greatblackskin.com-What is Acne?

Acne is a disease that affects the skin's oil or sebaceous glands. The small holes in your skin (pores) connect to oil glands under the skin. These glands make an oily substance called sebum. The pores connect to the glands by a canal called a follicle. Inside the follicles, oil carries dead skin cells to the surface of the skin. A thin hair also grows through the follicle and out to the skin. When the follicle of a skin gland clogs up, a pimple grows as a result of accumulation of excess sebum and overgrowth of the skin around the area.

Excess sebum also creates ideal conditions for infection of the follicle by the bacteria Propionibacterium acnes. This now leads to inflammation and a collection of pus in the pimple.
Most pimples are found on the face, neck, back, chest, and shoulders. More...