What to know about dangerous meat allergy caused by tick bites

Key Points:

• Alpha-gal syndrome is a life-threatening allergy to mammal meat triggered by tick bites, particularly from the lone star tick, which introduces alpha-gal sugar into the bloodstream, causing the immune system to develop antibodies that react to meat and sometimes dairy.
• Cases of alpha-gal syndrome are increasing due to greater awareness and the expanding habitat of the lone star tick, now found beyond its traditional range in the eastern and southern U.S., with an estimated 450,000 Americans affected.
• Diagnosis involves blood tests for alpha-gal antibodies combined with symptom assessment, as tests alone can yield false positives; symptoms include hives, digestive issues, and severe allergic reactions.
• Treatment traditionally involves avoiding mammal meats and carrying epinephrine injectors, but in 2024 the FDA approved Xolair, an injectable drug that reduces severe allergic reactions, though it does not cure the allergy.
• The allergy may fade in some individuals over several years if new tick bites are avoided, and ongoing research is exploring other biologic drugs that might prevent or mitigate the allergic response.