My son, now 6, was diagnosed with FPIES to oats as an infant. We were careful in introducing other foods and never came across any other triggers. When he was about 4 years old, we reintroduced oats successfully and he has been fine since. He also has regular IgE allergies to dairy and peanuts. Recently, he has had two episodes of sudden and profuse vomiting, and on both occasions had eaten an almond-based yogurt substitute (not something he usually eats) a few hours before. I would have thought it was a regular short-lived stomach bug, except that he has been home due to COVID for weeks and shouldn’t have been exposed to much for germs. The reactions were so much like his FPIES reactions as an infant - vomiting violently and repeatedly, acting very lethargic, lasting about 2-4 hours, then returning to his usual self as if nothing had happened! The only thing is, there shouldn’t be any ingredients in the food he ate that he can’t have. He doesn’t particularly like almonds, but has eaten almond products on many occasions safely for years. Everything says it shouldn’t be FPIES, except that these reactions are JUST like his previous FPIES reactions and nothing like anything else we’ve experienced. Is it possible that he could develop FPIES to a new food at 6 years old??