AGA Family of Websites:
Clinical Practice Update

Diagnosis and management of alpha-gal syndrome

New guidance helps you identify if unexplained digestive symptoms are due to alpha-gal syndrome, a food allergy caused by lone star tick bites.

Guideline Tool kits

Members only access the guideline tool kits


Gastroenterologists should be aware of the diagnosis and management of alpha-gal syndrome because a subset of alpha-gal allergic patients show GI symptoms such as abdominal pain, diarrhea, nausea, or vomiting without skin changes or anaphylaxis. The diagnosis of alpha-gal syndrome can be made among patients with GI distress and increased serum alpha-gal IgE antibodies whose symptoms are relieved adequately on an alpha-gal–avoidance diet that eliminates pork, beef and mammalian-derived products. Patients with suspected alpha-gal allergy should be counseled on an alpha-gal–avoidance diet because that is the primary management. Counseling also should include measures to avoid tick bites because further bites can drive alpha-gal IgE titers higher and worsen the allergy. Patients who also have reactions such as facial swelling, urticaria and respiratory difficulty should be referred to allergists. GI alpha-gal syndrome recently was described and prospective studies are needed to better understand this condition.