This is what a foot looks like when you are stung by a wasp and you have a very strong immune reaction to its poison. I have always swollen up when I get bitten by mosquitos. It has been a number of years since I have had a wasp or bee sting so I'd forgotten how my body reacts. This is what my foot looked like about 24 hours after the sting. It got worse even after this. I went to the doctor's on Monday and was prescribed an antibiotic. That and benadryl have helped. Today, it is finally starting to subside but you can still see bruising and some swelling.