Skin School: What causes acne and how do you treat it?

woman looking to the right with acne

There are few things that are quite as frustrating – not to mention debilitating to your self-esteem – as waking up with breakouts or struggling with ongoing acne, whether it’s mild or severe. According to the NHS, a huge 95% of people aged 11 to 30 years old experience acne, and studies show that it is becoming more prevalent among adults – particularly women.

Whether you’re struggling with random breakouts, or have been combating acne since your teenage years, finding the right treatment can feel overwhelming – a trial and error approach leads us to feel deflated as our skin stays the same, or gets even worse, and in the meantime we’ve spent way too much money on sub-par results. This guide is designed to arm you with the knowledge you need to take the right step forward. 

At Kate Kerr London, acne is one of our favourite skin conditions to treat as the transformation that we can achieve within the skin is amazing, and we just love seeing our clients’ confidence soar – because the results aren’t just physically transformative, they’re psychologically transformative, too.

We not only help to clear the skin, but also help to improve the skin’s quality and glow, better than it’s ever been before. Here’s everything you need to know about preventing and treating acne…

Graphic showing different types of acne

What is acne?

Acne is a common skin condition that involves the hair follicle and its associated sebaceous (oil) gland. It’s commonly characterised by papules that are referred to as ‘spots’. The spots can range from:

  • Comedones (also known as blackheads & whiteheads), which are often mild to inflamed.
    • Blackheads are open comedones, which means they are open at the surface of your skin. Oxygen in the air oxidises the dead skin cells and sebum within the pore, leading to a darker appearance.
    • Whiteheads, on the other hand, are closed comedones and form as raised bumps under the surface of your skin and remain skin-coloured. People often mistake the name ‘whitehead’ for spots with a pustular top, but this is a misconception.
  • Pus-filled lesions such as papules, pustules, nodules and cysts.
    • Papules are small to medium sized red, raised bumps, caused by inflamed or infected follicles.
    • Pustules are red spots that have a pustular head.
    • Nodules are solid, often painful, lumps that develop beneath the surface of the skin and can last for months.
    • Cysts are large bumps beneath the skin that contain pus and are often  angry and painful.

What symptoms might you experience with acne?

Acne can be found almost anywhere on your body, but most commonly can occur in areas with the most abundant oil glands, such as the:

  • Face and neck
  • Back
  • Shoulders
  • Chest

Spots and breakouts can give your skin a rough, uneven texture. You might also experience:

  • Skin discolouration, including dark patches or spots (post-inflammatory hyperpigmentation, also known as PIH) and redness
  • Swelling and inflammation
  • Pain and tenderness 
  • Scarring; both textural and discolouration 
Woman looking at the camera with acne

What causes acne?


Acne is caused by the activation of the skin’s sebaceous gland, leading to increased sebum production. Our skin naturally produces oil, but oil isn’t part of a healthy skin. Sebum production is something that’s leftover from the evolutionary process, but today its inflammatory effects cause more harm than good. 

When our hormones trigger excess oil production, our normal skin shedding slows down and the skin’s surface starts to thicken with accumulated cells. The combination of these factors causes an accumulation of dead skin cells and oil within the pore. 

This plug or blockage is known as a comedone. The acne bacteria, P.acnes, which is naturally present on the skin, builds up under the comedone causing inflammation which leads to the formation of papules, pustules or cysts. This inflammatory response on the skin becomes an immune response, leading to chronic breakouts. The increase of inflammation can also exacerbate skin conditions such as rosacea, hyperpigmentation and seborrheic dermatitis. 

It’s important when treating acne to address each of these four contributing factors – excess oil production, sluggish cell turnover, acne bacteria and inflammation – and not just the symptoms, which is sadly the goal for a lot of skin specialists, and even medical professionals. Some also believe that acne is an allergic reaction to sebum – this makes sense as there is a huge percentage of people with oily skin who don’t experience breakouts.

Incorrect product use

Aside from hormones, there are other factors that can kickstart this not-so-welcome process. One of the key causes is the incorrect use of skincare products, which leads to the skin’s function becoming impaired. 

The popularity of skincare on social media and growing beauty influencers has led to an influx of us going out and buying products that might not be right for our skin – many of us are essentially becoming our own chemist, which is fun, but can cause unwelcome issues with our skin. We’re also seeing surges in the popularity of items like facial oils and cleansing balms, which can actually lead to and exacerbate acne conditions. Fun fact: it is very rare to see these products in cosmeceutical or medical grade skincare brands – if they were truly beneficial to our skin health, they would be included!

For acne caused by incorrect product use, there is a simple solution – education on the correct skincare protocol. The skin can often be considerably improved simply by addressing this one thing.

Moisturisers are the most common culprit when it comes to product misuse. It’s the incorrect perception that everyone should use moisturiser daily – it’s been ingrained in us since we were young, but in fact just isn’t true. The skin has its own moisturising processes and the use of moisturiser, on anything other than a truly dry skin (you will have never suffered from breakouts before – even in your teenage years – and are likely to have had eczema) actually inhibits the skin’s natural hydration, thus in fact making the skin more dehydrated! When the skin is lacking in hydration it will counteract this by overproducing sebum, to try and trap in the water. The excess sebum can’t escape from the follicle onto the skin’s surface, due to the accumulation of skin cells and the skin being tight and dehydrated, which leads to congestion and breakouts. 

woman looking to the side

Less obvious causes of acne

There are lots of day-to-day activities that can cause breakouts and sometimes we don’t even know that we’re doing them. 

Touching our faces with dirty hands is a big one – think about the bacteria on an escalator handrail, for example, if you touch that and then your face, you can imagine the bacteria you’re transferring to your skin; this constant stimulation can also activate the sebaceous gland (that’s the gland responsible for producing oil). This bacteria causes oxidation in the skin and the activation of more inflammation. 

Another key cause can be exercising without removing your make-up or moisturiser. The sweat combined with the often comedogenic (aka pore-clogging) ingredients found in these formulas is a recipe for outbreaks.

In fact, the very type of exercise we choose can impact our likelihood of experiencing breakouts: intense exercise such as HIIT workouts can cause our cortisol to spike, activating the sebaceous gland, which increases oil production, leading to more breakouts. 

It’s best to limit HIIT workouts to two to three times per week, and be sure to have a rest day or two in between each session. Low-to-moderate exercise is beneficial as it can decrease cortisol levels from a busy, stressful life, which helps to improve our skin clarity. 

It’s also important to consider what you use on your face. A lot of primers and moisturisers contain waxes and oils to fill in supposed ‘flaws’ and create a smooth finish, but they also fill in pores! Cream blushes and the new trend of contouring can also lead to a line of spots in the application area due to congestion.

According to a 2021 review, certain foods or diets may also have an effect on acne – for example, consuming certain milk products, such as milk and ice cream, seems to worsen acne for some people. A diet high in glycemic index foods (such as carbohydrates and sugars) can also lead to inflammation and increased breakouts.

Who is more at risk of developing acne?

We still don’t know exactly why some people experience acne and others don’t, however, there are a number of risk factors that can contribute to and worsen acne, including: 

  • Hormonal changes due to puberty, pregnancy, perimenopause and the menopause
  • Polycystic ovarian syndrome (PCOS) and other endocrine conditions
  • Smoking cigarettes and recreational drug use
  • Poor sleep
  • Stress
  • Use of cleansers, creams, moisturisers, and other products that are oil-based or have high oil content
  • Certain medications, including lithium, some types of hormonal birth control, anticonvulsants, steroids and B12 injections
  • A family history of acne
  • Poor diet

We have the highest risk of developing acne during puberty. This is a time when our body undergoes huge hormonal changes, which trigger oil production, leading to an increased risk of acne. 

What do different spots mean?

I don’t believe that spots in different areas can be attributed to issues with certain organs within the body, however, there are a few factors that do lead to acne in particular areas. For example, on the chin or jawline, spots tend to be more hormonal and therefore are more common during the second half of the month of your menstrual cycle. 

On the cheeks, breakouts can be down to spread of bacteria from hands, phones or not changing your pillow cases frequently enough, while spots around the mouth can be caused by the residue from greasy or fatty foods, and even certain lipsticks or lip glosses. It can also be a result of make-up choices – for example, if you’re using cream or oil-based blush, or contour products. 

If you’re experiencing breakouts around the temples or hairline, look to your hair products, which could be the culprit, causing congestion. A lot of hair products are wax-based and the hair falling on the face can transfer this – also having oily hair can cause the sebum to travel, so it’s best to tie the hair back away from the face. 

The back and chest are areas where we have a higher number of oil glands and we tend to sweat more profusely here. Wearing materials that don’t quickly draw sweat away from the skin, such as cotton, can result in irritation, leading to outbreaks. Manmade fibres that are designed to wick the moisture away from the skin and be fast drying will help reduce this and are particularly important to wear during exercise. It’s also a good idea to cleanse with a salicylic acid-based cleanser straight after exercise, or anything that has caused you to get hot and sweaty. 

On the flip side, as with our face, it can be beneficial to allow sweat to flush the skin of cell debris and dead skin cells from within the pores. It’s important however that the skin is clean and makeup or moisturiser free, to allow this.

woman looking to the side with acne

Treatment for acne

The options for the treatment of acne depend on the severity. Those with cystic or nodular acne often require medical treatment; however, it’s not always necessary for mild-to-moderate conditions.

At Kate Kerr London, 70-80% of our patients suffer with varying degrees of acne, ranging from open and closed comedones only, to inflamed breakouts. We treat the skin using targeted cosmeceutical skincare and regular advanced facial treatments that yield brilliant results and make a huge improvement to our clients’ condition, as well as general skin health.


It’s often the direction of GPs to treat acne symptoms and not the root cause, thus never reaching a long-term cure. As clinical skin specialists, we look at the overall skin health, addressing every cell type within the skin to ensure it’s working optimally. A well-functioning skin is a skin free of skin conditions or disease – it’s also a skin that glows and ages gracefully. 

Acne can often feel tricky to navigate, as GPs don’t always have the answers as the depth of understanding and training isn’t the same as specialists in the field. Usually the first line of defence, if you’re visiting a GP, is antibiotics. These certainly have their place, but never on their own. 

Antibiotics will only treat the symptoms of acne and not all of the contributing factors, so once the course is finished, the acne returns. Antibiotics will target the inflammation and bacteria, but they won’t minimise the exacerbated oil production, or regulate skin cell turnover and dead skin cell accumulation – so whilst they can help with treating active papules and pustules, they won’t be able to tackle blackheads or bumpy skin, and the breakouts will usually come back when you’ve finished the course. Antibiotics can also have a detrimental effect on your gut health, so it’s important not to use them as a long-term solution. 

Topical medications, such as benzoyl peroxide, retin A and adapalene can target the remaining contributing factors towards acne, but compliance is key and it’s important that patients are aware of the expected side effects so they don’t give up. 

When it comes to treating the skin with medications, it’s all about the right combinations, and sadly, often the right combinations are not prescribed. Many medications are effective, but most target the symptoms, rather than the cause. Roaccutane addresses all four factors of acne, but it shouldn’t be taken lightly, so we recommend trying other solutions first, unless your breakouts are causing you scarring or significant psychological distress.

Regular clinical facials

For women, I recommend having a professional facial mid-skin cycle to counteract the flare ups that can occur just before your period. Having regular extractions with an expert to minimise blocked pores really helps to prevent breakouts – that’s because you can’t have an active acne spot without having had a blocked pore first. 

Blue LED light therapy incorporated into your treatment will also help to control the p.acnes bacteria and inflammation in order to prevent breakouts. At Kate Kerr London, we have a specific Clinical Clarifying Facial, which not only addresses the face, but can also be performed on the chest and back as well. 

It targets the four contributing factors of acne, to improve skin clarity, not only by helping to alleviate the visual symptoms such as inflammation and blemishes, but also by targeting the underlying cause to set you on a path to clearer, more radiant skin.

Aesthetic treatments

Our Advanced Skin Peels – particularly those containing salicylic acid at high concentrations – are very effective when it comes to improving acne breakouts, as well as fading post-inflammatory hyperpigmentation.

We use very prescriptive products to target all four contributing factors of acne – these help to not only treat, but prevent, future breakouts. They also help to improve the skin quality and improve acne scarring so the skin is slowing and radiant.

We also recommend Advanced Microneedling and Advanced Venus Viva Nano Fractional Radio Frequency if needed, once the skin has cleared, to treat any residual scarring. Combining these treatments with a course of peels can help to improve the skin’s texture and any discolouration. 

Using the right products

At Kate Kerr London, we place an emphasis on education so that our clients can make the right choices for the health of their skin. There are four key areas to focus on in order to keep spots at bay, these are; stimulating cell turnover, regulating oil flow, inhibiting bacteria and calming inflammation.

But beyond these contributing factors, we need to ensure the skin is functioning optimally as a whole and that the barrier is intact and resilient. A well-functioning skin is a healthy, clear skin. When it comes to products, there are some key ingredients that we recommend, which we’ve listed below, but we always treat the skin as a whole and prescribe a comprehensive regime in order to target all the key processes within the skin so that the skin glows, is calm and resilient, and ages beautifully – as well as targeting the acne itself.

We need to make sure the skin is hydrating itself, that it’s protected from the environment at all times and that the melanocytes are stabilised to prevent post-inflammatory hyperpigmentation (PIH) – that’s the pesky brown marks that hang around after a spot has healed and disappeared.  We may even need to activate the fibroblast (also known as the skin’s mother cell) to increase collagen production and improve scarring.

Woman looking to the side with acne on her cheek and forehead

When it comes to targeting the contributing factors of acne, Beta Hydroxy Acids (BHAs) such as salicylic acid, are brilliant as they increase cell turnover and exfoliate the skin’s surface and within the pore. They also have anti-inflammatory and anti-bacterial properties. I recommend the ZO Skin Health Oil Control Pads, which uses 2% salicylic acid, amongst other ingredients, to reduce sebum and exfoliate dead skin cells whilst deep-cleaning congested pores.

Vitamin A derivatives – or retinoids – are also key as they stimulate cell turnover. Retinols are great as they are also prevent premature ageing and with acne being more common in our thirties and even in our forties, we are looking for multi-active products to treat both acne and support healthy ageing simultaneously. 

We also recommend a product like ZO’s Daily Power Defence, which prevents oxidation from external and internal aggressors, repairs DNA damage and helps to keep the barrier strong. 

I also recommend the ZO Skin Health Complection Clearing Masque to absorb oil and prevent clogged pores; it can also be for multiple days in a row when the skin is having a flare up, such as due to a change in the seasons or during periods of increased stress. When used for multiple days in a row it helps to control oil and get inflammation under control. It can also be used as an overnight spot treatment.

For those with stubborn, more active or widespread acne, benzoyl peroxide is key. We recommend a 10% concentration, such as ZO Skin Health Acne Control.

Think about adjusting your diet

Making the following dietary tweaks could help to prevent breakouts: 

  • Reducing consumption of milk products: consuming certain milk products, such as milk, cheese and ice cream, seems to worsen acne for some people. 
  • Up your intake of fatty acids: Omega 3 and Omega 6 fatty acids have been shown to help reduce acne breakouts.
  • Maintain a balanced low glycemic index foods diet and eat vegetables from all colours of the rainbow for optimum skin health. 

Ways to prevent acne

It’s not always possible to completely prevent acne, but you can take certain steps to help lower your chances of getting breakouts. 

  • Wash your face daily with a cleanser containing Beta Hydroxy Acids (BHAs), such as salicylic acid
  • Use non-comedogenic make-up, meaning it’s less likely to clog your pores
  • Avoid skincare and make-up products that contain comedogenic oils
  • Use a medicated skincare regime, focusing on all aspects of a healthy skin 
  • Always remove make-up and cleanse the skin thoroughly before bed
  • Exfoliate daily to regulate cell renewal and to prevent cell build up
  • Shower or wash your face after exercising
  • Tie long hair back to keep it off your face
  • Keep your phone clean, or talk via AirPods
  • Avoid tight-fitting hats, headbands and clothing that covers breakout-prone areas
  • Eat a balanced diet and stay hydrated
  • Try to reduce any stress
  • Regular low-to-medium exercise to help minimise stress-induced acne

Seek professional advice

We successfully treat acne every day because our knowledge of acne as a skin condition is extensive and we are active in how we treat the skin. We not only focus on treating the condition itself, but also on improving general skin health for increased luminosity and to help support your skin through the natural ageing process. 

For moderate to severe acne, or for those who are suffering emotionally, we always offer a dermatologist referral; whether that client sees a dermatologist, or we work alongside them, we always take acne seriously and do what is best for our clients. 

We have a huge passion for helping our clients with breakout-prone skin. Our director, Kate Kerr, suffered with acne as a teenager and in her twenties – she still experiences breakouts today if she becomes complacent with her skincare regime and facials, so she understands just how frustrating and upsetting it can be. 

If you would like support with treating your acne, do book in for a consultation – we would love to help.  

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