PHOENIX (Nov. 12, 2026) – The summer of 2026 was a particularly bad season for ticks. And with it came a rising number of cases of alpha-gal syndrome (AGS) thanks to bites from the Lone Star Tick. A new study presented at the American College of Allergy, Asthma and Immunology (ACAAI) 2026 Annual Scientific Meeting shows that a biologic treatment already in use for allergic asthma, food allergies and chronic hives may help protect people with AGS. A separate report on a medically challenging case shows how often doctors miss the allergy, and how it can affect mental health.
AGS occurs following a bite from the Lone Star tick. The bite can make the body react to alpha-gal, a sugar found in red meat such as beef, pork and lamb. It can also be found in some dairy foods and other products made from mammals. Between 96,000 and 450,000 Americans may have AGS. Unlike most food allergies, the reaction often starts hours after eating. That delay makes it hard to connect the reaction to the food.
The first study looked at 64 people with AGS who were treated with omalizumab (Xolair). The medicine is a biologic given as a shot and is already used to treat other allergic conditions. Before treatment, 81% of the patients had experienced a severe, allergic reaction called anaphylaxis. More than half had needed epinephrine.
While taking omalizumab, none of the patients needed epinephrine for a food reaction. Almost all of them (95%) said their reactions happened less often or were less severe. About one in three were able to add some or all red meat or mammal products back into their lives. Side effects were uncommon and mostly mild, such as joint pain. Only two patients stopped the medication because of side effects.
"Even patients who are very careful about avoiding mammalian products can experience accidental exposures and reactions, said Collette M. Tilly, MD, lead author of the study and ACAAI member. "In our study, patients treated with omalizumab had fewer or less severe reactions, and none required epinephrine for a food-related reaction while on therapy. These findings suggest that omalizumab may offer an additional layer of protection for patients living with alpha-gal syndrome."
The second study describes a medically challenging case. A 66-year-old man who previously had a tick bite broke out in hives, started coughing and had trouble getting enough oxygen. Both times, it happened hours after eating red meat and drinking alcohol. Because he was sometimes able to eat red meat with no problem, AGS was not the first thing suspected by his physician. A blood test finally showed he was highly allergic to alpha-gal. He was given epinephrine to carry and told to avoid red meat. He was also warned that alcohol can make reactions worse.
"In this case, even an experienced physician didn't think of alpha-gal at first, and that happens frequently," said Jeffrey Yu, MS, lead author and ACAAI member. "On average, people wait about seven years to get the right diagnosis. As ticks spread to more regions in the US, a simple blood test for alpha-gal could save lives."
The authors note that in 2025, a New Jersey man became the first known person to die from AGS. They also point out that AGS affects more than the body. About two out of three people with AGS report anxiety or depression. More than half avoid social events that involve food.
"Living with AGS means worrying about every meal," said Yu. "Patients need mental health support along with good medical care."
Abstract Title: Omalizumab Eliminates Epinephrine Use and Reduces Anaphylaxis Burden in Alpha-Gal Syndrome
Presenter: Collette Tilly, MD
Abstract Title: Alpha-Gal Syndrome: An Underrecognized Cause of Delayed Anaphylaxis With Potential Impact on Mental Health
Presenter: Jeffrey Yu, MS
People who think they may have AGS should see a board-certified allergist. An allergist can test for alpha-gal and create a treatment plan. To find an allergist near you, visit AllergyandAsthmaRelief.org The ACAAI Annual Scientific Meeting is Nov. 12-16. For more news and research from the ACAAI Scientific Meeting, go to our newsroom and follow the conversation on X/Twitter #ACAAI26.
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