The list of acne triggers is lengthy and narrowing it down to determine exactly what’s causing your breakouts can be tricky. But considering where your blemishes tend to pop up can offer some helpful clues as to what factors may be at play. In short, it’s important to look at not only the types of pimples, but also where on the face—or body—they occur. “It’s not always random,” says James Del Rosso D.O., adjunct clinical professor of dermatology at Touro University Nevada in Henderson, NV and an Acne Store advisory board member. Ahead, Del Rosso explains more about why the ‘where’ matters.

Q: Why do we only get pimples on the face, chest, or back, and not on other areas, like the hands or soles of the feet?

A: The concentration of acne predominantly on the face and trunk of the body has to do with where we have pilosebaceous units, which are pores that contain hair and oil glands. Each is made up of the sebaceous gland, hair follicle, and hair strand, and are connected under a pore on the surface of the skin. Problems occur when those follicles get blocked by an unexplained buildup of cells that line the pore and then trap excess oil and bacteria. The density of these pilosebaceous units is highest on the face, but also very high on the upper back, chest, and shoulders. This is why these areas tend to be prone to breakouts.

Q: What does acne on the chin mean?

A: Adult acne can present all over, but women in their 20s, 30s, and 40s often have acne around their jawline, lower face, and neck. One out of four also experiences much deeper blemishes. The reason why this happens in the lower face area has to do with the interaction with the hormones and the follicles in those particular areas. It could be that the oil glands are different in these areas, but that hasn’t been scientifically proven.

It’s worth pointing out that perioral acne around the chin and mouth also exists, though it can easily be mistaken for another condition that’s common in young women known as perioral dermatitis. This latter condition manifests as little pink bumps that run together and mimics chin acne, and often gets mistreated as such. However, many acne medications will only exacerbate perioral dermatitis, so it’s important to make sure the condition is diagnosed properly.

"Women in their 20s, 30s, and 40s often have acne around their jawline, lower face, and neck."

Q: Why is there acne on my forehead?

A: There are a few things I think about when I see acne on the forehead. It could be frictional acne, caused by the constant rubbing that occurs from wearing a hat or cap all the time. Secondly, I wonder what type of hair products the patient’s using. Gels or thick styling products can leave behind residue on the forehead, along the hairline, or even the side of the neck. These are products meant for your hair, not for your skin, so that can be a contributing factor to pimples on your forehead. I always suggest that people wash their hands and face after putting products in their hair. 

Q: Why am I breaking out on my cheeks?

A: It’s very hard to say specifically what’s going on with cheek acne. The cheeks are very rich in sebaceous glands, as is the central part of the face in general. We know that people with acne on the cheeks tend to also have larger sebaceous glands than people that don’t. Some people are also simply born with larger pores, which can fill up with sebum and look like a black dot. This often happens on the nose as well.

Q: And what about if someone has body acne, more specifically on the chest and back?

A:  It’s very uncommon for someone to have acne on their chest or back, called truncal acne, without also having facial acne. I spearheaded a study that found that only about 3% of individuals who had acne on their back or chest didn’t have it on their face. [1] In short, if you have acne on your face it’s likely that you may have it on your body as well. Again, the areas of the body we’re talking about here have higher concentrations of those pilosebaceous units. And for the back, just like with the forehead, hair products can play a role, specifically heavier conditioners and products that get rinsed out of the hair but still leave behind residue on the upper back.

References:
[1]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6122512/