Publisher's Synopsis
Acne affects between 50-80% of teenagers and young adults. It is a disorder of the pilosebaceous unit (hair follicle and associated oil gland). Factors that contribute to acne formation include increased sebum (a substance made up of oil and wax that functions to protect the skin), increased build-up of material in the hair follicle, increased levels of Propionibacterium acnes (a bacteria that is commonly present on the skin in low numbers), and inflammation. Clinically, there are three categories of acne including comedonal (whiteheads and blackheads), inflammatory (red bumps), and nodular (large, painful cysts). Hormones signal oil glands in the skin to increase their production of sebum. A plug of sebum and keratin (a protein that helps maintain the structure of the skin, hair, and nails) forms and blocks the opening of the hair follicle creating whiteheads and blackheads. The increased sebum supports increased concentrations of P. acnes. This leads to further blockage of the hair follicle opening and to increased inflammation. Ultimately the hair follicle can rupture, resulting in large, painful nodules. Insulin also contributes to the formation of acne. Insulin and insulin-like growth factor act by directly increasing the activity of the oil gland, as well as by indirectly increasing the levels of other hormones that stimulate the oil gland.
