What is Acne?
Acne occurs most frequently at puberty, when the sebaceous glands and keratinocytes are stimulated by pubertal hormones to increase the rate of production of sebum and keratin respectively. The excess keratin cells can then quickly block the pores of the sebaceous glands, trapping the sebum below, which then solidifies. This creates an ideal breeding environment for bacteria which normally live harmlessly on the skin, especially the bacteria associated with acne, called Propionibacterium acnes (or P. acnes). This bacterium thrives in the anaerobic environment generated by the clogged pore, and by feeding off sebum. The metabolic by-products of P. acnes inflame and destroy the wall of the hair follicles, allowing the inflammation to spread deeper into the tissues, causing infected spots which either erupt onto the skin or form painful cysts trapped below the surface. Acne also occurs in adulthood, often due to imbalances in the androgen hormones, especially testosterone and DHEA, or fro...