Pimples, why?

A pimple is an infection. Anaerobic bacteria sometimes colonize a hair follicle and consume the sebum (oily substance) produced by sebaceous glands. They then excrete byproducts that irritate the surrounding area. The resulting inflammatory reaction calls in neutrophils (a type of white blood cell), which just come in and dumps bleach on the bacteria. As neutrophils die, they accumulate and form what we call pus or the “white stuff”. It only has one immediate way out; through the hair follicle to the skin surface. That’s why it exists the way it does.

If left untouched, after a few days the pimple will resolve following absorption back into the body.