I just have the same problem right now what should i do?
Hello,
From the symptoms it can be collected sebum at the end of a hair follicle causing sebaceous cyst. A sebaceous cyst is a closed sac occurring just under the skin which contains a "pasty" or "cheesy" looking substance called keratin. It may appear black in color when infected and may also give a foul smell.
I suggest you to get an examination done from a dermatologist.
I hope it helps. Take care and regards.