What is acne? Everything you need to know       

Acne is a common skin pathology affecting the pilosebaceous follicles (pores) on the face, thorax and back, which leads to the appearance of lesions. It is the reason behind as many as 20% of dermatological consultations and encountered by the vast majority of adolescents, as well as many adults. In France, one out of every four people between 20 and 40 years of age states that they have acne*.

*SOURCE : Arcane Research Study France – February 2017

What causes acne?

Before we start exporing different ways to treat acne, let’s take a close look at the mecanisms that affect acne-prone skin.


Specialists refer to this as hyperseborrhea (too much sebum) and dyseborrhea (poor quality of sebum). Unlike healthy sebum, acne-including sebum lack vitamin E and oxidizes easily.

The skin sloughs off less and thickens, which plugs the pores that usually evacuate sebum.

At this point, an open comedo develops, more commonly known as a blackhead. The black colour is because the sebum is oxidised by the air

This accumulated sebum is the ideal place for the bacteria responsible for acne, Cutibacterium acnes, to develop. The inflammatory stage has been reached and a closed comedo forms – a painful red spot.

What are the different grades of acne ?


Open comedones are the result of accumulated sebum, dead cells, melanin and keratin. They stretch the pore open, allowing the sebum to oxidise and turn black.


Closed comedones form as a result of accumulated sebum that has been colonised by Cutibacterium acnes. The pore remains closed, keeping the inflammation inside the skin.


A papule is an inflamed lesion. These pimples are often red and can be both sensitive and painful to the touch.


These inflamed lesions with a white cap differ from papules because they are typically filled with pus.


This is a severe type of acne lesion. Nodules develop under the skin and are not typically filled with pus. As a result, they can feel hard to the touch.


This is another kind of severe acne lesion that has become deeply inflamed and filled with pus. Cysts feel softer to the touch than nodules, but they are generally very painful.

What are the different grades of acne?

The European Academy of Dermatology and Venereology has defined specific acne grades according to symptoms and severity. This is known as the Global Evaluation Acne (GEA) scale.

Grade 1 : Very light acne

The European Academy of Dermatology and Venereology has defined specific acne grades according to symptoms and severity. This is known as the Global Evaluation Acne (GEA) scale. 

Grade 2 : Light acne

Less than half the face has open or closed comedones and occasional papulo-pustules.

Grade 3 : Moderate acne

More than half the face has numerous papulo-pustules and comedones, as well as occasional cysts and nodules.

Grade 4 : Severe acne

The entire face is covered in numerous papulo-pustules, comedones and some cysts and nodules.

Grade 5 : Very severe acne

The entire face is covered in multiple cysts and nodules. 

Acne placement refers to where the lesions most commonly occur. Pimples mainly appear on the face.

With more oil glands, the T-shaped area across the forehead and down the nose is a prime location for blackheads and whiteheads. Pimples along the hairline may be due to the choice of haircare products. 

Breakouts on the cheeks may occur as a result of acne mechanica, which develops due to friction or rubbing of the skin.

The jawline and chin are thought to sensitive to hormones. Compared to T-zone pimples, the acne lesions are likely to be deeper, bigger, and more inflamed.

Different factors can trigger or aggravate acne, including age, hormonal changes, skin type and genetics.

  • Gender. For many women, acne persists for decades with flareups common before their period. 
  • Hormonal changes. Androgen hormones increase in boys and girls during puberty and cause the sebaceous glands to get bigger and produce more sebum. Hormone changes in midlife may also lead to breakouts.
  • Certain medications. This includes treatments containing corticosteroids, testosterone and lithium.
  • Stress. Stress doesn't cause acne, but if you have acne, stress may make it worse.Genetics: If your parents had acne, there is a greater risk that you will too.
  • Increased sensitivity to male hormones. Hormones influence both sebum production and hyperkeratinisation, even among girls.
  • The environment. Links have been established between acne and stress, smoking, diet and pollution – not forgetting exposure to endocrine disruptors and poorly chosen cosmetic products.

Food on acne Eating chocolate and greasy foods has not been proven to have any significant effect on acne. Although it goes without saying that a balanced diet with lots of fruit, vegetables and low-glycemic complex carbs has many health benefits. Some foods are thought to be particularly good for your skin as they contain vitamin A and E, antioxidants and zinc.
Acne is not caused by dirty skin In fact, scrubbing the skin too hard or cleansing with harsh skincare products irritates the skin, making acne worse.
Cosmetics and acne Cosmetics don't always make acne worse, especially if you choose oil-free makeup that doesn't clog pores (non-comedogenic).

If self-care remedies and over-the-counter products do not clear your acne, it is a good idea to see your primary care doctor. They can prescribe stronger medications and adapt the treatment to your specific needs. If acne persists, is severe or makes you feel very self-conscious, they may recommend seeing a dermatologist or paediatric dermatologist.

Given that acne has different causes and degrees of severity, the choice of treatment varies. Here are the different types of treatment recommended by the European Academy of Dermatology and Venereology. 

The Academy recommends local treatments, generally retinoids or benzoyl peroxide.

Doctors often prescribe a combination of retinoids and benzoyl peroxide for local application. If after three months the acne persists, a local antibiotic treatment can be added, before moving on to an oral antibiotic treatment from the cycline family.

If these therapeutic strategies don’t work, oral isotretinoin can be considered, especially if there is a high risk of scarring.

Oral isotretinoin is prescribed, especially if there is inflammation. It is recommended to eliminate comedonal lesions with microsurgery before starting the treatment.

Resulting from complex genetic and physiological causes, acne cannot always be prevented. However, there are simple ways to reduce the likelihood of suffering from pimples and outbreaks or reduce the appearance of acne lesions. 
1. Wash your face when you sweat, especially after working out, so dirt, sweat and oil do not cling to your skin

2. Avoid anything that could irritate your skin, from abrasive cleansers to sponges and excessive scrubbing

3. Use alcohol-free products ideally formulated for oily skin, like the Sébium range 

4. Resist the temptation to squeeze spots or touch your face too often to prevent further inflammation and a longer healing time