These symptoms suggest folliculitis, a very common and highly treatable inflammation of the hair follicles, often caused by friction, sweat, or bacteria. To treat this, keep the area clean, dry, and wear loose-fitting clothing. Applying a warm compress for 10 minutes a few times a day can help soothe the pain and drain the pus. For medication, washing the area with a generic benzoyl peroxide wash is helpful. For the active pus-filled bumps, applying a generic topical antibiotic ointment, such as mupirocin, twice daily will help clear the infection. Avoid popping them. If the rash worsens or does not improve in a few days, please see a doctor.