Welcome to HCM.
It usually occurs due to hair ingrowing.
You have to take complete course of oral antibiotic like amoxy/clavulinic 625 with nsaid
to subside pain,inflammation and infection.
Do regular cleaning and dressing with antiseptic liq and antibiotic cream.
If it is recurrent than you have to go for surgery for permanent cure.Laser
burning of hair of that area is also advisable to prevent recurrence.
Better get examined by surgeon and ask him.