Hello,
Thanks for posting your query at DoctorSpring.com I can understand your concern. I reviewed the pictures.
I would give a possible diagnosis of a melanoma. However it could be an infected ingrown hair.
I recommend that you visit your dermatologist who can do a dermatoscopy and rule out the presence or absence of a melanoma and treat it accordingly.
For the time being you can apply Mupirocin cream twice a day for a week.
Please let me know if you have any queries.
Take care