I Had 3 Internal And 3 External Stitches On The

I had 3 internal and 3 external stitches on the back of my shoulder as a preventative measure to remove a mile with abnormal cells. The external stitches were removed a week ago and were surrounded by a red bumpy rash. The doctor told me it was from the Bandaid and to simply keep it clean. It's been a week and the rash hasn't changed. I'm actual allergic to metals in costume jewelry and also currently have a rash on my legs die to hives which despite taking a dermatologist prescribed antihistamine, has not subsided. Can this new rash be dangerous? Should I go back to this dermatologist or seek out another specialist?