The Myth of Poison Ivy

Over time over repeated exposure to poison ivy even those long head T cells figure out like oh you're a pal I don't have to mess with you. The macrophages come in and indiscriminately just start eating everything and damaging the tissue. There can be something called delayed hypersensitivity. It could take hours or it could take days. You might think you're all good in a few days later. You're going to get it. And it's not from scratching or spreading. It's because just that delayed response.