American Academy of Allergy, Asthma & Immunology Annual Meeting

American Academy of Allergy, Asthma & Immunology Annual Meeting


Platt J, et al. Abstract L29. Presented at: AAAAI Annual Meeting; Feb. 25-28, 2022; Phoenix (hybrid meeting).

Disclosures: The Storer Foundation and charitable contributions to Tick-Borne Conditions United provided funding for this study. Platt and Merritt report no relevant financial disclosures.
March 01, 2022
5 min read

Patients with alpha-gal syndrome report ‘wide range’ of previously undocumented symptoms


Platt J, et al. Abstract L29. Presented at: AAAAI Annual Meeting; Feb. 25-28, 2022; Phoenix (hybrid meeting).

Disclosures: The Storer Foundation and charitable contributions to Tick-Borne Conditions United provided funding for this study. Platt and Merritt report no relevant financial disclosures.
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PHOENIX — Patients with alpha-gal syndrome reported many physical and mental effects along with a profound quality-of-life impact, according to survey results presented at the American Academy of Allergy, Asthma & Immunology Annual Meeting.

Understanding the vast range of symptoms that can indicate alpha-gal syndrome (AGS) — the first known carbohydrate-based allergy to mammalian-derived ingredients, which is associated with tick bites — is essential for diagnosing clinicians, according to the researchers.

Lone star tick
Source: Adobe Stock

“A lot of health care providers still are not aware of AGS, and providers who are aware of it do not understand the full range of symptoms,” Jennifer Platt, DrPH, cofounder and director of Tick-Borne Conditions United and adjunct professor at University of North Carolina Gillings School of Global Public Health, told Healio. “AGS impacts every body system. Many patients are still told, ‘it's all in your head,’ prescribed anxiety/depression medication, and sent on their way.

Jennifer Platt, DrPH
Jennifer Platt

“Our first priority was to raise awareness of the disease, and then right behind that to raise awareness of the extent of the body systems it affects and the range of symptoms that can be experienced,” Platt added.

Patient symptoms, experiences

To explore the patient experiences and range of symptoms for those with AGS, Platt and Tina Merritt, MD, FAAAAI, of Allergy & Asthma Clinic of Northwest Arkansas, conducted an online pilot survey that they distributed to 20 patients with AGS, 13 of whom responded. Because AGS lacks a coded diagnosis, the researchers used a “snowball” sampling distribution method, so that those first responding patients could share the link with other patients, as well as widely to patient groups, listservs and social media groups.

In total, 2,122 patients have participated in the survey, with a 63% completion rate.

The survey collected baseline demographics and asked whether patients are self-diagnosed or formally diagnosed with AGS, if they have had exposure to ticks or have been diagnosed with tick-borne diseases, what medical symptoms they have experienced, and about other social and financial impacts.

Results of the survey showed that the most common mammalian ingredients and items that patients reacted to included beef (96%); pork (85%); dairy (60%); gelatin in food or medicine (55%); personal care products, such as shampoos and tampons (36%); prescription (35%) or over-the-counter (30%) medicines; lamb (34%); and venison (28%). Although less common, patients also reported having reacted to household cleaning products (27%), vaccines (13%), textiles (11%) and dental/surgical medical supplies (10%).

“There are some patients who are very, very sensitive, and they can’t even be around fumes,” Platt said. “For many people this is completely life-altering; it goes beyond just not eating [red] meat. It affects their ability to go to restaurants or to go to gatherings with family and friends.”

There are also many bizarre items that one would not associate with having mammal products in them, Platt said, such as crayons, asphalt, leather goods and cleaning products. Some people also react to carrageenan, an extract of seaweed that appears to be cross-reactive.

When asked about timing of reactions related to exposure, 52% of patients experienced reactions 4 to 6 hours later — delayed reactions are one of the hallmarks of AGS, Platt said — although 11% of patients said they experienced reactions within 5 minutes.

“It can be really traumatic for patients and their family when they realized they’ve had an accidental exposure,” Platt said. “I’ve heard from patients who will go and sleep in their car in the emergency room parking lot, waiting for a reaction to happen.”

In terms of symptoms, many patients reported those that are most commonly associated with AGS, including those that affect the skin (88%), as well as gastrointestinal (82%) and respiratory (64%) symptoms. However, researchers noted the survey responses revealed a “wide range of previously undocumented symptoms,” including those within the cardiovascular (41%), emotional (35%), nervous system (22%) and motor (22%) body systems.

“To our knowledge, the extensive range of mental health symptoms experienced has not yet been documented in the medical literature,” Platt said, adding that patients described experiencing anxiety, confusion, depression, fatigue, poor memory recall, irritability, a feeling of “impending doom,” panic, sleep disturbances, and withdrawal from social and recreational activities.

Patients also reported a financial toll, with some spending thousands on medical tests and surgeries for misdiagnoses.

Also, 12% of patients indicated they had been diagnosed with Lyme disease. Platt noted this is important because patients with Lyme may not feel better if they are being treated with mammal-containing medications.

She also said that although the Lone Star tick is mostly commonly associated with AGS in the U.S., “we know that black-legged ticks (or deer ticks) also have alpha-gal in their saliva. No studies have yet proven impact on humans in the U.S., although in Europe, other Ixodes have been associated with AGS.”

Overall, clinicians should be aware of the vast range of symptoms that may indicate AGS, as well as the characteristically delayed reaction time.

“Listen to your patients, because they have their gut instinct when something is wrong,” Platt said. “Any patients who present with random, unexplained GI symptoms, or anaphylaxis in the middle of the night, should be tested for alpha-gal.”

A ‘life-changing’ diagnosis

The impact of AGS appears to be ongoing, with 37% of patients reporting having 15 or more reactions prior to diagnosis, 25% still reacting at least once a month and 39% having visited the ED due to a reaction.

Moreover, only 8% of patients reported having had their symptoms resolve over time.

That figure may seem surprisingly low given some anecdotal accounts of patients reporting being able to tolerate eating meat years after having been diagnosed with AGS.

For instance, a case report presented at AAAAI by Ari Heffes-Doon, MD, BA, and colleagues reviewed the clinical presentation of a 52-year-old male who experienced generalized urticaria and angioedema 8 hours after eating beef with a history of multiple tick bites. He had an initial alpha-gal specific IgE of 39.9 kU/L and abstained from eating meat over the next 5 years. Once his alpha-gal sIgE levels gradually decreased to 1.77 kU/L, he underwent an oral challenge of 100 g of ground beef and remained asymptomatic over an 8-hour observation. He now eats meat freely without experiencing any effects.

But which patients are likely to go on to tolerate meat remains a “black box,” Platt said.

“Given the patient anxiety and breadth of symptoms, I do not know many patients who would undergo an oral challenge with an sIgE of 1.77 kU/L,” she said.

To meet the challenges faced by patients with AGS, scientists have also begun engineering pigs to remove the allergen, alpha-gal. A report at AAAAI by John R. Bianchi, PhD, vice president of product development at Revivicor, describes the company’s “GalSafe” pig that has an inactivated GGTA1 gene. Analyses of tissues from these pigs showed comparable nutrient value to standard pigs, while immunohistochemistry analyses showed that sera from patients with AGS did not react to the samples.

But until such meat products become widely available and accepted, the majority of patients with AGS are likely to have to abstain from meat and other products for the foreseeable future.

“This is literally a life-changing diagnosis,” Platt said. “If someone finds out they have this, it changes their lives.”


  • Bianchi JR, et al. Abstract 608. Presented at: AAAAI Annual Meeting; Feb. 25-28, 2022; Phoenix (hybrid meeting).
  • Heffes-Doon A, et al. Abstract CA04. Presented at: AAAAI Annual Meeting; Feb. 25-28, 2022; Phoenix (hybrid meeting).
  • Platt J, et al. Abstract L29. Presented at: AAAAI Annual Meeting; Feb. 25-28, 2022; Phoenix (hybrid meeting).