could be due to hormonal derangement. In such cases, usually there are complaints of coarse hair growth, irregular menses, oily coarse skin, dandruff and hair fall along with cystic nodular acne
To diagnose the same, you might need to to undergo few tests and a pelvic ultrasonography
. So consult a gynaecologist or dermatologist
for the same as acne treatment depends upon severity and cause of the lesion.
To treat the same, you might require a course of oral and topical anti acne drugs, hormonal pills etc.
Hope that answers your query. Take care.