Physicians in the eastern and midwestern United States should consider alpha-gal allergy among patients with unexplained abdominal pain, diarrhea, nausea and vomiting, according to new guidance from the American Gastroenterological Association.
This increased vigilance is particularly applicable for those patients who live or have lived in an alpha-gal–prevalent area, which includes the Southeast, mid-Atlantic, Midwest and East Central regions of the United States.
A result of the bite of a lone star tick, alpha-gal syndrome causes an allergic reaction to eating mammalian meat and other food products derived from mammals, such as dairy. Symptoms of GI distress usually begin two to six hours after eating mammalian food products; in patients presenting with these symptoms, a blood test to check for immunoglobulin E antibodies to alpha-gal should be conducted, as patients with these antibodies may have an alpha-gal allergy. Treatment for alpha-gal allergy is a diet excluding mammalian meat and other products.
“Patients are showing up to GI clinics because the allergic reaction can manifest with GI symptoms alone, without rash or facial swelling or other ‘typical’ allergic reactions,” guidance author Sarah McGill, MD, an associate professor of gastroenterology and hepatology at the University of North Carolina at Chapel Hill, told Gastroenterology & Endoscopy News. “The current paradigm is that GI doctors should rarely think about food allergies, because those are problems of kids, not adults, and symptoms in allergies should occur reproducibly after exposure.
“That’s just not true in alpha-gal allergy. Mostly this has been reported in adults, and the delay of hours from eating the meat to reaction means that almost no patient can actually link the two.”
According to Dr. McGill, a leading expert in the field of alpha-gal, the syndrome is still under the radar, but GI clinicians should familiarize themselves with this condition, its often-challenging presentation and the necessary steps for its diagnosis and management. The guidance was published in the journal Clinical Gastroenterology and Hepatology (2023;21[4]:891-896).
—Meg Barbor, MPH
