stubborn whiteheads on chin?

I would go to dermatologist since it's not always whiteheads - at least what I see on this photo looks bit suspicious, but as you said it's not your photo plus on the Internet it's not that easy to read skin condition from a photo - nothing is better than face to face visit at dermatologist department or office. I believe if your skin condition is just whiteheads, your dermatologist will recommend retinoid treatment :)