Chirag Patel, MD, explains why reaction timing, isolated abdominal pain, and careful test interpretation are central to recognizing alpha-gal syndrome.
Delayed reaction timing and isolated abdominal pain are the clinical clues most likely to help clinicians recognize
Alpha-Gal Syndrome Moves North, Yet Diagnoses Lag Behind I Perspectives from Chirag Patel, MD (Hackensack Meridian Health), Shaun Cross, PhD (University of Nebraska Medical Center), and Benjamin W. Casterline, MD, PhD (University of Missouri School of Medicine)
The lone star tick (Amblyomma americanum) is now established on Long Island and in Massachusetts, bringing AGS into regions where many clinicians have little experience with it. A 2022 CDC survey of 1,500 health care providers found 42% had never heard of the condition, and fewer than one-third of those familiar with it knew how to diagnose it.¹ Suffolk County, New York, recorded among the highest numbers of suspected cases identified through testing from 2017 to 2022.²
“With alpha-gal, you really have to think outside the box a little bit,” Patel said. “It’s easy to characterize them as chronic spontaneous hives or acute hives because viruses are one of the most common reasons for getting those.”
Patel said the first step in evaluation is establishing when reactions occur. In contrast with peanut allergy, in which symptoms appear soon after ingestion, alpha-gal reactions are typically delayed. Patients frequently describe hives emerging in the evening or the middle of the night.
“There’s a pattern to it, whereas chronic spontaneous urticaria would occur at any time,” Patel said.
For clinicians in regions newly reached by the lone star tick, Patel identified tick bite history as the first question to ask. He noted a tick does not need to remain attached for the 48 to 72 hours associated with Lyme disease transmission, as a bite alone can lead to alpha-gal sensitization. He also advised asking patients how much mammalian meat they actually consume.
Patel said awareness among his peers has grown considerably. Five years ago, mentioning alpha-gal syndrome to colleagues often drew confusion; now most clinicians he speaks with know something about it, even if they cannot describe it in detail. He credited media coverage and the northward movement of ticks, which he linked to climate change, with bringing the condition to clinicians’ attention.
Early descriptions of AGS centered on a typical IgE-mediated presentation, with hives, sweating, and other features of an allergic reaction appearing 4 to 6 hours after a meal. Patel said many patients present with abdominal pain alone.
He pointed to South African oral food challenge studies in which about 20% of women reported abdominal pain as their sole symptom. A 2025 review in the Cleveland Clinic Journal of Medicine cited a study where 40.7% of the 91 patients with AGS experienced exclusively gastrointestinal symptoms.³
“If somebody comes in with abdominal pain, they don’t think this is IgE-mediated,” Patel said. He described isolated abdominal pain as the presentation most often missed and frequently redirected to gastroenterology.
Patel cautioned against treating alpha-gal IgE values as a diagnosis, particularly in patients without symptoms. He described food allergy testing as carrying a false-positive rate of roughly 50%, making it a risk assessment tool. A larger value signals a greater probability of clinical allergy, not a more severe allergy, despite laboratory reports labeling results as mildly or highly allergic.
“Either you’re allergic or you’re not,” Patel said.
Patel also flagged misinformation circulating about the condition, including claims tying brain fog to alpha-gal syndrome, which he said are not supported by clinical data.
“Awareness is probably the most important thing,” Patel said. “The other thing is to be aware of all the misinformation. There are people who write books about Alpha Gal who don't even have [it]. If you have random reactions that have features of an Ig-mediated reaction, then you should probably consider alpha-gal as part of your differential.”
Read our latest feature on alpha-gal syndrome here:
Editor’s note: Reported disclosures for Patel include AstraZeneca Pharmaceuticals, GENZYME CORPORATION, Grifols USA, LLC, ARS Pharmaceuticals Operations, CSL Behring, Novartis Pharmaceuticals Corporation, Lilly USA, LLC, Pharming Healthcare, Insulet Corporation, Verona Pharma, Takeda Pharmaceuticals U.S.A., Inc, Amgen Inc, Incyte Corporation, PFIZER INC, and more.
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