I Was Bitten On The Foot 11 Days Ago By

I was bitten on the foot 11 days ago by a yellow jacket/wasp. The area swelled and was itchy and then went away. 7 days after the sting, I noticed that I was developing a rash on my chest that itched but did not ooze. I have had the rash for 4 days and it has spread onto the back of my arms and upper back. I was just prescribed prednisone by my family doctor who didn't know what could be the cause of the rash. I was wondering if it was possible that it could be a reaction to the bee sting?