This page is part of Toronto dermatologist Dr. Michelle Levy’s dermatology library. Please read our disclaimer for more information.

Acne, (also known as acne vulgaris)  is an extremely common skin condition that affects up to 95% of people at some point in their lives.  Acne can have profound psychological effects on individuals and patients report effects on their self-esteem and outlook.

What Causes Acne?

The three most important factors that contribute to the development of acne are hormones, bacteria and sebum (oil).  Acne treatments tend to target one or more of these factors.  

  1. "Sticky" skin cells accumulate in the opening of the hair follicle instead of being shed. This blocks the pore, creating a small "blackhead" or "whitehead".

  2. Hormones act on oil glands associated with the hair follicle to produce more sebum, or oil.

  3. Oil and dead skin cells accumulate in the hair follicle, leading to increased pressure.

  4. Bacteria known as p. acnes proliferate in the hair follicle, leading to inflammation.

  5. Eventually, the wall of the blackhead or whitehead ruptures, leading to inflammation and visible pimples or cysts.

What are the Different Types of Acne Spots and Why Does it Matter?

There are four main types of acne spots:

  1. Comedones. Formed when hair follicles that have been blocked by dead skin cells and oil. They can be white or black depending on whether they are closed or open ("whiteheads" or "blackheads")

  2. Papules. Raised red bumps that occur when the blocked pores become inflamed.

  3. Pustules. Raised red bumps with pus in them.

  4. Nodules or Cysts: Larger cystic red bumps that are deep, painful, and more likely to lead to scarring.

Not all patients will get all four of the classic acne spots.  Some patients will only get blackheads, while others will get blackheads, papules and cysts. The types of spots determine the best choice of treatment.  Acne treatment isn't one size fits all and should be tailored based on the severity of the acne, the types of acne spots, and the patient's preferences and goals.

Do Only Teenagers get Acne?

No.  Acne occurs in individuals of all age groups.  35% of women in their 30s and 26% of women in their 40s report having acne (the corresponding numbers for men are 20% and 12%).  Adult acne in women is frequently "hormonal".  It often flares around the time of one's menstrual cycle and may be more likely to improve with hormonal therapies.

How is Acne Treated?

There are many different ways to treat acne.  Mild acne can often be treated with topical medicated creams or gels, while more severe or extensive acne is usually treated with a medication that is taken by mouth.  Some of the common ways in which acne is treated are:

  1. Topical treatments such as benzoyl peroxide, vitamin A acid, topical antibiotics or dapsone gel

  2. Oral antibiotics such as doxycycline or tetracycline

  3. Hormonal therapies such as birth control pills or spironolactone

  4. Isotretinoin

  5. Procedures such as chemical peels, photodynamic therapy or extractions/acne surgery

For Dr. Levy's blog post on the treatment of adult acne please click here.

Does what I Eat Influence my Acne?

This is somewhat controversial.    Observational studies have also found that milk intake (especially skim milk) is positively associated with acne prevalence and severity.  Other studies have linked acne to a high-glycermic diet.   Most experts agree that dietary factors are rarely the primary cause of acne, but may contribute to its severity.  Please avoid making any drastic changes to your diet without medical supervision.

What are Some Skin Care Tips for People with Acne?

  1. Make sure you use only oil-free or non-comedogenic products on your skin

  2. Wash your face 1-2 times per day with a gentle cleanser. Remove your make-up in the evenings

  3. Wash your hair daily

  4. Do NOT pick at your pimples

  5. If you have mild acne and wish to try an over-the-counter product, choose one with benzoyl peroxide in it

  6. If you have acne that is causing scarring or has not responded to over-the-counter treatments consider seeing a dermatologist for advice

What About Scarring?

Acne can lead to lifelong scarring.  If you are developing acne scarring, please consider seeing a dermatologist to discuss acne treatment in order to prevent further scarring.  Acne scarring treatments are reviewed here.