My DS reacted to cashew at 16 months. It was the scariest day of my life watching helpless as he swelled and his body became covered head to toe in hives.
Luckily he was blue lighted to hospital within 10mins, not so easy on an plane.
He's a beautiful toddler now and avoiding nuts and tree nuts (allergic to both) is the cause of much stress. Restaurants, parties, celebrations, Xmas, Easter etc the worry never leaves.
He's such a good boy and do accepting of his allergies and not being able to eat what everyone else is. But seeing his face drop when once again he can't have a biscuit/chocolate/ ice cream is so heartbreaking.