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What Causes Acne?

Here’s a quick quiz for you and your teen about the causes of acne.

What’s responsible for your teen’s acne?

  1. Forgetting to wash their face
  2. Regularly eating French fries
  3. Using make-up
  4. All of the above
  5. None of the above. It is a misconception that teens’ behavior determines whether or not they will get acne.

The right answer is E). Nothing your teen did was responsible for them getting acne.

So, what are the causes of acne? While there are no easy answers, there’s growing evidence that the main culprit is genetics3-5: A person’s genetics significantly influence the severity of their acne, and even the likelihood of developing acne at all. Each person’s innate immune system also plays a significant role, and the way the body reacts to some acne-causing bacteria is also very much out of your teen’s control.

Who develops acne?

Acne is the most common skin condition for teens and young adults, affecting at least 85% of people aged 12 to 25 years old.1 People are more likely to develop severe acne if one or both of their parents had it. Although acne can show up for the first time at any age, it is most common in teenagers.2

What causes acne?

  • Genetics3-5Evidence shows that a person’s genetic makeup can influence their likelihood of getting acne. Genetics can also play a role in how severe acne will become. Genetics affect many of the traditional causes of acne, including:
  • Oil-producing pores – Sometimes, hair follicles, aka “pores,” collect excess skin cells at the surface which then clogs follicles. This leads to overactive production from an oily gland that releases “skin oil,” called sebum, that gets trapped in the pores. When these pores get infected, it results in outbreaks of acne.6
  • Hormones – This is one reason that acne is more common in teenagers. During puberty, the hormones, called androgens, that are produced increase the size of the oil gland in a person’s skin. When these glands get bigger, they start producing more oil, which clogs pores and leads to breakouts.2
  • Inflammation – There are millions of bacteria present on our skin, most of which benefit us. However, there are some bacteria and bacterial strains that contribute to acne formation. One of these, called Cutibacterium acnes (C. acnes), has certain strains that can live in your pores and interact with the innate immune system in at least four different ways.7 Once there, C. acnes will release certain compounds that break down the walls of the pores, causing the pores to rupture. The immune system will respond to the C. acnes in the pores, and this combined with the ruptured pores will lead to inflammation and breakouts.6

What doesn’t cause acne but can make it worse?

  • Diet – The role of diet in acne remains controversial, but one thing that researchers agree on: a poor diet is NOT the cause of acne. However, a diet high in sugar, fats, and dairy may make a breakout worse by contributing to inflammation.8,9 Eating a nutritious diet high in fresh fruits and vegetables may help reduce inflammation.9
  • Stress – While stress does not cause acne, it may make existing acne worse and lead to flare-ups. When people are stressed, their bodies produce hormones that increase the size of the oil glands in their skin. These are the same types of hormones that are produced in larger amounts when a child enters puberty.10

A word about blackheads:

Blackheads are not caused by dirt. The dark color of blackheads are caused by a build-up of dead skin cells that collect in the pores. When these dead cells become trapped, they start to break down and darken, giving blackheads their dark appearance and name.11

It is important to understand that scientists are continually making new discoveries about the causes of acne, and why teens are affected the most. It’s also important to know that teens are not to blame for their acne.


1. Zaenglein AL, Thiboutot DM. Acne vulgaris. In: Bolognia JL, et al, eds. Dermatology. 4th edition. Mosby Elsevier; 2018:588-592.

2. AAD. Acne: Who gets and causes. Accessed March 8, 2022.

3. Mitchell BL, Saklatvala JR, Dand N, et al. Genome-wide association meta-analysis identifies 29 new acne susceptibility loci. Nat Commun. 2022;13(1):702. doi:10.1038/s41467-022-28252-5

4. Petridis C, Navarini AA, Dand N, et al. Genome-wide meta-analysis implicates mediators of hair follicle development and morphogenesis in risk for severe acne. Nat Commun. 2018;9(1):5075. doi:10.1038/s41467-018-07459-5

5. Bataille V, Snieder H, MacGregor AJ, Sasieni P, Spector TD. The influence of genetics and environmental factors in the pathogenesis of acne: a twin study of acne in women. J Invest Dermatol. 2002;119(6):1317-1322. doi:10.1046/j.1523-1747.2002.19621.x

6. Kern D. Do different strains of acne bacteria affect acne differently? Updated April 25, 2020. Accessed March 8, 2022.

7. Firlej E, Kowalska W, Szymaszek K, Roliński J, Bartosińska J. The role of skin immune system in acne. J Clin Med. 2022;11(6). doi:10.3390/jcm11061579

8. AAD. Can the right diet get rid of acne? Accessed March 9, 2022.,to%20a%20low%2Dglycemic%20diet

9. Cleveland Clinic. Acne. Accessed March 9, 2022.

10. AAD. Adult Acne. Accessed March 9, 2022.,which%20can%20lead%20to%20acne

11. Brennan D. What happens if you don’t remove blackheads? Published February 17, 2021. Accessed March 9, 2022.

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