In the slim chance you haven’t already heard, acne isn’t only a teenager’s problem. The American Academy of Dermatology (AAD) reported adults in their 20s, 30s, 40s, even 50s can develop the common skin condition, which is to say they grow up to continually struggle with pimples, deep lumps like cysts, black- and whiteheads.

Acne isn’t limited to a person’s face either. According to the AAD, nearly 85 percent of people will experience acne on their face, chest, and back at some point in their life. And if a person’s preferred treatment is still to pop or squeeze a pimple, they’ll increase the likelihood of acne-related scarring.

The age-old advice when it comes to reducing acne is to pay special mind to oily, bacteria-ridden skin — growth of the bacteria P. acnes is a leading cause of the condition — as well as saying no to stress and eating healthier foods. Think less dairy, more vitamin E and antioxidants.

There are other commonly-touted natural solutions for acne, such as tea tree oil, increased daily water intake, and cooking more with the spice turmeric. And of course, there are medications your dermatologist can prescribe.

However, the Food and Drug Administration recently announced that so many of the popular acne treatment medications can cause rare, potentially fatal allergic reactions. So if following all this advice (pre-meds) doesn’t do much for your skin, here are the more surprising sources of acne.

Pillow Cases

Pillow cases get zero afterthought. You put one on, flip it over when it's not cool, rinse, repeat. Yet they actually double as a sponge for your skin products, sweat, drool, and hair products, Allison Tray, owner of the Tres Belle Spa in Brookly, N.Y., told Medical Daily in an email. So if you’re not in the habit of changing it, all that good harmful residue piles up. Add the pet that likes to curl up to you next at night, and it’s no surprise your acne symptoms aren't improving.

Tray’s solution? Try every few days to create a clean pillow surface. Flip it over, turn it inside out and change it, giving the old one a much-needed wash.

Cell Phones

Been taking a lot of calls? Frequently pressing your check and chin against screens exacerbates pimple-producing oils, Dr. Eric Schweiger, a dermatologist and clinical instructor of dermatology at Mount Sinai Medical Center in New York City, told Everyday Health.

"It's called 'acne mechanica,'” he said. “It happens to violinists around the chin and football players with the chin strap — it's [caused by] not letting the pores breathe, and the repetitive motion causes friction. Now we're seeing it with cellphones."

Regularly cleaning your screen will lessen these acne-causing oils. Or, consider investing in a Bluetooth device for hands-free, thus cheek-free, conversations.

Making Out

This is one of those causes that sounds weird, but they make total sense when you stop to think about it. Officially, it’s known as “consort acne,” and it results from your partner’s oily cosmetics, like hair gel. Sharing towels and pillow cases that haven’t been cleaned in a while also increases exposure, thus breakouts.

Switching to oil-free, non-comedogenic products, as suggested by the AAD, reduces risk for consort acne, as well as keeping your own towel stash. Comedogenic is just a fancy way of describing the moisturizers and other cosmetics made from acne-causing formulas.

Sugar-Induced Inflammation

Maintaing a poor diet impacts skin, for sure, but none as much as processed, refined, and sugary foods. These do not digest easily in the human body and can actually stay lodged in your gut for an extended period of time due to lack of fiber, which helps to move it out, Dr. Roshini Raj, gastroenterologist, celebrity doctor and founder of TULA skin care, told Medical Daily in an email. “This, in turn, can cause inflammation that affects your healthy gut balance and thus, your overall digestion and appearance of your skin,” she said.

Raj recommends avoiding processed foods when possible, in addition to punching up probiotic intake. “Named as a new beauty breakthrough by the AAD, probiotics have been shown to help with acne, calm inflammation, and decrease skin sensitivity and redness,” she said. “By altering the permeability of intestinal walls and acting as a sealed barrier, they prevent certain molecules that may lead to inflammation, which in turn can trigger acne or rosacea, from entering the bloodstream.”

Hormones

“I think most people don't realize the strong hormonal component of acne in women, particularly adult women, myself included,” Dr. Rebecca Kazin, Medical Director of the Johns Hopkins Dermatology and Cosmetic Center, told Medical Daily in an email.

When appropriate, Kazin loves to use spironolactone. According to her, it works to block androgen from binding to the sebaceous, or oil-producing, glands. Keep in mind that this particular medicine requires close monitoring and should not be used in women who are currently on birth control.

No Air

Or at least, not great air. “If you don’t properly care for your air filtration system in your home, the dust, dirt, and bacteria in the air may become stagnant and exacerbate or cause your skin problems,” Scott Vincent-Borba, beauty expert and author of Skintervention, told Medical Daily in an email.

Changing the filter in your hose every 90 days can ensure proper air filtration. Bonus: Proper air circulation mitigates sinus issues and betters overall breathing.

Clothes

If you're not regularly washing your pillow cases or towels, there's a good chance you let a few days go by before washing your everyday clothes. However, if you have back acne or other skin challenges in places where the pre-worn clothing is touching, the dirty residue may be what’s causing it, Borba said.

"The dirt and bacteria on your body will naturally build up each day and transfer onto the material of the clothes you wear and get trapped in the fibers," he said. "So here’s my advice: if you have a serious skin problems, or very sensitive skin, you need to come to terms with the maximum number of times you can wear something to keep your body clear of acne is twice."