Hi. You should not worry about this. But requires immediate attention. Looks like bacterial infection because of recurrent folliculitis. It could also be peri anal fistula if it is close to anal orifice. This is generally recurrent condition and requires intervention.
For the rash , in between hips , you may try using Bifocan cream twice daily. Also apply Vaseline Petroleum jelly twice daily.
Next Steps
Immediately consider consultation with a dermatologist.