You seem to have recurrent development of folliculitis
over the scalp...
Some general precautions include: washing your scalp regularly and avoiding the use of hair oil..instead you can use hair conditioners after washing your hair..
As you also have itchy scalp,so you might just be having some degree of dandruff(seborrhea capitis).
Now i would not recommend that you should start with oral antibiotics
of your own,,instead you can use some topical agent like mupirocin
gel or metronidazole
gel over the affected area twice a day for 3-4 days,,,If you still feel the lesions are not improving, then you might need to consult a dermatologist
for proper assessment and treatment...
Hope it helps
Dr Geetika Paul