How Do Blackheads Form
Blackheads look like dark spots that form on your skin. Blackheads are called open acne. Pimples are colored bumps that form when you break out. In the case of blackheads, these pimples consist of hair follicles under the skin that have very large openings, or pores.
When you have blackheads, these large pores get clogged with a substance called sebum. The chemical reaction with sebum happens under your skin. Melanin is oxidized, turning clogged pores black. This form of acne usually appears on your back, shoulders, and face.
How Do Whiteheads Form
Whitehead acne is called closed acne. The hair follicles under the skin are full of bacteria and there is a very small opening at the top of the skin. Air cannot enter the hair follicle. The bacteria inside don't react chemically, so the color stays white. This type of acne also appears on your back, shoulders, and face.