Emerging Clinical Complications of Alpha-Gal Syndrome: A Scoping Review.
Alpha-gal syndrome (AGS) is characterized by an IgE-mediated immune response against galactose-α-1,3-galactose (α-gal). In the United States, the principal vector is the lone star tick, whose range has expanded nationwide. A lone star tick bite delivers α-gal into human skin via its saliva, triggering an IgE response in susceptible individuals. Vomiting, urticaria, and anaphylaxis may occur immediately or hours after exposure. However, perioperative ingredients, such as gelatin, monoclonal antibodies, stearic acid, and other mammalian-derived products, have triggered anaphylactic shock in patients with AGS. These nuances complicate AGS management as many cases go unrecognized. This review aims to look beyond traditional food-related reactions, characterize the range of presentations, and improve management of this increasingly recognized condition. The inclusion criteria required original research in English peer-reviewed journals between January 1, 2000, and March 22, 2026. Eligible studies included quantitative, qualitative, and mixed-method designs examining AGS acquisition. Relevant tick studies were included. Systematic reviews, scoping reviews, meta-analyses, case reports, series, and studies involving pregnant individuals or children, lacking full-text, duplicate publications, or overlapping datasets were excluded. Authors screened publications using Rayyan (Rayyan Systems Inc., Cambridge, USA). Discrepancies were resolved through discussion. Of the 729 records identified, 14 studies met the inclusion criteria. Understanding the diverse spectrum of allergic manifestations of this condition is vital. This review consolidates findings on AGS-related complications, including immediate and delayed anaphylaxis, hypersensitivity reactions to mammalian-derived medical products, and blood transfusions. However, the available evidence is primarily derived from observational studies conducted in the United States, which may limit the generalizability of current findings. By highlighting the broader implications of AGS, this review underscores awareness in acute and perioperative settings.