Hello,
After liquid nitrogen treatment, you should leave the area open to the air if possible. It may take 5-10 days for complete healing. Sometimes there is oozing from the wound. In that case, please apply Neosporin cream . You may notice a darkening or lightening of the pigment in the areas where the liquid nitrogen has been used. This may be temporary or permanent.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.