It seems that you are having seborrheic keratosis
Seborrheic keratoses are noncancerous (benign) skin growths that some people develop as they age.
They often appear on the back or chest, but can occur on any part of the body.
Seborrheic keratoses grow slowly, in groups or singly...
Now , you may be having secondary bacterial infection.
Take antibiotics for 2 weeks...and Apply antibiotics till infection clears.
Then, you may go for electrocautery for complete recovery.
It is an OPD procedure, done under local anaesthesia.
Do not worry, you will be alright.
Just consult an expert dermatologist
and go for treatment.
I hope you got my answer.
Dr. Ilyas Patel MD