Acne usually comes from blackheads. When oily, dead cells are trapped in pores, they block the duct and mix with bacteria, then they become blackheads.
When blackheads become inflamed, red pimples emerge. If hands touch red pimples, they spread quickly.
When a pimple becomes infected, it causes whitehead or pustule.
Cheese and chocolate do not cause acne. But mental stress, bad cosmetics, hormones, and birth control pills, normally cause adult acne.
For serious acne, a dermatologist can safely clear your acne. A good facial care will always be important.