It’s not the pizza, say dermatologists. What really causes acne breakouts

Skin care influencer Dr. Stefanie Stockhamer says her experiences with acne began in adolescence. At the time, her breakouts were mild and relatively within control. 

It wasn’t until she began medical school, however, that Stockhamer’s acne grew worse. 

“It was my mid-20s when it got a lot worse, significantly worse than it’s ever been in my adolescence,” said Stockhamer, a 26-year-old family medicine resident at the University of Rochester, originally from Toronto. 

“And it’s still something that I do struggle with today.”

As common as acne is, experts say there are some popular misconceptions about its causes. Research suggests diet and poor hygiene are not the clear culprits, but rather a multitude of factors are at play, including genetics, hormonal changes — and stress. 

Zits, blackheads and whiteheads are all forms of acne

Acne is a skin condition characterized by pores clogged by dead skin cells and oil, called sebum. Bacteria present on everyone’s skin is also involved in the development of acne breakouts. 

“Because sebum is an awesome thing to eat and the hair follicles are an awesome place to live, you have bacterial overgrowth and that altogether causes inflammation,” said Dr. Yuka Asai, chair of Queen’s University’s division of dermatology in Kingston, Ont.

Acne can present as whiteheads and blackheads — known as comedones — as well as pimples and pustules referred to as papular acne, but more commonly called zits. 

Acne sometimes presents as deeper lesions like cysts or nodular cysts that can result in scarring, according to Dr. Kerri Purdy, head of Dalhousie University’s department of dermatology in Halifax.

“Many people have a combination of all those types of acne,” Purdy told Dr. Brian Goldman, host of The Dose. 

The Canadian Dermatology Association (CDA) estimates that patients aged between 12 and 24 make up more than 80 per cent of people living with acne in Canada. 

Nonetheless, acne affects people of all ages. Estimates from the Acne and Rosacea Society of Canada and the Canadian Skin Patient Alliance suggest it affects roughly 20 per cent of all Canadians. 

Women make up roughly 75 per cent of all adult acne patients, according to the CDA. 

Eating pizza won’t make acne worse

Despite the stereotype of the acne-riddled high schooler who worsens their skin condition by eating greasy foods and failing to properly wash their face, dermatologists like Dr. Monica Li say it’s not entirely clear why some people get one type of acne and not another. 

“The actual exact causes are probably not fully known,” said Li, who is a clinical assistant professor at the University of British Columbia’s department of dermatology and skin science.

“We can identify the pathways or what we call pathogenic factors, and we do know they don’t occur in isolation.”

Purdy says unhealthy dietary choices, like eating too much pizza or chocolate, aren’t necessarily responsible for causing acne in the first place. 

She adds that she’s not convinced by some studies that show a connection between high dairy and carbohydrate intake and an increased risk of acne. 

“There’s never really been any convincing evidence to suggest that the diet plays a role,” she said. 

However, Purdy says there are a number of factors shown to increase the risk of acne. 

“We know that there’s a genetic component,” she said. “We know that there’s a hormonal influence.”

A 2023 paper published in the International Journal of General Medicine concluded that “both genetics and the environment play a significant role” in the development of acne, while other papers have drawn a link between hormonal changes and acne. 

Using excessively oily skin care products can also increase the risk of acne. Certain medications — including chemotherapy medication and steroids — are also known to cause acne. 

“Then sometimes people get increased acne in places like their chest and back, if they’re very sweaty and they’re wearing sweaty clothes,” said Purdy. 

“Those things can make it worse.”

However, poor hygiene won’t necessarily cause acne, Purdy says. 

“But if you have acne, having your hygiene as good as possible and using bland products that will help to maintain your skin barrier — that’s really important,” she said. 

Gently wash your face, talk to a doctor to treat acne

The first step in treating acne, Asai says, is identifying the kind of acne patients are experiencing. Next is identifying the patient’s skin type. 

“For example, people who are known to have dry skin and eczema tend to have very sensitive skin,” said Asai. 

“And so trying to balance whether or not they have sensitive and dry and irritable skin with the products that we need to use … is key.”

Asai also tries to identify any genetic predispositions to acne — if a patient’s parents had acne, for example — as well as if a patient is going through a period of hormonal change, like puberty, perimenopause or menopause. 

She also identifies patient’s lifestyle choices when helping tailor acne treatments.

“There are some people who enjoy having a 20-step process of skin care,” she said, adding that’s not necessary. 

Stockhamer, the University of Rochester family medicine resident and skin care influencer, says a basic, three- or four-step routine is often enough to treat her acne. 

She recommends a gentle facial cleanser, an acne-directed treatment, appropriate moisturizer for the right skin type, as well as sunscreen. 

Purdy says the first line of acne treatments are topical creams and gels that have vitamin A or a retinoid. 

Topical antibiotics, as well as topical treatments like azelaic acid, topical dapsone and topical clascoterone, are other first-line treatments recommended by Purdy. 

“If people have mild acne … they can be very effective,” she said, adding that patients need to use treatments for eight to 12 weeks to really see positive effects.

“Once they start seeing improvement, people are pretty good about using [these treatments], but you really need to get them into that improvement period, which is not immediate.”

Purdy says oral antibiotics, as well as oral contraceptives and anti-androgen medications for women, are medication options. 

Androgens are sex hormones that produce male characteristics.

Isotretinoin remains highly effective

Finally, Purdy says that isotretinoin — best-known when sold under the Accutane brand — is a “very effective medical treatment” for severe acne or for milder acne that hasn’t responded to other treatments.

“In terms of efficacy … if you complete a full course, the chance that your acne is gone in the long term is about 75 per cent, sometimes a bit higher,” she said. 

“Sometimes it does come back, but there’s no limit to the number of times you can take that medication if needed.”

Despite isotretinoin’s effectiveness, Purdy says there are known side effects, including dry lips and sun sensitivity.

Some research also suggests Isotretinoin “causes birth defects in up to 35% or more of infants who are exposed during pregnancy.”

Additionally, social media sometimes suggests an increased link between isotretinoin and depression and suicidal ideation. 

Purdy says those risks are unfounded. 

“Occasionally, people will say I don’t feel myself on this medication,” she said. 

“In that case, we decrease or stop it. Everybody’s different, but from a population level … really nothing to suggest that it is related.”