Joe:
Whatever it is, is certainly is neither melanoma or scabies. This sounds more like an irritation or perhaps (unlikely) a fungus infection.
My advice is to apply some over-the-counter hydrocortisone once a day in the morning, and some
clotrimazoleClotrimazole
Clotrimazole topical (also OTC) at night. If it's not gone after 2 weeks, show it to a doctor, but I bet it will be (gone.)
Best.
Dr. R