'Doc, will I ever eat steak again?': diagnosis and management of alpha-gal syndrome.

Abstract

Alpha-gal syndrome encompasses a constellation of symptoms associated with immune-mediated hypersensitivity responses to galactose-alpha-1,3-galactose (alpha-gal). The purpose of this review is to discuss our current understanding of the etiology, clinical symptoms, natural history, epidemiology, and management of alpha-gal syndrome. Sensitization to alpha-gal is associated with bites from ectoparasites like the lone star tick Amblyomma americanum. Allergic reactions in alpha-gal syndrome are often delayed and inconsistent. The magnitude of the allergic response depends on co-factors like exercise and alcohol consumption and the amount of alpha-gal and fat present in the food. Assaying alpha-gal-specific IgE in the serum is the primary diagnostic test used to confirm the allergy. Long-term management of the condition involves avoidance of both mammalian food products and tick bites. Alpha-gal syndrome disrupts the current paradigm for understanding food allergy. Exposure to an ectoparasite is critical for the development of specific IgE antibodies underlying sensitization, and allergic reactions depend on the activation of mast cells and basophils sensitized with IgE against a carbohydrate rather than a protein. Research in this field may lead to the development of improved diagnostic and therapeutic tools that can revolutionize the management of patients with alpha-gal syndrome.