I Had What I Thought Was An Allergic Reaction To

I had what I thought was an allergic reaction to new soap on my chest 3 days ago. One welt popped up immediately. I switched back Tommy old soap and washed the are and took a benedryl. The next day it was flat but red. Apperantly I scratched it in my sleep so I used benedryl cream. Now it appears pussy. Will that heal on its own or does a Dr need to take care of it?