If there is no wick, the pool of oil collects. The sebum produced also is thicker and stickier in acneic skin types. Acneic skin also produces four to five times more skin cells inside of the follicle than normal skin. This may not be a problem except that these cells stay in the follicle because the skin isn't exfoliating sufficiently. When hair follicles fill with excess oil from the sebaceous glands and an accumulation of dead cells, a favorable environment for bacteria is created.
Blackheads form and create a blockage at the mouth of the follicle.
These follicles often swell and rupture, causing the debris to escape into the skin, irritating it and producing an inflamed red bump. The further underneath the skin the follicle breaks, the longer it takes to heal the skin and the more likely the blemish will scar. It is very important to remind clients not to squeeze. When pimples are pinched or squeezed, the infectious material can spread. Unless proper treatment is given, this can cause more blemishes and scarring.