What is acne?
Acne is a condition characterized by inflamed or infected sebaceous glands. These often erupt as red pimples (also called zits) on the skin. It is very common in teenagers, but some also continue to experience it later in life.
What causes acne?
A slow-growing bacteria called Propionibacterium acnes (P. acnes) (Kirschbaum and Kligman 1) has been shown to be involved in the development of acne.
Removing the infection using anti-bacterial agents is thought to be an important part of acne treatment.
Some feel that the main cause of acne is the accumulation of oil and sebum, and that the skin finds it difficult to metabolize the toxins produced in association with the increased production of sebum and oil. This inability to remove the serum and oils helps cause the bacterial infections, which in turn lead to inflammation.
Sources:
1 http://www.ncbi.nlm.nih.gov/pubmed/14071457