Alpha-gal syndrome is spreading in the US. Here’s what to know about the tick-borne illness that can cause fatal red meat allergies

Alpha-gal syndrome, a tick-borne illness that can cause people to develop a life-threatening allergy to red meat, is spreading across the U.S.

Researchers estimate that as many as 450,000 Americans may be living with the syndrome, according to Stony Brook Medicine, most of whom are unaware they are affected until sudden and concerning allergic reactions occur.