What could it be?! Thought it was healed

#1
I have a newly healed cyst, thought to have healed over in December. My doctor just gave me prescription ointment to put on it for a week and said to be very gentle. A couple months later and these last few days, noticed very itchy and tiny elevated skin area, like a bubble. Took a shower today and touched it and felt a minor sting.

There is a now a red spot where the wound was-- no pain or bleeding-- just a small red spot. I didn't have a red spot before when I thought it was fully healed. Maybe it was a thin layer of skin that was sensitive? Has anyone had a similar thing happen to them in the final stages of healing?