I am left with red scar on top of my lips after an allergic reaction and cold sore. 2 months now. What can I do?

I had a cold sore on my upper lip and an allergic reaction to oysters at the same time. My upper lip got very swollen. The cream that I used had cortisone in it and after using it and didn't help. Went to the pharmacy who confirmed the allergic reaction and gave me allergy pills and Zovirax cream for the cold sore. I am left with a redness type of scar on my upper lip and skin for over 2 months now. What can I do?