My son ate a fabric sheet

My son ate a fabric sheet. I was doing laundry and he likes to pull things out of the dryer while I'm folding. He must have gotten a fabric sheet because he started choking and coughing and I tried to pull it out but he swallowed it. He got hives and a rash shortly after but he seems to be breathing fine. I called the Dr and she said to keep an eye on him. I know I should have been paying attention better but has this happened to any other moms out there? Or anything similar?