Background

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 Cutibacterium 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 including insulin-like growth factor and androgens.

There are many factors to take into account when deciding on a treatment plan: the type of acne, the severity of acne, whether there is scarring, what has been tried in the past, and the psychological impact should all be assessed.  In girls and women, information about menstrual history (specifically regularity, duration, and quantity of bleeding) and signs of hormonal abnormalities (excessive facial hair, insulin resistance) can also be helpful.

Treatment

Skin Care

The first step to managing acne is to adhere to gentle skin care practices.  The skin should be rinsed gently with warm water once or twice a day.  Washcloths or other abrasive materials should be avoided, and only gentle, nonsoap-based cleansers should be used.  Detergent-based soaps, toners, and astringents further dry and irritate the skin.  While they do remove oil and sebum from the surface of the skin, they do not alter sebum production within the oil gland.  Ultimately, overly dry skin signals the pilosebaceous units to make more oil in order to adequately protect the skin.  Moisturizers can help acne, but it is important to make sure any moisturizers or cosmetics are not oil based and are labeled noncomedogenic.