Welcome to Heathcare Magic Physician's Desk!
The lesion of this type can be any thing-
a mole, a furuncle
, a fungal infection
, eschar of insect bite.
I would be of great help if you could upload a photograph.
Optionally you can get examined by your dermatologist
because diagnosing it just by narration can be misleading.
Wish you a great health!