Key learning points:
- Acne tends to affect people during their teenage years, but can also affect some people during adulthood
- Acne should start to improve after six weeks of treatment, but around one in five people will not react well to treatment
- Initial application of topical treatments may cause irritation, so patients should gradually increase the amount of time on the skin
Acne vulgaris (meaning ‘common’ in Latin) is often viewed as a rite of passage for teenagers and as such is often ignored by patients, parents and practitioners. The peak incidence of acne for both sexes is between 13 and 16 years and 70% of acne cases will resolve after five years. However, for some individuals, the condition may persist into adulthood, affecting up to 12% of women and 3% of men over the age of 25 and impacting on their wellbeing.[1,2] Treatment may be required to improve both the physical appearance of acne and prevent physical and psychological scarring.
Pathogenesis of acne
The pathogenesis of acne is complex and centers on the pilosebaceous unit, which consists of a hair shaft, hair follicle, follicular duct and sebaceous gland. Factors involved in the pathophysiology include:[1,3]
- Androgen-induced seborrhoea (excess grease production). The more sebum (grease), the greater the degree of acne. Sebum is produced by the sebaceous 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.
- Abnormal keratinisation (hyperkeratinisation). Comedone formation (blackheads, whiteheads and microcomedones), which is known as comedogenesis, is due to an abnormal proliferation and differentiation of ductal keratinocyte. It is controlled, in part, by androgens.
- Colonisation with Propionibacterium acnes. This occurs at a later stage in the development of lesions (especially inflammatory lesions). The seborrhoea and comedone formation alter the ductal micro environment, which results in colonisation of the duct.
- Release of inflammatory mediators: a complex process involving an interaction between the biological changes occurring in the duct, comedone formation and P. acnes colonisation and the patient’s cellular (especially lymphocytes) response within the dermis, which responds to pro-inflammatory cytokines spreading from the duct to the dermis.
Diagnosis and Clinical Presentation
For the majority of patients presenting with acne, diagnosis is based on their demographics (adolescents or young adults), clinical presentation and distribution of lesions, usually on the face, chest and back:[1,4]
– Seborrhoea (greasy skin).
– Non-inflamed lesions – comedones: open comedones (blackheads) and closed comedones (whiteheads).
– Inflamed lesions – papules, pustules and nodules.
– Scarring – loss of tissue (atrophic or ice-pick scar) and increased fibrous tissue (hypertrophic or keloid scar).
– Post-inflammatory hyperpigmentation.
Early diagnosis and thorough clinical assessment are important for a number of reasons. Some patients will be destined to develop more severe acne or respond less well to treatment, so it is important that clinicians recognise these poor prognostic factors.
A careful history and examination, looking for the following factors, will identify at-risk individuals:
- Early age of onset for acne in both sexes and in girls relatively earlier menarche and higher levels of dehydroepiandrosterone.
- Early presentation with mid-facial lesions, predominantly comedones.
- Marked seborrhoea.
- Truncal acne.
- Strong family history of acne and/or scarring.
- Development of scarring.
- Psychological issues as a result of acne.
Assessment and recognition of specific lesions and the degree of seborrhoea will inform the management and selection of therapies that target the specific clinical presentation as well as aetiological factors. It is also important to assess the patient’s mental state because acne is associated with increased psychiatric morbidity.[1,2]
Management and treatment
Effective management of acne requires support, the prescribing of effective treatments based on severity (box 1, left), to treat the four pathological factors. Management should include practical, realistic advice about caring for the skin (box 2, right), address individual concerns and expectations about the treatment options that will impact on adherence with the focus being to treat without delay, to reduce or clear lesions with minimal side-effects, to prevent physical and emotional scarring and reduce antibiotic resistance.
The choice of products to prescribe is succinctly covered in the PCDS 2016 Guideline. The following provides an overview of treatment options, but there still remain unanswered questions, both from clinicians and patients (see box 3, below).
It is essential that topical therapies are applied correctly and regularly. Initial application may cause irritation, therefore short contact (eg 30 minutes followed by washing off), with gradual increasing amounts or alternate day applications will aid tolerability. Products must be applied to all acne-prone areas rather than just specific lesions to prevent follicle development. Products include:
- Topical retinoids Topical retinoids are the mainstay for comedonal acne treatment. They have impact on inflammatory lesions and enhance the efficacy of other topical therapies.
- Topical antimicrobials Non-antibiotic antimicrobials, including benzoyl peroxide (BPO) and azelaic acid, should be used in preference to topical antibiotics because of bacterial resistance.
- Topical antibiotics Although topical antibiotics are effective in inflammatory acne, they have little impact on comedonal lesions. The main issue with topical antibiotics relates to bacterial resistance and they should be used with BPO.
- Oral antibiotics Oral antibiotics in acne must only be used when indicated for extensive disease, which includes truncal acne and moderate to severe papulopustular acne and they should never be used as monotherapy because of antibiotic resistance.
- Hormonal therapies All combined oral contraceptives (COC) have the potential to reduce acne through their oestrogenic effects. One ethinylestradiol/cyproterone acetate preparation has a licence for the treatment of severe acne, but is not licensed as a contraceptive agent in the UK.
Follow-up and referral
Improvements should be seen after six weeks, so patients should be assessed at this point and regularly afterwards. Approximately 20% of patients will show a poor response. The reasons include:
- Wrong diagnosis.
- Poor adherence to therapy.
- Inappropriate assessment of overall acne severity.
- Side-effects or intolerance of therapy.
- Resistance to P. acnes.
- Underlying conditions (congenital and adrenal hyperplasia) polycystic ovary syndrome (PCOS).
Patients with severe disease and poor prognostic risk factors should promote early referral (box 4, left) for consideration of isotretinoin (which is licensed as a second-line therapy for acne that has not responded to combination regimens).
Acne is common and can be treated effectively in primary care.
Box 1 – Acne severity
- Predominantly comedonal lesions
- Open (blackheads) and closed (whiteheads) comedones
- Few papular inflammatory raised lesions
- Typically limited to the face
- Open and closed comedones
- Greater number of inflammatory papules and pustules, involving the face and trunk
- A risk of scarring
- Open and closed comedones
- Papular and pustular inflammatory lesions
- Nodular-cystic lesion
Box 2 – Skin care advice
- Wash the face gently using a mild cleanser, once in the morning and once in the evening, as well as after heavy exercise. Wash from under the jaw to the hairline, and rinse thoroughly.
- Consider using a cleanser designed for acne and avoid strong soaps or rough scrubs as these can make the problem worse. Don’t use astringents unless the skin is very oily, and then only on oily spots.
- Men should try both electric and safety razors for shaving to see which is more comfortable, shaving gently and only when necessary, to reduce the risk of nicking skin lesions.
- Avoid picking or squeezing spots, as this may aggravate them or cause scarring.
- Wash hair regularly – every day if it is oily.
- If wearing makeup, use oil-free, water-based make-up and choose products that are labelled as ‘non-comedogenic’ (this means they should not cause blackheads or whiteheads) or non-acnegenic (should not cause acne). Remove makeup at night with mild soap or a gentle cleanser and water.
- Be careful in the sun. Many of the treatments for acne can make patients more prone to sunburn. Limit the time spent in the sun and use an effective sun block.
Box 3 – Top 10 research priorities for the treatment of acne
- What management strategy should be adopted for the treatment of acne in order to optimise short and long-term outcomes?
- What is the correct way to use antibiotics in acne to achieve the best outcomes with least risk?
- What is the best treatment for acne scars?
- What is the best way of preventing acne?
- What is the correct way to use oral isotretinoin (Roaccutane) in order to achieve the best outcomes with least risk of serious adverse effects?
- Which lifestyle factors affect acne susceptibility or severity the most and could diet be one of them?
- What is the best way of managing acne in mature women who may or may not have hormonal abnormalities?
- What is the best topical product for treating acne?
- Which physical therapies, including lasers and other light-based treatments, are safe and effective in acne?
- How long do acne treatments take to work and which ones are fastest acting?
Box 4 – Refer patients when:
- They are developing scarring, or are at risk of developing it, despite primary care interventions.
- They have moderate acne that has failed to respond adequately to treatment (treatment failure should be judged on the person’s perception of their condition) over a period of at least 6 months.
- Diagnostic doubt.
- They have a severe variant of acne with systemic symptoms (such as acne fulminans) – urgent dermatology referral.
- They have severe acne with painful, deep, nodules or cysts (nodulocystic acne).
- They have severe psychosocial problems, including
- a morbid fear of deformity (body dysmorphic disorder) – refer to psychiatry.
- They are suspected of having an underlying endrocrinological cause for their acne (such as polycystic ovary syndrome) – refer to endocrinology or gynaecology).
- Acne Priority Setting Partnership: acnepsp.org
- British Association of Dermatologists Patient Information Leaflet- Acne: bad.org.uk/shared/get-file.ashx?id=65&itemtype=document
- DermNet New Zealand: dermnetnz.org/topics/acne-vulgaris
- Primary Care Dermatology Society Clinical Guidance Acne Vulgaris: pcds.org.uk/clinical-guidance/acne-vulgariselectronic
- Medicines Compendium (eMC): medicines.org.uk/emc/
- Advice on the safe introduction and continued use of isotretinoin in acne in the UK 2010.Goodfield MJD, Cox NH, Bowser A, McMillan JC, Millard LG, Simpson NB, Ormerod AD. Br J Dermatol 2010; 162: 1172-1179. bad.org.uk/shared/get-file.ashx?id=50&item type=document
1 Layton A, Mawson R. The psychological impact of acne should not be underestimated. Guidelines in Practice 2012. guidelinesinpractice.co.uk/jun_12_layton_acne_jun12
2 Mawson R. Practical implementation tips: acne. Guidelines in Practice 2016. guidelinesinpractice.co.uk/acne-practical-implementation-tips
3 Lavers I. Diagnosis and management of acne vulgaris. Nurse Prescribing 2014;12:330-6.
4 Primary Care Dermatology Society Clinical Guidance Acne Vulgaris 2016: pcds.org.uk/clinical-guidance/acne-vulgaris
5 Lavers I. Acne Vulgaris-diagnosis, management and optimising patient care. Dermatological Nursing 2014;13:16-25
6 Layton A, Eady EA, Peat M et al. Identifying acne treatment uncertainties via a James Lind. Alliance Priority Setting Partnership BMJ Open 2015;5:e008085. doi: 10.1136/bmjopen-2015-008085
7 Acne Academy: acneacademy.org
8 National Institute for Health and Care Excellence (NICE) CKS 2014: cks.nice.org.uk/acne-vulgaris#!topicsummary