I recently got a benign melanotic macule spot frozen on my lower lip with liquid nitrogen.The spot is on the vermilion of the lip. I have done this before with no issues. This time the scab came off and I have a small ghost white spot on my lip. The scab came off 6 days ago and the white spot has been there since. The rest of the spot where the scab was is a reddish color and slightly puffy, which seems normal. Please advise.