rocky Mountain Spotted Fever, a tickborne disease.4 Increasing reports of allergies to red meat were also occurring in this region.4 Investigations into these reactions showed that the affected patients had immunoglobulin E (IgE) specific antibodies against the alpha-gal molecule, which were present before administration of cetuximab.
AGS is primarily associated with the lone star tick (amblyomma americanum), which is mainly found in the southeastern parts of the United States.5,6 However, AGS cases are being reported in northern and western areas of the United States due to climate change and the growing, migrating population of white-tailed deer, the lone star tick’s primary host.4,5 The increasingly hospitable conditions contribute to the growing worldwide presence of AGS, ranging from Central and South America to Europe, Asia, Africa, and Australia.4,5,7
More than 110,000 suspected cases of AGS were identified in the United States between 2010 and 2022.1 However, the actual number of people with AGS may be much higher due to several factors. Many AGS cases go undiagnosed due to low health care provider awareness of AGS and lack of confidence in diagnosing or managing the condition.8 Many individuals with AGS experience only gastrointestinal (GI) symptoms which mimic those of irritable bowel syndrome (IBS), leading to a misdiagnosis of IBS.9 AGS is also not a nationally notifiable condition, but some states may require reporting.10 Addressing these barriers can provide better understanding of national trends.
Transmission and Risk Factors
Lone star ticks can have alpha-gal in their saliva and digestive tract after feeding on a nonprimate mammal. Some evidence also suggests that the alpha-gal in the tick’s saliva is present endogenously or passed through the life stages.4 When the tick then bites a human, alpha-gal is injected into the bloodstream, activating the immune system, and leading to the development of IgE antibodies against alpha-gal.4 After this sensitization occurs and AGS develops, ingestion of red meat or other foods or products containing alpha-gal trigger a hypersensitivity reaction of varying degrees.4
Not all people who are bitten by a lone star tick or become sensitized to alpha-gal develop AGS.11 People who spend a lot of time outdoors, live in or visit areas with large tick populations, and have received multiple lone star tick bites are at an increased risk of AGS.5 Other risk factors have also been associated with an increased risk of AGS.
Non-B Blood Type
Most people with AGS have non-B blood types (A, O).12,13 B or AB blood types seem protective against AGS.14,15 The alpha-gal molecule is structurally similar to the B blood group.12 It is hypothesized that this similarity can influence sensitization to and tolerance of alpha-gal.13
Age
Although AGS occurs mostly in adults, children are also susceptible.16 Studies show a 13% to 35% lower incidence of AGS in children compared with adults.12,17,18 However, this may simply be due to adults having increased outdoor activity and higher chances of environmental exposure compared with children. Children also present with a predominance of GI symptoms but a restricted number of trigger foods compared with adults.12
An important study by Vanderbilt University Medical Center looked at 199 children with suspected AGS.19,20 Forty patients tested positive for alpha-gal-specific IgE, and about 30 presented with only GI-related symptoms.19,20 Dietary elimination of red meat, dairy, and gelatin resulted in significant symptom improvement for eight of the patients and complete symptom disappearance in another eight patients.19,20
Allergic Cofactors
Allergic cofactors can affect how the body responds to an allergen, increasing the severity of the reaction or lowering the threshold of the allergen needed to trigger a reaction. Examples of allergic cofactors include exercise, certain medications (such as NSAIDs), alcohol, sleep deprivation, and infection.12,21,22 Exercise and alcohol were identified as primary cofactors for alpha-gal reactions.16,21 In children, exercise showed a strong association with reactions.21
Atopy
Atopy is a genetic predisposition to developing allergic reactions, particularly to environmental allergens, such as asthma, allergic rhinitis, and atopic dermatitis.23 People with atopy tend to produce higher levels of IgE antibodies in response to environmental allergens and food allergens. However, the association between atopy and AGS needs further clarification.12
Length of Exposure
Length of the tick feeding may also increase AGS risk, according to one AGS expert.24 Characteristic cutaneous reactions to tick bites include redness, warmth, itchiness, swelling, and even a rash at the bite site. However, some people experience none of these symptoms. Prompt removal of ticks is always advised, as typically, the longer they stay attached, the greater the risk of disease transmission. However, since alpha-gal is not a bacterial transmission, being at risk of AGS as soon as the tick bite occurs has not been ruled out. Therefore, it is best to avoid tick bites in the first place.
Other Vectors
Recent cases located well outside the geographic areas of the lone star tick have connected AGS with two other tick species in the United States—the western blacklegged tick (Ixodes pacificus) and the blacklegged or deer tick (Ixodes scapularis).6,25 Alpha-gal has also been found in numerous other tick species, further expanding the possible culprits of AGS.5,7,24-26 Worldwide, several other tick species are suspected of being associated with AGS.24
Reports have also connected AGS with bites from chiggers, which are microscopic mite larvae.27,28 However, bites from chiggers can often be confused with bites from seed ticks, which are the larvae of ticks.28 Seed ticks, though very small, can still transmit alpha-gal.27 Preliminary data suggests that parasitic worms (Ascaris lumbricoides) and fleas may be associated with AGS.24,29 More data is needed to determine which tick species and other invertebrates are primary vectors of AGS.
Sources of Alpha-Gal
The alpha-gal oligosaccharide is found in all nonprimate mammals and products derived from those mammals.2 Foods containing alpha-gal include red meat such as beef, pork, lamb, goat, rabbit, and wild game (such as venison, buffalo, bison, and elk).16,30,31 Organ meats from mammals (such as liver, kidneys, intestines, tripe, sweetbreads) and dishes made from these items should also be avoided.16,30,31 Food additives or products made with alpha-gal sources include whey protein, lard, tallow, gelatin, collagen, or broths, bouillons, stocks, and gravies made from mammalian meat.16,30,31 Some less obvious gelatin-containing products include certain gummy candies and marshmallows.
Dairy products, such as milk, cheese, yogurt, butter, and ice cream, contain alpha-gal but at lower levels than meat.30 Although some people with AGS can tolerate dairy products, an estimated 5% to 20% of people with AGS will experience allergic reactions to them.30
Although reactions are less common, many medications and personal care products include materials derived from mammals and may also need to be avoided.30 Examples are cetuximab, thyroid hormone supplements, snake antivenom therapy, heparin, pancreatic enzymes, magnesium stearate, vaccines containing gelatin, gel capsules, and prosthetic heart valves from pigs or cows.16,30,31
Some individuals with AGS report reactions to airborne alpha-gal exposure, such as fumes from cooking meat or dairy products.32 Inhalation of powdered dairy products, dander from livestock or mammalian pets, and air fresheners containing carrageenan are other potential airborne sources.32 More research is needed to examine the connection between AGS and airborne exposure.
Foods and products that should be avoided will be determined individually.4 People with AGS should consult with their health care provider or care team about which foods or other products they should avoid. Meats and animal products that do not contain alpha-gal are safe for people with AGS to consume. This includes chicken, turkey, duck, quail, fish, shellfish, and eggs.31
Symptoms
AGS can be simply defined as a type of food allergy. However, unlike typical food allergies, which result in an immediate reaction within minutes of exposure, AGS involves a significant time delay between exposure to alpha-gal and the allergic reaction.5,16 Symptoms of AGS usually occur anywhere from two to six hours after eating meat or dairy and often occur late in the evening or in the middle of the night, making the connection between triggers and hypersensitivity events easier to overlook.4,5,16 It is hypothesized that the delayed reaction may be due to the body taking longer to digest carbohydrates, like the alpha-gal antigen, vs proteins (the triggers for most other food allergies).5,16
Specific symptoms and their level of severity can differ greatly among people with AGS.26 Some people may only experience one symptom, but most report multiple symptoms.4
About 90% of AGS reactions involve the skin.21 Skin reactions include hives (urticaria), itching (pruritis), flushing (erythema), and swelling of the face, lips, tongue, or throat (angioedema).16,30 Itching on palms of the hands and soles of the feet is often the first symptom of AGS.21
Over 60% of AGS reactions involve GI issues such as stomach pain, nausea or vomiting, diarrhea, constipation, heartburn, or indigestion.16,19,21,30 Up to 20% of people experience only GI issues, often leading to a misdiagnosis of IBS.21
About 30% to 40% of AGS reactions involve cardiac symptoms such as a decrease in blood pressure (hypotension), dizziness, and heart palpitations.16,21,30 Three to five percent report mast cell activation syndrome.16,21,30 Respiratory symptoms of AGS include shortness of breath, wheezing, cough, difficulty breathing, and, in some cases, anaphylaxis.16,30
Complications
Like other food allergies, people with AGS who do not adhere to their dietary or product/lifestyle restrictions or who don’t treat allergic reactions when they happen may experience serious, even life-threatening, complications. Probably the most notable of these reactions is anaphylaxis. This serious allergic reaction involves the body’s respiratory and circulatory systems.33 Signs of anaphylaxis include a tight, narrow airway; throat swelling, which limits or prevents breathing; rapid pulse; feeling of dizziness or lightheadedness (sometimes passing out); and a significant drop in blood pressure, known as shock. Anaphylaxis requires immediate treatment with a prescription medication called epinephrine.
About 60% of AGS cases report anaphylaxis.21 A recent study found that AGS was the number one trigger for anaphylaxis, accounting for 33% of cases.34 Recognition of AGS led to reduced incidence of anaphylaxis. Given the rising incidence of AGS, people who experience recurrent anaphylaxis of unknown origin should consider being tested for AGS, especially if they live in areas with high tick populations or present with new-onset skin or GI symptoms.
Diagnosis
Diagnosing alpha-gal involves a personal and medical history review, physical examination, and diagnostic tests. A physician or allergist will inquire about the type and frequency of symptoms, history of tick bites and any cutaneous reactions that occurred at the bite site, and risk of AGS based on location of residence and exposure to likely tick habitats. A physical exam may evaluate skin, blood pressure, and lungs. For some, observed challenges may be performed in the hospital setting to prove AGS if experiencing GI-related reactions.19
The main confirmatory, diagnostic method of AGS involves blood testing to check for the presence of alpha-gal-specific IgE antibodies in the bloodstream.10,16 While some health care providers still use skin-prick tests to check for reactions to beef and pork, these tests have been unreliable in detecting alpha-gal and are generally not recommended.4,10,35
Treatment and Prognosis
There is currently no cure for AGS.16 Treatment involves avoiding foods and products with alpha-gal. Preventing additional tick bites is also crucial, as this can reactivate and increase the severity of the allergy.19 Medications such as antihistamines, epinephrine, or oral cromolyn sodium may be prescribed to help manage symptoms.16
Members of an AGS treatment team often include a skilled physician or allergist but may also include specialists as needed, based on symptom categories—dermatologists, gastroenterologists, pulmonologists, or cardiologists.16 Emergency department care teams may be needed to help manage severe reactions, such as those involving anaphylaxis.5 Dietitians are also an important part of the care team due to their extensive knowledge of foods, supplements, ingredient labels, and more.16 Dietitians can assist with maintaining a healthy diet that prevents or minimizes nutrient deficiencies while avoiding alpha-gal food sources.
For many, AGS is a lifelong condition. For others, AGS symptoms lessen or even fully resolve over time.5 Blood tests can be performed every few months to see if alpha-gal-specific IgE antibody levels are decreasing.5,25 For some, alpha-gal may be reintroduced into the diet after one to two years.5
Dietary Patterns
Due to individual levels of sensitivity to alpha-gal and different trigger foods or products, a dietary pattern (as opposed to a prescribed diet plan) may not be appropriate for everyone with AGS. However, certain dietary patterns may prove effective for some in managing their AGS. Individuals with AGS should collaborate with a dietitian or other qualified health care professional to determine the diet plan or pattern most suited to their needs.
Vegan Diet
A vegan diet, which excludes all animal-derived products, can be appropriate for those with high sensitivity to alpha-gal who are unable to tolerate red meat, dairy products, and other animal-based items such as gelatin. The vegan dietary pattern has shown numerous health benefits regarding lowering LDL cholesterol, improving blood pressure, and managing blood glucose.36 While plant-based foods such as legumes, nuts, seeds, and tofu can help ensure adequate protein consumption, certain nutrients may be difficult to obtain in adequate amounts. Dietitians or other appropriate health care professionals should counsel clients on optimal dietary practices or supplements to ensure adequate consumption of protein, calcium, iron, omega-3 fatty acids, vitamin B12, and zinc.36,37
Vegetarian Diet
A vegetarian diet is more liberal compared with a vegan diet and may be adjusted to individual preferences and tolerances. A lacto-vegetarian diet includes dairy products and would likely be appropriate for individuals with lower sensitivities to alpha-gal who do not experience allergic reactions to dairy products. A lacto-ovovegetarian diet includes dairy products and eggs. Since eggs are nonmammalian food, they are safe for people with AGS if the eggs have not been processed with or cross-contaminated by products containing alpha-gal. A pescatarian diet, while not always considered a vegetarian diet, includes fish, seafood, eggs, and dairy products.38 Fish and seafood do not naturally contain alpha-gal. Compared with a vegan diet, risk of nutrient deficiency is lower when following a well-balanced vegetarian diet.38
Mediterranean, DASH, and Flexitarian Diets
Other plant-based dietary patterns may be suitable for those with AGS. The Mediterranean diet primarily includes fruits, vegetables, whole grains, beans, lentils, nuts and seeds, extra virgin olive oil, and fish.39 The dietary pattern limits cheese and yogurt to moderate amounts and recommends avoiding or significantly limiting red meat. The DASH diet includes poultry, fish, and a variety of plant-based foods but limits saturated fats such as those found in red meats and full-fat dairy products.40 The flexitarian dietary pattern involves following vegetarian diet recommendations most of the time with the occasional inclusion of meat in the diet.41 Dairy products in both the Mediterranean diet and the DASH diet may be excluded for those with AGS who experience allergic reactions to them. Red meat should be avoided by those with AGS in all dietary patterns.
A Note on Carrageenan
One to two percent of people with AGS will experience an allergic reaction to carrageenan.11,16 Although carrageenan is not an animal product, it does contain alpha-gal epitopes. Carrageenan is a vegan food additive found in many different products, including those popular in vegan or other plant-based diets.16,42 It is used as a stabilizer in almond milk and other plant-based milk substitutes.43 It is often used in place of gelatin or animal fats to allow foods to meet vegan standards.43 It can help food retain moisture and freshness and retain taste quality.43 When used as a processing agent rather than a food additive or ingredient, carrageenan is not required to be listed on the food label.42 It is important for those with AGS who are sensitive to carrageenan to be aware of which foods contain, or may have been processed with, carrageenan.
Prevention
Avoiding tick bites is the best way to prevent AGS and other tickborne illnesses. Avoid or limit time in wooded, bushy areas with tall grass where ticks are commonly found.44 Clear away brush and leaf litter in yards.5,44 Wear long clothing (light-colored, if possible, to aid in visibility of ticks) and consider tucking pants into socks.5,6,44
Insect repellent is another tick-preventing option but must be used carefully.
Permethrin is an insecticide and insect repellent that is applied to clothing or outdoor gear, not on skin.45 Treated clothes and gear will remain repellent to insects for approximately two weeks to up to six months.45 Permethrin may cause mild skin irritation for some people but otherwise has a low toxicity to people.45
Applying an insect repellent with DEET (N, N-Diethyl-meta-toluamide or diethyltoluamide) or picaridin to the skin in combination with applying permethrin to clothing and gear can provide even greater protection against ticks. Effective and typically recommended concentrations of DEET range from 20% to 30%.46 Because DEET is absorbed by skin, application instructions should be followed carefully, especially when applying it to children.45 Picaridin is another safe, effective repellent option that is applied to the skin. Although like DEET, picaridin is also absorbed through the skin, it is odorless, nongreasy, and less likely to cause skin irritation.45
After being outdoors, check yourself, your children, and your pets for ticks. Ensure you check your entire body. Commonly overlooked areas include the scalp, behind the knees, and the belly button.44 Showering as soon as you come indoors can help remove unattached ticks, as ticks often latch onto skin for a few hours before biting.45 If you do find a tick that has bitten you, remove it as soon as possible. Using tweezers, gently grab the tick near its head or mouth, being careful not to squeeze or crush it.45,47 Dispose of the tick by placing it in a sealed container, flushing it down the toilet, or submerging it in alcohol.47 Clean the bite area with antiseptic or soap and water.47
Emerging Research
The FDA has approved a new breed of pigs which were genomically altered to eliminate alpha-gal on the surface of the pigs’ cells.48 Although these pigs will be kept under much more stringent conditions than conventionally farmed pigs, they can be raised and sold by farmers as alpha-gal-free pork. This is great news for those affected by AGS, as they may be able to safely eat pork products harvested from these GalSafe pigs.48
The biomedical potential of GalSafe pigs is also notable. These pigs can be used to make a wide variety of products safe for those with AGS, such as gelatin, medications, and more. The GalSafe pigs also provide much hope for the future of xenotransplantation.3,13,48 All nonimmunocompromised humans have antibodies against alpha-gal found on nonprimate mammalian red blood cells.3,13 These antibodies play a role in immune rejection, creating a significant barrier between organ and tissue transplants from animals to humans.3,13 The GalSafe pigs offer potential for major medical milestones and scientific innovations.
Areas for Improvement
There is still much to learn when it comes to AGS. Despite the rapidly rising number of cases, AGS is still relatively unknown to many health care providers.49 In 2023, a national survey revealed that as many as 42% of health care providers had no awareness of AGS.8 Of those who were aware, about 33% did not know how it was acquired and about 50% did not know what tests to use to diagnose it.8 The gaps in health care provider knowledge can hinder proper and timely diagnosis.8 One study showed that almost 80% of patients with AGS spent more than seven years struggling to find a diagnosis with many undergoing invasive GI surgery in an effort to resolve their symptoms of unknown origin.49
Targeted public health outreach to increase awareness of AGS and educate on avoiding tick bites can also help with preventing AGS in high-risk areas.8,26 Educating health care providers on the best diagnostic methods and management strategies for AGS can significantly improve patient outcomes and quality of life.8,26,49
Putting It Into Practice
Dietary interventions remain the primary method of treatment for AGS. Identifying individual triggers and levels of sensitivity to alpha-gal is the primary strategy for managing AGS. Dietitians can provide advice on which foods and other products to avoid, tailoring these dietary recommendations to accommodate the food preferences of each client. For those experiencing allergic reactions to dairy products, alternative sources of calcium and vitamin D may need to be incorporated into the diet to prevent nutrient deficiencies. Dietitians can also provide guidance on other protein options that can safely be consumed. If blood levels of IgE antibodies indicate safety to resume consumption of alpha-gal, dietitians can design a plan to slowly incorporate these previous trigger foods back into the client’s regular diet.
— Natalie Sexton, MS, RDN, CSR, LD, is a registered dietitian, health coach, and freelance writer based in the northeast Texas area.
References
1. About alpha-gal syndrome. US Centers for Disease Control and Prevention website. https://www.cdc.gov/alpha-gal-syndrome/about/index.html. Updated June 26, 2025. Accessed February 23, 2025.
2. Platts-Mills TAE, Cummins SP, Biedermann T, et al. On the cause and consequences of IgE to galactose-α-1,3-galactose: a report from the National Institute of Allergy and Infectious Diseases Workshop on understanding IgE-mediated mammalian meat allergy. J Allergy Clin Immunol. 2020;145(4):1061-1071.
3. Steinke JW, Platts-Mills TA, Commins SP. The alpha-gal story: lessons learned from connecting the dots. J Allergy Clin Immunol. 2015;135(3):589-596.
4. Houchens N, Hartley S, Commins SP, Claar D, Saint S. Hunting for a diagnosis. N Engl J Med. 2021;384(5):462-467.
5. Alpha-gal syndrome. Mayo Clinic website. https://www.mayoclinic.org/diseases-conditions/alpha-gal-syndrome/symptoms-causes/syc-20428608. Updated August 8, 2025. Accessed February 23, 2025.
6. Guide to different tick species and the diseases they carry. Mayo Clinic website. https://www.mayoclinic.org/diseases-conditions/alpha-gal-syndrome/in-depth/tick-species/art-20546861. Updated November 14, 2023. Accessed April 27, 2025.
7. Kwak M, Somerville C, van Nunen S. A novel Australian tick Ixodes (Endopalpiger) australiensis inducing mammalian meat allergy after tick bite. Asia Pac Allergy. 2018;8(3):e31.
8. Carpenter A, Drexler NA, McCormick DW, et al. Health care provider knowledge regarding alpha-gal syndrome — United States, March-May 2022. MMWR Morb Mortal Wkly Rep. 2023;72(30):809-814.
9. Croglio MP, Commins SP, McGill SK. Isolated gastrointestinal alpha-gal meat allergy is a cause for gastrointestinal distress without anaphylaxis. Gastroenterology. 2021;160(6):2178-2180.
10. Alpha-gal syndrome: clinical testing and diagnosis. US Centers for Disease Control and Prevention website. https://www.cdc.gov/alpha-gal-syndrome/hcp/diagnosis-testing/index.html. Updated June 26, 2025. Accessed May 25, 2025.
11. Commins SP. Diagnosis & management of alpha-gal syndrome: lessons from 2,500 patients. Expert Rev Clin Immunol. 2020;16(7):667-677.
12. Saretta F, Giovannini M, Mori F, et al. Alpha-gal syndrome in children: peculiarities of a “tick-borne” allergic disease. Front Pediatr. 2021;9:801753.
13. Platts-Mills TA, Schuyler AJ, Tripathi A, Commins SP. Anaphylaxis to the carbohydrate side chain alpha-gal. Immunol Allergy Clin North Am. 2015;35(2):247-260.
14. Cabezas-Cruz A, Hodžić A, Román-Carrasco P, et al. Environmental and molecular drivers of the α-gal syndrome. Front Immunol. 2019;10:1210.
15. Brestoff JR, Tesfazghi MT, Zaydman MA, et al. The B antigen protects against the development of red meat allergy. J Allergy Clin Immunol Pract. 2018;6(5):1790-1791.e3.
16. Alpha-gal syndrome. Cleveland Clinic website. https://my.clevelandclinic.org/health/diseases/24493-alpha-gal-syndrome.https://www.cdc.gov/alpha-gal-syndrome/about/index.html. Updated September 11, 2025. Accessed May 24, 2025.
17. Wilson JM, Schuyler AJ, Workman L, et al. Investigation into the alpha-gal syndrome: characteristics of 261 children and adults reporting red meat allergy. J Allergy Clin Immunol Pract. 2019;7(7):2348-2358.
18. Mabelane T, Basera W, Botha M, Thomas HF, Ramjith J, Levin ME. Predictive values of alpha-gal IgE levels and alpha-gal IgE: total IgE ratio and oral food challenge proven meat allergy in a population with a high prevalence of reported red meat allergy. Pediatr Allergy Immunol. 2018;29(8):841-849.
19. Humphrey N. Children’s mystery symptoms may be alpha-gal syndrome. VUMC News website. https://news.vumc.org/2023/04/13/childrens-mystery-symptoms-may-be-alpha-gal-syndrome/. Updated April 13, 2023. Accessed May 24, 2025.
20. Busing JD, Stone CA Jr, Nicholson MR. Clinical presentation of alpha-gal syndrome in pediatric gastroenterology and response to mammalian dietary elimination. Am J Gastroenterol. 2023;118(7):1293-1296.
21. Symptoms: a guide to understanding alpha-gal syndrome’s paradigm-shifting presentation. Alpha-gal Information website. https://alphagalinformation.org/symptoms/. Accessed May 26, 2025.
22. Shin M. Food allergies and food-induced anaphylaxis: role of cofactors. Clin Exp Pediatr. 2021;64(8):393-399.
23. Atopy defined. American Academy of Allergy Asthma and Immunology website. https://www.aaaai.org/tools-for-the-public/allergy,-asthma-immunology-glossary/atopy-defined#:~:text=Atopy%20refers%20to%20the%20genetic,inhaled%20allergens%20and%20food%20allergens. Updated July 8, 2024. Accessed May 26, 2025.
24. Ticks and alpha-gal syndrome. What you need to know to protect yourself. Alpha-gal Information website. https://alphagalinformation.org/ticks-and-ags/. Accessed May 25, 2025.
25. Butler WK, Oltean HN, Dykstra EA, Saunders E, Salzer JS, Commins SP. Onset of alpha-gal syndrome after tick bite, Washington, USA. Emerg Infect Dis. 2025;31(4):829-832.
26. Thompson JM, Carpenter A, Kersh GJ, Wachs T, Commins SP, Salzer JS. Geographic distribution of suspected alpha-gal syndrome cases — United States, January 2017–December 2022. MMWR Morb Mortal Wkly Rep. 2023;72(30):815-820.
27. Yang A. Chigger bites linked to red meat allergy. Yale Scientific. January 22, 2019. https://www.yalescientific.org/2019/01/chigger-bites-linked-to-red-meat-allergy. Accessed May 28, 2025.
28. Stoltz LP, Cristiano LM, Dowling APG, Wilson JM, Platts-Mills TAE, Traister RS. Could chiggers be contributing to the prevalence of galactose-alpha-1,3-galactose sensitization and mammalian meat allergy? J Allergy Clin Immunol. 2019;7(2):664-666.
29. Murangi T, Prakash P, Moreira BP, et al. Ascaris lumbricoides and ticks associated with sensitization to galactose α1,3-galactose and elicitation of the alpha-gal syndrome. J Allergy Clin Immunol. 2022;149(2):698-707.
30. Alpha-gal syndrome (AGS). Yale Medicine website. https://www.yalemedicine.org/conditions/alpha-gal-syndrome-ags. Accessed February 24, 2025.
31. Fast facts: products that may contain alpha-gal. US Centers for Disease Control and Prevention. https://www.cdc.gov/alpha-gal-syndrome/products-that-contain-alpha-gal/index.html. Updated June 26, 2025. Accessed May 26, 2025.
32. Reactions to airborne alpha-gal. Alpha-gal Information website. https://alphagalinformation.org/reactions-to-airborne-alpha-gal/. Accessed May 26, 2025.
33. Anaphylaxis. Food Allergy Research and Education website. https://www.foodallergy.org/resources/anaphylaxis. Accessed May 26, 2025.
34. Pattanaik D, Lieberman P, Lieberman J, Pongdee T, Keene AT. The changing face of anaphylaxis in adults and adolescents. Ann Allergy Asthma Immunol. 2018;121(5):594-597.
35. Platts-Mills TAE, Li RC, Keshavarz B, Smith AR, Wilson JM. Diagnosis and management of patients with the α-gal syndrome. J Allergy Clin Immunol Pract. 2020;8(1):15-23.
36. What is the vegan diet? International Food Information Council website. https://foodinsight.org/basics-of-vegan-diet/. Updated January 11, 2023. Accessed May 29, 2025.
37. Vegetarian diet. Medline Plus website. https://medlineplus.gov/vegetariandiet.html. Updated May 25, 2023. Accessed May 29, 2025.
38. What is the pescatarian diet? Cleveland Clinic website. https://health.clevelandclinic.org/pescatarian-diet. Updated April 22, 2025. Accessed May 29, 2025.
39. Mediterranean diet. Cleveland Clinic website. https://my.clevelandclinic.org/health/articles/16037-mediterranean-diet. Updated March 7, 2024. Accessed May 29, 2025.
40. DASH eating plan. National Heart, Lung, and Blood Institute website. https://www.nhlbi.nih.gov/education/dash-eating-plan. Updated January 10, 2025. Accessed May 29, 2025.
41. What is the flexitarian diet? Cleveland Clinic website. https://health.clevelandclinic.org/what-is-the-flexitarian-diet. Updated May 25, 2021. Accessed May 29, 2025.
42. Food: first steps. A guide for people with alpha-gal syndrome. Alpha-gal Information website. https://alphagalinformation.org/food/. Accessed May 29, 2025.
43. Sources of food ingredients: carrageenan. International Food Additives Council website. https://www.foodingredientfacts.org/facts-on-food-ingredients/sources-of-food-ingredients/carrageenan/. Accessed May 29, 2025.
44. Balzer D. Mayo clinic minute: a tick to blame for the alpha-gal, meat allergy. Mayo Clinic News Network website. https://newsnetwork.mayoclinic.org/discussion/mayo-clinic-minute-a-tick-to-blame-for-the-alpha-gal-meat-allergy/. Updated July 3, 2024. Accessed May 19, 2025.
45. Insect precautions — permethrin, deet, and picaridin. Indiana University Bloomington Student Health Center website. https://healthcenter.indiana.edu/health-answers/travel/insect-precautions.html. Accessed May 25, 2025.
46. Vector-borne disease section. California Department of Public Health website. https://www.cdph.ca.gov/Programs/CID/DCDC/Pages/Tick-Repellent.aspx. Updated January 7, 2025. Accessed May 29, 2025.
47. What to do after a tick bite. US Centers for Disease Control and Prevention website. https://www.cdc.gov/ticks/after-a-tick-bite/index.html. Updated July 15.2025. Accessed May 25, 2025.
48. Smith G. FDA approves ‘GalSafe’ pigs for food, medicine for alpha-gal allergy. Allergic Living website. https://www.allergicliving.com/2020/12/17/fda-approves-galsafe-pigs-for-food-medicine-for-alpha-gal-allergy/#:~:text=The%20U.S.%20Food%20and%20Drug,pigs%2C%20licensed%20to%20Revivicor%20Inc. Updated December 17, 2020. Accessed May 26, 2025.
49. Flaherty MG, Kaplan SJ, Jerath MR. Diagnosis of life-threatening alpha-gal food allergy appears to be patient driven. J Prim Care Community Health. 2017;8(4):345-348.