Acne | Skindoc Dermatologists | Liverpool Sydney | Dr Jennifer Yip

Acne Information – What we need to know.

How prevalent is acne?

Acne is common and burdensome. Global prevalence is 9.4%. It is the second highest global cause of disability from skin diseases. $1.2 billion US dollars is spent in the USA alone.

Acne occurs in at least 85% of young people aged between 12 and 24 yrs, and in Australia, almost 94% of 16 and 18 year olds have the condition.

Acne can occur from adolescence to people in their 30s and even middle age.

What causes acne?

There are 4 key factors

  1. Excess sebum
  2. Proliferation of Cutibacterium acne
  3. Hyperkeratinisation or thickening of the pilosebaceous follicle
  4. Inflammatory mediators – dietary triggers such as meat, dairy and high GI foods can exacerbate acne by increasing production of key mediators.

Role of nutrition in Gut-Skin axis.

Plant-based supplements rich in fibre and polyphenols could be helpful for acne vulgaris. Gut microbiome potentially plays a role in acne pathogenesis.

Omega 3 fatty acids such as fish, low GI diet and probiotics may improve acne. Diets which have high GI and dairy may trigger worsening acne. Consumption of milk proteins such as whey proteins can worsened acne. Whey is a strong stimulant of insulin growth factor IGF-1 pathway.

High glycaemic diet can worsen acne. High GI diets tend to stimulate increase of insulin and IGF-1.

High meat intake leads to increase leucine that ultimately leads to mTOR pathway.

High meat, high milk/dairy intake and high glycaemic diets all lead to activation of mTOR pathway.

Activation of this pathway (mammalian target of rapamycin complex1, Mtorc1) leads to increase lipid synthesis, increase cell growth and cell proliferation and hyperproliferation of Cutibacterium acne.

Gut microbiome changes in acne

The ratio of Proteobacteria (P) versus Actinobacteria (A) is different in people with acne as compared to controls.

  • P/A ratio in acne patients was found to be 9.38
  • P/A ratio in contrls was found to be 2.47
    Short chain fatty acids are underexpressed in patient with acne compared to controls. These short chain fatty acids inhibits production of butyrate in the gut which ultimately leads to lipid in the skin and therefore acne.
    Which bacteria leads to production of short chain fatty acids?
  • Lactobacillus
  • Bifidobacterium

Research is currently underway investigating whether topical probiotics can improve acne spots by decreasing the inflammation. The probiotic species and strain may matter in the management of the disease.


Treatment of acne is tailored to each patient according to the severity, and their condition may fluctuate from time to time. More than 90% of patients consult social media sites before seeking medical attention. Not surprisingly many young patients come to the consultation with multiple acne myths.

Acne can have a significant effect on the person’s psyche and a negative impact on their self-esteem. The psychological impact does not necessarily correlate with the severity of the acne.


Cleansers often contain one of the following active ingredients:

Salicyclic acid, glycolic acid, benzoyl peroxide or azelaic acid.

The skin should be cleansed twice daily to remove excess sebum, keratin debris, make up and sweat and pollution.
Benzoyl peroxide decreases colonisation by C.acne of the pilosebaceous duct, it can also decrease sebum production and the formation of comedones.

Glycolic acid, lactic acid, mandelic acid as well as beta-hydroxy acid and salicylic acid work by exfoliation.
Azelaic acid works by inhibiting C. acne growth and improves pilosebaceous follicular keratinisation. It may be less irritating than benzoyl peroxide.

Mild acne

This form of acne is usually characterised by comedones (opened comedones which are also called blackheads, and closed comedones which are also called whiteheads).

Dual topical combination therapy is said to be more effective, more rapid in onset of action and targets more areas of acne pathogenesis than mono topical therapy.

They include:

  • Adapalene 0.1% or 0.3% and benzoyl peroxide 2.5% (on the PBS)
  • Clindamycin phosphate 1% and benzoyl peroxide 5% (not listed on PBS)
  • Clindamycin phosphate 1% and tretinoin 0.025% (not listed on PBS)
  • Trifarotene 0.005% (not on PBS), with retinoid activity and newest addition which targets the RAR-gamma receptor in skin.

Moderate acne

This form of acne is usually characterised by papules and pustules. It usually requires oral treatment. In women certain types of oral contraceptive pills and spironolactone may be effective. Oral antibiotics can be used in both sexes but should be limited to 3-6 months to decrease the risk of antibiotic resistance. Topical antibiotics should not be used in conjunction with oral antibiotics for this reason.

Antibiotics commonly used in acne include:

Doxycycline 100mg daily. It should be taken with water not milk. It is not recommended below the age of 12 or women who are pregnant or lactating.

Minocycline 100mg daily – rare side effects reported include minocycline-induced hepatitis, drug-induced lupus-like hypersensitivity syndrome and hyperpigmentation.

Erythromycin 500mg twice daily is also effective but GIT upsets and the development of C. acne resistance is more common than with tetracyclines. It can be used in children below 12 years and pregnant women.

Trimethoprim 200mg to 300mg twice daily can be used as third line therapy.

Azithromycin can be as effective as doxycycline as shown in some clinical trials. Regimens for this medication include 500mg three days per week or in cycles of 10 days for 12 weeks are the most commonly used ones.

Hormonal therapy

The most common anti-androgen therapy for moderately severe acne is cyproterone acetate with or without the oral contraceptive pill and spironolactone. These medication decrease ovarian and adrenal androgen production and inhibit the activity of androgen nuclear receptor activity on sebocytes.

Response to hormonal therapy is slow and can take up to 6 to 9 months for maximal improvement although some improvement is generally seen at 3 months. Many women may experience a flare of acne when their long term OCP is ceased.

Cyproterone acetate is usually given in combination with the OCP in doses of 12.5mg to 50mg from the first 10-15 days of the menstrual cycle. Rarely it can be given on its own at 50mg to 100mg daily from day 1-5 of the menstrual cycle.

Spironolactone is an alternative hormonal treatment for women with hormonal acne. It is safe and effective and requires no monitoring in healthy women. Starting doses range from 25mg to 50mg twice daily and increasing up to 200mg daily. Side effects are not common but may include breast tenderness, breakthrough bleeding or headache.

Severe acne

Oral antibiotic and a topical retinoid may be initially considered.

Isotretinoin may need to be considered particularly in patients with severe acne unresponsive to treatment, patients at risk of scarring and patients severely affected psychologically by their acne.

Secondary depression may occur due to acne and eradicating the acne can therefore improve the mood and general well-being of the patient.

Female patients need to counselled on the need for contraception as this drug can be teratogenic. Mood swings can occur on isotretinoin and are not uncommon particularly during the teenage years. Nonetheless isotretinoin is an effective and cost effective treatment in the management of severe acne in patients.

Pregnant women with acne

What cannot be used?

Virtually all oral treatments in particular retinoids such as isotretinoin and tetracyclines are contraindicated. However in moderate to severe cases oral erythromycin and azithromycin are safe during pregnancy. Tetracyclines are not safe as they can lead to the staining of the infant’s first dentition. In addition topical retinoids are also contraindicated.

What are safe options?

Topical treatments such as azelaic acid, glycolic acid, salicylic acid, and niacinamide.

Alternative therapies in severe acne:

Biophotonic light therapy

Biophotonic light therapy (Kleresca) is a non-invasive treatment used increasingly in inflammatory acne. A topical photoconverter chromophore gel is applied to the face. A light emitting multi-LED device is used to activate the gel.

The LED light passes through the gel and is converted into different wavelengths which penetrate the skin to varying depths of skin. It is thought the conversion of light by the gel results in enhanced epidermal and dermal absorption of light.

Fluorescence generated in the skin leads to immunological responses leading to killing to the C.acne, reduction of inflammation and encourages new collagen deposited and help in the repair of acne scars.

The poly-chromatic fluorescent light consists of a spectrum of different wavelengths and is an ultra-fast dynamic pulsing light which allows a sustained immunological response in the skin during treatment.

This treatment is highly efficient in moderate to severe acne.

What is the patient experience during treatment?

Many say they experienced a warmth sensation on the area the gel and light is applied. However the treatment is comfortable and pleasant. There is no pain, no downtime, good tolerability, no discomfort and treatment are fast.

Possible side effects immediately after the procedure include redness. Hyperpigmentation of bronzing of the treatment area can occur but is transient. Slight discolouration of hair can occur but again this is transient.

This treatment is offered at our surgery.

There are two other treatments for moderate to severe acne:

PDT or photodynamic therapy

A photosensitizing medication ALA is applied to the skin for an incubation period of about 45 minutes. The ALA is then activated by a laser or broadband light which leads to photodynamic reaction within target cells such as sebocytes resulting in their destruction. As a result there is inflammation which will take several days to resolve.

Possible side effects include redness, swelling, irritation and hyperpigmentation that can last up to 4 weeks.

Hyperpigmentation is more common in patient with darker complexions.

LED or light emitting diode therapy

The light is non-coherent and non-collimated and is the result of photons moving in random directions at random times generating random frequencies. The light is emitted in a broad and diffuse pattern and is composed of a spread of wavelengths from one area of the light spectrum.

Blue LED leads to destruction of C.acne. The blue light penetrates to a superficial level of the skin where most of the C.acne occurs. The blue LED light will give a cold sensation when applied to the skin.

Red LED is used in the reduction of inflammation associated with acne. Patients will experience a warm sensation when under the red LED.

Occasionally hyperpigmentation can occur with this procedure.

PDT is available at our surgery.

Do complementary and alternative therapies work?

These include tea tree oil, niacinamide, ayuredic compounds, antioxidants, zinc, probiotic treatments and many naturally occurring oils. However, the scientific data on these agents are limited in the area of safety, efficacy, specific ingredients and their concentrations and production processes.

Many ingredients can also cause acne such as isopropyl myristate which is common in skin and hair care products.

New treatments recently released in Australia

These include a combination therapy of 1% clindamycin and 0.025% tretinoin in a gel formulation. The other is trifarotene 0.005%, a fourth-generation retinoid foam for face and body.

New treatments available in USA

These include minomycline foam. The other is a topical anti-androgen, clascoterone. Both are not available in Australia at the present time.


Acne is no doubt can be a very distressing condition yet very common condition. Many young people will consult social media for advice prior to seeking medical advice. Our role as a dermatology specialist practice is to listen to the concerns of our patient, take a detailed history and examination and finally discuss with them their individualised treatment options.

As dermatologists our role is to use our medical expertise and scientific knowledge to help our patients with troublesome acne.