Tick bites can trigger a mammal-meat allergy: the rise of alpha-gal syndrome and new treatments

Alpha-gal syndrome is a mammal-meat allergy triggered when certain ticks inject the sugar alpha-gal into the bloodstream, provoking antibodies and reactions hours after eating beef, pork, or lamb. Cases are rising as tick habitats expand, and diagnosis combines symptoms with blood tests (which can yield false positives). Management centers on avoiding mammal meats and certain byproducts; a small number of pigs engineered to lack alpha-gal (GalSafe) are FDA-approved for consumption, and the FDA approved Xolair (omalizumab) in 2024 to reduce severe reactions, with more therapies in the works. The allergy can fade in 15–20% of people after years with strict tick-bite avoidance.