Welcome to health care magic.
1.The history and symptoms suggest the most possible cause is hair follicular infection / inflammation in the first place.
2.The next possible cause could be
abscess with collection of the infective material / pus with in.
3.In both cases i would recommend you not to interfere the lump by scratching, pressing as in that way you will increase the infection and complicate the condition.
4.At this point i maintain local hygiene, clean the area with antiseptic liquid - soft and gentle. And need a course of antibiotic therapy that will heal the infective process.
5.If the lumps are big and complicated stage, it may need a small
incision and drainage followed by antibiotics and dressing.
Good luck.
Hope i have answered your query,
any thing to ask ? do not hesitate to ask.
http://doctor.healthcaremagic.com/doctors/dr-ganesh/62888