However, during puberty these cells are shed more rapidly and tend to stick together. The clogged follicle becomes a breeding ground for bacteria. One type of bacteria specifically involved is Propionibacterium acnes or P. acnes for short. P. acnes ingests sebum and is a normal resident on skin even in people who don't have acne. However, when the sebaceous gland gets clogged, and sebum builds up inside the follicle, P. acnes multiplies rapidly.
Chemicals produced by the bacteria can cause inflammation in the the follicle and surrounding skin.
Roche Laboratories Inc. American Academy of Dermatology, 2000. All rights reserved. Produced by NetOn-Line Services .