Persisting white bumps for over a year!

Patient: I have small white bumps across my forehead. They’ve been there for a year now and sometimes dies down slightly and sometimes more pops up but it’s never been clear. They don’t hurt or itch. I think they may be whiteheads or subclinical acne but I’m not sure… Any ideas? Would benzac help the situation or would it be too strong for my case?