Thanks for presenting your problem to us.
You are having a skin infection
that could be folliculitis
. This starts when hair follicles are damaged by clothing, blockage of the follicle, shaving etc Most of the time will be infected by staph. The present as pimples and may crush over. Treatment will be use of topical (e.g clindamycin
cream) or oral (e.g cloxacillin) antibiotics that can fight against staph infection. Also possible that your affection might be of fungal origin ( tinea cruris
) and would need antifungal such as miconazole cream.
If you are sexually active, a much further investigation could be done by your doctor to rule out the presence of syphilis ( most unlikely given your description).
A visit to your doctor or a dermatologist
will be well decided.
Hope this helps