Primary Care Dermatology Society
The leading primary care society for dermatology and skin surgery

Acne vulgaris

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Latest update 16/10/2010

Acknowledgements

I would like to thank Dr. Alison Layton (Consultant Dermatologist at the Harrogate and District Foundation Trust) Dr. Daron Seukeran (Consultant Dermatologist at the Royal Berkshire Hospital), Dr Tom Poyner (GPwSI in Teesside) and the British Skin Foundation, which funds high-quality research into skin disease and skin cancer

This chapter is set out as follows:

Introduction

  • Virtually every adolescent has a few “spots” however about 15% of the adolescent population have sufficient problems to seek treatment
  • In most patients, but not all, the acne clears up by the late teens or early 20s. More severe acne tends to last longer
  • A group of patients have persistent acne lasting up to the age of 30 - 40 years, and sometimes beyond. Patients with persistent acne often have a family history of persistent acne
  • It is not infectious and to date there is no clear cut evidence to implicate diet
  • Acne may scar – most of the time this is preventable by using the correct treatment given in a timely fashion

Aetiology

The aetiology of acne has 4 major features:

  • Androgen induced seborrhoea (excess grease)
    • The more sebum (grease) the greater degree of acne
    • Sebum is produced by the pilosebaceous glands, which are predominantly found on the face, back and chest
    • Evidence suggests that in most patients the seborrhoea is due to increased response of the sebaceous glands to normal levels of plasma androgens
  • Comedone formation (blackheads, whiteheads and microcomedones), which is known as comedogenesis
    • Is due to an abnormal proliferation and differentiation of ductal keratinocytes
    • It is controlled, in part, by androgens
    • In pre-pubertal subjects comedones are seen early and they precede the development of inflammatory lesions
  • Colonisation of the pilosebaceous duct with P. acnes
    • Is a later stage in the development of acne lesions (especially inflammatory lesions)
    • The seborrhoea and comedone formation alter the ductal micro environment which results in colonisation of the duct
    • P. acnes is the most important or ganism
  • Production of inflammation. This is a complex process involving an interaction between:
    • Biological changes occurring in the duct as a result of comedone formation and P. acnes colonisation of the duct
    • And the patients cellular (especially lymphocytes) response within the dermis, which responds to pro-inflammatory cytokines spreading from the duct to the dermis

Factors which can/might modify acne

  • Hormonal factors
    • About 70% of females will notice an aggravation of the acne just before or in the first few days of the period
    • Polycystic Ovarian Syndrome (PCOS) / other endocrinological disorders – please refer to investigations
  • UV light can benefit acne
  • Stress
    • This is a controversial issue - there is some evidence that stress makes acne worse but data to support this view is limited
    • Stress may manifest itself as acne excoriee, where patients, usually females habitually scratch the spots the moment they appear (see later under ‘acne variants’)
  • Diet – as yet there is no clear evidence
  • Cosmetics
    • Caused by oil-based cosmetics
    • Pomade acne is caused by hair pomades, with comedonal and papulopustular acne on the forehead and temples
  • The following drugs may cause acne:
    • Topical and oral corticosteroids
    • Anabolic steroids
    • Lithium
    • Ciclosporin
    • Iodides taken orally, which may be part of some homoeopathic therapies
Figure 1 – Acne associated with PCOS
Figure 2 – Acne excoriee
Figure 3 - Pomade acne
Figure 4 – Anabolic steroid-induced acne
Figure 5 – Lithium-induced acne

Clinical findings

  • Greasy skin (seborrhoea)
  • Non-inflamed lesions i.e. comedones – blackheads and whiteheads (these can be difficult to see, stretching the skin usually helps)
  • Inflamed lesions – papules, pustules and nodules
  • Scarrring, which may be due to:
    • Loss of tissue, the so called atrophic or ice pick scar
    • Increased fibrous tissue, the so called the hypertrophic or keloid scar
  • Pigmentation, which can be a problem especially in dark skin

It is important to assess whether the lesions are inflammatory, non-inflammatory or both as this might influence the choice of topical treatments

Figure 6 – Blackheads
Figure 7 – Whiteheads
Figure 8 - Inflammatory acne with papules and pustules
Figure 9 – Inflammatory acne; many pustules and actively inflammed nodules
Figure 10 – Cystic acne
Figure 11 – Nodules less inflammed; been present for two months
Figure 12 -  Ice pick scars
Figure 13 - The start of atrophic scarring

This has developed from previous severe inflammatory acne
Figure 14 – Severe inflammatory acne nodules now progressing into keloid scars
Figure 15 – Keloid scars
Figure 16 – Hyperpigmentation

Investigations

  • The vast majority of patients with acne do not require investigations
  • Free testosterone levels should be checked in patients suspected of having the polycystic ovarian syndrome, which is suggested by:
    • Oligomenorrhoea (less than 9 periods a year)
    • Hirsutism
  • Patients found to have a testosterone level greater than 5 nmol/l, or have other features of virilisation should be referred urgently to an endocrinologist to rule out a serious underlying disorder

Management

Provide a patient information leaflet

Assessment- factors that will affect treatment choice:

  • Duration of acne
  • Family history – a strong family history is a poor prognostic factor
  • Response to previous treatment
  • Compliance
  • Anything to suggest that the acne is atypical
  • Psychosocial effects of the disease – some patients with ‘mild’ acne may become very depressed
  • Overall acne severity at all sites
  • Predominant types of lesions: comedonal, inflammatory or both
  • Scarring
  • Pigmentation

I) Treatment of comedonal acne (figure 17)

  • First line
    • Normally a topical retinoid e.g. Differin ® (adapalene), Isotrex ® (isotretinoin) or Retin-A ® (tretinoin)
    • Apply once a day
    • Explain to the patient that these treatments will normally dry the skin. Patients may wish to start 2-3 nights a week and gradually increase the frequency of applications. A non-oil based moisturiser can also be used
  • Other options
    • An alternative topical retinoid, azelaic acid or salicylic acid

II) Treatment of mild papular/pustular acne (figure 18)

  • Use both a topical retinoid and a topical anti-microbial
  • Topical retinoids – as in I (above)
  • Topical anti-microbials include Zineryt ® (erythromycin and zinc), Dalacin T ® (clindamycin) and 5% benzoyl peroxide
  • Treatments can either be used as:
    • A separate retinoid and anti-microbial at opposite ends of the day
    • Combined preparations e.g. Aknemycin ® Plus (tretinoin and erythromycin), Duac ® Once Daily (clindamycin and 5% benzoyl peroxide) or Epiduo ® (2.5% Benzoyl Peroxide gel and adapalene)

III) Treatment of moderate inflammatory acne (figure 19)

  • Combine systemic antibiotics with topical agents
  • First choice of antibiotic:
    • Normally a tetracycline
    • Oxytetracycline 500mg BD is cheaper however in some patients it may not be as effective as the other tetracyclines. Also tetracyclines should be taken 60 minutes before or after food and so compliance can be an issue
    • Other tetracyclines include lymecycline 408mg OD (Tetralysal ® 300) and doxycycline 100mg daily. The latter can occasionally cause a photosensitive eruption
    • Minocycline is rarely used due to the increased risk of hepatotoxicity and lupus-like conditions
    • Tetracyclines are contra-indicated in pregnancy and in patients aged under 12
  • Other antibiotics
    • Erythromycin 500mg BD
  • Which topical agents to use in combination?
    • Topical retinoids
    • Topical antimicrobials e.g. benzoyl peroxide
  • It is not advisable to prescribe oral and topical antibiotics of different chemical groups simultaneously

IV) Moderate-severe acne in a woman

  • If no contra-indications consider adding in Dianette ® to the topical/systemic treatments referred to above
  • Dianette may be of particular value in patients with significant endocrinopathies such as the polycystic ovarian syndrome
  • Once a sustained improvement (3 months) has been seen withdraw the Dianette

Acne in pregnancy

The following are usually regarded as being safe should the physician and patient feel it necessary to prescribe during pregnancy:

  • 5% Benzoyl peroxide
  • 2% topical erythromycin
  • If the acne is troublesome and not responding to topical treatments consider oral erythromycin, 500mg b.d.
Figure 17 – Comedonal acne
Figure 18 – Mild papular/pustular acne
Figure 19 – Moderate inflammatory acne

Follow up of patients

  • It is important to have a way of monitoring response to treatment. This could be done as follows:
    • Serial photography is perhaps the best method
    • Using standardised grading methods (see below)
  • Duration of treatment 
    • Once patients have had a sustained improvement to treatment (at least 3 months) consider discontinuing systemic treatment – at this stage continue topical treatments
    • Since acne lasts for several years some form of treatment will be required for much of this time
    • For much of this time this could be an appropriate topical treatment
    • When the acne begins to flare a relevant systemic treatment should be added
Figure 20 – Face, grade 1+2
Figure 21 - Face, grade 3+4
Figure 22 - Face, grade 5+6
Figure 23 - Face, grade 7+8
Figure 24 - Face, grade 9+10

Figure 25 - Face, grade 11+12
Figure 26 – Trunk, grade 2+1

(please note the milder case i.e. grade 1 is the photo on the right)
Figure 27 – Trunk, grade 4+3

(please note the milder case is the photo on the right)
Figure 28 – Trunk, grade 6+5

(please note the milder case is the photo on the bottom)
Figure 29 – Grade 8-7

(please note the milder case is the photo on the bottom)

Poor responders to treatment

  • Poor compliance – this may be due to a long history of acne or side effects of treatment such as photosensitivity caused by doxycycline or irritation to topical treatments. If local irritation / dermatitis develops consider:
    • Stop the treatment for a few days
    • Use an oil free moisturiser once or twice a day; the moisturiser can also be used, if necessary, while still using the topical treatment but must not be applied at the same time
    • If necessary use 1% hydrocortisone cream for five days twice daily
    • Reintroduce the treatment gradually e.g. 2-3 nights a week
  • P. acnes resistance
    • Relevant for 10-20% of patients on tetracycline; 65% on erythromycin
    • More likely in patients who have received many oral and or topical antibiotics, and in those who were doing well and are now responding badly
    • Where P.acnes resistance is suspected changing topical treatment to 5% benzoyl peroxide twice-daily may help, and consider changing the type of systemic antibiotic
  • Wrong diagnosis e.g. rosacea
  • Acne variants – see later
Figure 30 – Photosensitivity from doxycycline
Figure 31 – Irritant dermatitis

Who to refer

  • Who to refer
    • Severe acne – refer early
    • Moderate acne only partially responding to treatment and starting to scar
    • Inadequate response to at least two systemic antibiotics PLUS topical treatments, each given for a minimum of 3 months
    • Patients with associated and severe psychological symptoms, regardless of the physical signs
  • Treatment options in secondary care include:
    • Oral isotretinoin (see below)
    • High dose oral antibiotics such as lymecycline 408mg BD or trimethorpim 300mg BD
    • Dianette ®+ cyproterone acetate (50-100 mg/10 days)
    • Short courses of oral corticosteroids may be required

Prescribing isotretinoin in the community

The current Medicines and Healthcare products Regulatory Agency (MHRA) view on isotretinoin prescribing is as follows (March 2007):

The Summary of Product Characteristics in the licence for isotretinoin states that it can be prescribed by or under supervision of physicians with expertise in the use of systemic retinoids for the treatment of acne and a full understanding of the risks of isotretinoin and monitoring requirements. This wording is chosen for compliance with other European states but in the United Kingdom refers to consultant dermatologists

Consultant dermatologists and experienced GPwSIs working within an integrated service may wish to develop a locally agreed care pathway and accreditation process to facilitate the prescribing of isotretinoin in the community. However, they need to be mindful that this is an 'off-licence' indication and be cognisant of the MHRA view. They may also wish to seek the advice of their professional indemnity organisation

Management of scarring

Sometimes, but not often, some scars naturally improve over many years. Treatment of established scars is difficult and in some patients may produce no improvement whatsoever. Patients should only be referred to dermatologists / plastic surgeons familiar with treating scars. Funding will vary depending on local commissioning arrangements

Atrophic scars

  • The development of ablative lasers combined with appropriate surgical techniques has led to a significant improvement in the way that certain atrophic scars can be treated
  • Punch excision of small atrophic scars which can be very helpful prior to resurfacing
  • For deep scars – scar revision may help
  • Other options include intradermal injections of collagen or compounds which stimulate collagen synthesis

Hypertrophic / keloid scars

  • Silicone gels applied to scars can be prescribed by General Practitioners
  • Local steroids for a trial period of 2-3 months. Look closely for side effects such as skin thinning and telangiectasia. Treatments can be administered as follows:
    • Topically i.e. dexamethasone cream carefully applied
    • Haelan ® tape (fludroxycortide)
    • Intradermal triamcinolone
  • Pulsed dye laser, which can reduce the redness of scars and flatten them. This procedure is only possible through specialised hospital departments
Figure 32 – Ice pick scars
Figure 33 – Atrophic scars
Figure 34 – Keloid scars

Acne variants

  • Pre-pubertal acne
  • Acne excoriee
  • Sandpaper acne
  • Macrocomedones
  • Acne conglobata
  • Acne fulminans

Pre-pubertal acne

  • Pre-pubertal acne is very uncommon
  • It is more common in boys and presents between the ages of three and 18 months, and may last up to the age of three years
  • The severity is usually mild-moderate but occasionally can be severe
  • The face is most frequently affected site often with a mixture of inflammatory and non inflammatory lesions
  • There are usually no significant underlying endocrinopathies, and in the absence of precocious puberty or other developmental abnormalities investigations are not needed
  • The treatments are topical retinoids and/or benzoyl peroxide and if necessary oral erythromycin. Tetracycline’s must be avoided because of the risk of permanent tooth discoloration

Acne excoriee

Acne excoriee is uncommon and occurs particularly in young females. There are two reasons for this presentation:

  • Very occasionally patients with very mild acne just pick acne spots in the belief that simply by so doing that will help the acne. A simple explanation from the doctor of the harm that they are doing can help considerably
  • In the other subgroup, the majority, there may be underlying psychological problems, which are often difficult to unravel. There may even be no pathological acne lesions, the patient just scratches the skin - such patients may be considered to have dermatitis artifacta and /or dysmorphophobia. The general practitioner may be in a better place to offer relevant management as they would know the patient and their family better than a consultant dermatologist. Patients with more severe symptoms may need to be referred to a psychiatrist. Should any acne lesions be present then the least irritant topical treatment is required and it may be necessary to add in oral antibiotics

Sandpaper acne

  • Multiple small whiteheads (closed comedones), associated with superficial inflammation
  • The skin is rough to feel - like fine sandpaper
  • Although some cases respond to standard treatment (see below) others don’t. Poor responders often do well with a low dose of isotretinoin (0.5mg/Kg/day) for 4 months

Macrocomedones

  • Are effectively large whiteheads more frequent on the face than the chest 
  • They need to be treated – these are treated by gentle cautery given by someone familiar with the technique. Such patients should not receive isotretinoin until the macrocomedones have been treated otherwise a severe inflammatory response can develop

Acne conglobata

  • An ill-defined form of severe acne
  • Characterised by severe disease on the face and trunk with superficial and deep inflammatory lesions and non-inflamed lesions. Typically blackheads are grouped in clusters of 3-7 lesions which frequently become inflamed producing sinus tracts
  • Treatment is difficult. The patient should be considered and treated has having severe disease but unfortunately oral retinoids are not always successful. Consequently severe scarring is the rule and associated hidradenatis suppuritiva is common

Acne fulminans

  • Is very uncommon
  • It typically presents in mid-teenage boys who may have had for a few years mild acne which over a matter of a few weeks changes into severe inflammatory acne especially on the trunk
  • It is associated with systemic symptoms such as a fever, arthritis and lethargy
  • Treatment is an urgent referral to a consultant dermatologist for likely treatment with oral steroids followed by the introduction of low dose oral isotretinoin. Hospitalization may be required If inadequately treated acne fulminans will result in severe scarring
Figure 35 - Pre-pubertal acne
Figure 36 - Pre-pubertal acne
Figure 37 – Acne excoriee
Figure 38 - Sandpaper acne
Figure 39 - Sandpaper acne
Figure 40 – Macrocomedones
Figure 41 – Acne conglobata
Figure 42 – Acne fulminans
Figure 43 – Acne fulminans