If there’s one thing we know about acne, it is that it is not caused by just one single thing. Acne, like most diseases, is multifactorial in nature. Its development is the fruit of complex interactions between the skin we’re born with, the way we treat it, and the environment it’s exposed to.
We know a lot about the first two factors, but how about the third? It seems reasonable to think that environmental factors like the quality of air, the temperature, or the humidity have an effect on the skin, but the details are fuzzy.
Let’s take a walk-through about what science has uncovered about the relationship between our skin and our environment, and what we can do to minimize its acne-inducing effects.
Air pollution
If you’ve ever noticed that your acne improved when you get away from the city, you might have thought it was because of the cleaner air. And you might just be on to something there.
There have only been a few studies done on it, but one similarity among them is the correlation between acne and high levels of particulate matter and nitrogen oxide. These substances are not supposed to be found in detectable amounts in the earth’s atmosphere, but their levels rise because of large-scale human activity.
Nitrogen dioxide is a byproduct from industrial processes like combustion and exhaust, as well as agricultural processes like mass production of feeds. Particulate matter are minute bits of solids or droplets of liquid that are suspended in the air, usually coming from factories emission and traffic. They are called PM2.5 and PM10 for their diameter in micrometers. For reference, a single strand of human hair has a diameter of 70 micrometers, so just imagine how small the particulates you inhale are.
We may not see particulate matter or nitrogen oxide, but the effect it has on our bodies is real. Research is rife with proof connecting these air pollutants to lung disease, but we are just at the tip of the iceberg when it comes to understanding its effect on the skin.
Not surprisingly, most of the research in this department has been focused in Beijing, China. In a city where the smog can get so thick that its residents can’t see the blue of the sky, it’s easy to study the effect of extremely high levels of air pollution on the body.
After logging in patient records and monitoring air pollution for two years, a study found that the number of people visiting dermatologists to complain about acne rose whenever the levels of PM2.5, PM10, and nitrogen dioxide rose. Another study found that sebum levels and number of acne lesions increased whenever the ambient levels of the same air pollutants increased.
The details of how this happens are still fuzzy, but scientists hypothesize that air pollutants trigger inflammatory cascades and help strip the skin of its protective function. “Inflammatory cascades” may sound fancy, but it basically means that ambient pollution triggers our skin to react with redness, swelling, and pain. And you know what that means: zits.
These tiny particles are associated with increased oiliness, as well as harmful changes in the composition of our facial sebum. Squalene and linoleic acid are typically found in healthy skin, but under polluted conditions, oxidation occurs. The products of this process are irritating to the skin and have long been associated with breakouts. Prolonged exposure to air pollutants also depletes our store of antioxidants like Vitamin C and E, which not only compromises our skin’s ability to protect us, but also results in a dull, tired, less supple complexion.
Don’t forget that certain air pollutants can create holes in our earth’s ozone layer, allowing more UV rays from the sun to enter the atmosphere. The effects of UV light on the skin is still under debate. On the one hand, it is associated with photodamage, sunburn, and oxidative stress that makes skin look aged. On the other hand, the bactericidal qualities of UV rays can control the population of acne-causing bacteria on the skin.
It is worth noting that not all air pollutants appear to be associated with skin problems. In fact, some studies found that an increase in sulfur dioxide, a gas that comes from burning fossil fuels, is associated with less oil production and less acne lesions. This only goes to show that there is still a lot we do not know about how ambient pollution affects our skin.
Weather and Seasons
As the weather and seasons change, so does the humidity and temperature around us. It not only dictates our change in wardrobe, but also, apparently, the condition of our skin.
But our experiences vary. A study found that 80% of acne patients said they noticed more frequent and severe breakouts during the summer months. Interestingly, 64% felt that winter had no effect on their acne. However, another study graded patients on the severity of their acne and found that there were significantly more acne patients with worsened lesions during winter than any other season. So what’s worse: hot and humid, or cold and dry?
The short answer is neither. A study found that the forehead sebum increased by 10% with every 1oC change in temperature. Heat and humidity cause sweating, which makes our skin a great breeding spot for microorganisms that cause infection and irritation. It’s second nature for us to wipe sweat off, which means an increased incidence of us rubbing our faces. And we know that mechanical friction is one reason behind acne exacerbation.
On the other hand, cold temperatures can also increase oiliness by causing the skin to overcompensate for how dry the environment has become. Hand creams are heaven-sent during the winter months, but if you touch your skin with the wrong product, it could cause sensitive skin to break out. In an attempt to keep your skin from cracking, you might be using products that are much too greasy for your skin type.
We may never get a definitive answer about which season or type of weather conditions are likely to worsen acne. A lot of it has to do with individual differences in our skin and the habits that we adopt when environmental factors change.
What We Can Do
If acne can be exacerbated by something as out-of-our-control as air pollution or the seasons, then you might feel resigned to the fact that you’ll just keep getting pimples forever. But you do have the power to protect your skin against its impacts.
Eating food rich in antioxidants can help counter the harmful effects air pollutants have on your skin. By strengthening your skin’s barrier function and helping it cope with environmental stress, you can have healthier and more supple skin.
Using sun protection will also help minimize the effects of UV rays on your skin. Just make sure to pick one that is oil-free and non-comedogenic so it does the job without causing you to break out.
Adjusting your skincare when there are big changes in temperature and humidity can also help keep acne at bay. Consult your dermatologist on the best course of action given your skin’s reaction to weather and seasonal changes.
Acne may be caused by different factors, but the effect of each one can be mitigated by a corresponding intervention. By learning more about acne, observing your skin as the environment changes, and adjusting your skincare and habits accordingly, you can seize control of your treatment and achieve healthy, clear skin.
This content is for general information only and is not a substitute for medical advice.
Resources:
Liu, W., Pan, X., Vierkötter, A., Guo, Q., Wang, X., Wang, Q., Seité, S., Moyal, D., Schikowski, T., & Krutmann, J. (2018). A Time-Series Study of the Effect of Air Pollution on Outpatient Visits for Acne Vulgaris in Beijing. Skin pharmacology and physiology, 31(2), 107–113. https://doi.org/10.1159/000484482
Krutmann, J., Moyal, D., Liu, W., Kandahari, S., Lee, G. S., Nopadon, N., Xiang, L. F., & Seité, S. (2017). Pollution and acne: is there a link?. Clinical, cosmetic and investigational dermatology, 10, 199–204. https://doi.org/10.2147/CCID.S131323
Pascoe, V. L., & Kimball, A. B. (2015). Seasonal variation of acne and psoriasis: A 3-year study using the Physician Global Assessment severity scale. Journal of the American Academy of Dermatology, 73(3), 523–525. https://doi.org/10.1016/j.jaad.2015.06.001
Patra, V., Byrne, S. N., & Wolf, P. (2016). The Skin Microbiome: Is It Affected by UV-induced Immune Suppression?. Frontiers in microbiology, 7, 1235. https://doi.org/10.3389/fmicb.2016.01235
Sardana, K., Sharma, R. C., & Sarkar, R. (2002). Seasonal variation in acne vulgaris--myth or reality. The Journal of dermatology, 29(8), 484–488. https://doi.org/10.1111/j.1346-8138.2002.tb00313.x
Zegarska, B., Pietkun, K., Zegarski, W., Bolibok, P., Wiśniewski, M., Roszek, K., Czarnecka, J., & Nowacki, M. (2017). Air pollution, UV irradiation and skin carcinogenesis: what we know, where we stand and what is likely to happen in the future?. Postepy dermatologii i alergologii, 34(1), 6–14. https://doi.org/10.5114/ada.2017.65616
