In mild acne (predominantly facial), open and closed comedones (blackheads and whiteheads) predominate but papules and pustules may also be present. Although the physical severity of the condition is limited and scarring is unlikely, the psychosocial impact may be disproportionate in some people, which is an indication for more aggressive treatment.

Treat initially with a single topical agent; drug choice depends on whether comedonal or inflammatory lesions predominate.

Benzoyl peroxide or topical retinoids are first choice agents for mild comedonal acne whereas benzoyl peroxide is the topical agent of choice for mild inflammatory acne.

The lower concentrations of benzoyl peroxide seem to be as effective as higher concentrations in reducing inflammation. It is usual to start with a lower strength and to increase the concentration of benzoyl peroxide gradually. Adverse effects include local skin irritation, particularly when therapy is initiated, but the scaling and redness often subside with treatment continued at a reduced frequency of application.

Azelaic acid has antimicrobial and anticomedonal properties. It may be an alternative to benzoyl peroxide or to a topical retinoid for treating mild to moderate comedonal acne, particularly of the face. Some patients prefer azelaic acid because it is less likely to cause local irritation than benzoyl peroxide. Azelaic acid can lighten the colour of the skin, but this is rarely problematic in practice (it also has a role in reducing post-inflammatory hyperpigmentation in people with dark skin).

Preparations containing sulphur and abrasive agents (such as aluminium oxide) are not considered beneficial for acne. Topical corticosteroids should not be used in acne. Salicylic acid is a common ingredient in over the counter acne treatments, but it is considered less effective than the topical retinoids.

NHS England (NHSE) has published new prescribing guidance for various common conditions for which over the counter (OTC) items should not be routinely prescribed in primary care (quick reference guide). One of these conditions is mild acne.

Many of these products are cheap to buy and are readily available OTC along with advice from pharmacies. Some self-care medicines are available from shops and supermarkets. Please click here for further information, exceptions, and a patient leaflet.

Benzoyl peroxide

• See section 13.6.1 Topical preparations for acne

Adapalene

• See section 13.6.1 Topical preparations for acne

Azelaic acid

• See section 13.6.1 Topical preparations for acne

Follow-up and review

Assess response to treatment after a period of about 6–8 weeks, and continue treatment if the drug has had a positive effect. The decision to continue treatment should be made on an individual basis. Factors to consider include the original severity of the acne, the psychological disability caused by the acne, and adverse effects of treatment. Benzoyl peroxide and topical retinoids may be used indefinitely (either alone or in combination together) provided adverse effects do not occur. It may be possible to reduce application to alternate days or less frequently during maintenance.

If no improvement is seen after 6–8 weeks, check adherence to treatment. If adherence is poor, this may be because the treatment is poorly tolerated. Consider:

• Reducing the strength of treatment (e.g. reducing from 5% to 2.5% benzoyl peroxide)
• Switching to an alternative topical drug that causes less irritation (e.g. azelaic acid)
• Using a different formulation of drug (e.g. cream instead of a drug with an alcoholic base)

If adherence is adequate, consider:

• Increasing the drug strength and/or frequency of application
• Combining different topical products
  • A topical antibiotic combined with benzoyl peroxide or a topical retinoid is the preferred regimen, as it is proven to be effective and may limit the development of bacterial resistance. Where possible, a topical antibiotic course should be limited to a maximum of 12 weeks and consider using benzoyl peroxide monotherapy as a substitute after this time
  • A topical retinoid combined with benzoyl peroxide is an alternative, but this may be poorly tolerated

In moderate acne, inflammatory lesions (papules and pustules) predominate. The acne may be widespread involving the upper torso, there may be a risk of scarring, and there may be considerable psychosocial morbidity, all of which are indications for aggressive treatment.

Topical combination products

For moderate acne, or mild acne that has failed to respond to initial treatment, a combination product is recommended. A topical antibiotic combined with benzoyl peroxide or a topical retinoid is the preferred regimen, as it is proven to be effective and may limit the development of bacterial resistance. Where possible, a topical antibiotic course should be limited to a maximum of 12 weeks. Topical retinoid combined with benzoyl peroxide is an alternative, but this may be poorly tolerated.

If no response, initiate oral antibiotics withdrawing the topical antibiotic but continuing with topical retinoid or benzoyl peroxide monotherapy as appropriate.

Also consider an oral antibiotic combined with either a topical retinoid or benzoyl peroxide if there is acne on the back or shoulders that is particularly extensive or difficult to reach, or if there is a significant risk of scarring or substantial pigment change.

Duac Once Daily (Clindamycin plus benzoyl peroxide)

• See section 13.6.1 Topical preparations for acne

Treclin (Tretinoin plus clindamycin)

• Seesection 13.6.1 Topical preparations for acne

Epiduo (Adapalene plus benzoyl peroxide)

• See section 13.6.1 Topical preparations for acne

Oral antibiotics

An oral antibiotic combined with either a topical retinoid or benzoyl peroxide should be considered if there is acne on the back or shoulders that is particularly extensive or difficult to reach, or if there is a significant risk of scarring or substantial pigment change.

Oral antibiotics are the mainstay of systemic therapy, but should not be used in isolation. Oral antibiotics should be combined with retinoids or benzoyl peroxide to make use of their useful synergistic properties. If acne returns, reuse the same drug if the previous response was satisfactory with that agent.

Topical antibiotics should not be used at the same time as oral antibiotics owing to the increased likelihood of the development of bacterial resistance.

The response to oral antibiotic treatment should be assessed after a period of about 6–8 weeks:

• Continue treatment if the drug has had a positive effect. If the person has not responded adequately, check adherence to treatment. If there has been some response, continue treatment for 3 - 6 months. Continue topical treatment after stopping. If there are significant relapses or flares, consider restarting oral treatment.
• If the person has not responded adequately, continue for a minimum of 3 months before assuming treatment is ineffective. At this stage, consider seeking specialist advice or referring to a dermatologist, and see also advice regarding co-cyprindiol for use in female patients with severe acne refractory to prolonged oral antibiotics.

Lymecycline

• See section 5.1.3 Tetracyclines

Oxytetracycline

• See section 5.1.3 Tetracyclines

Erythromycin

• See section 5.1.5 Macrolides
• Erythromycin is best reserved for patients in whom other antibiotics are unsuitable, as propionibacterial resistance to this drug is relatively common.

Trimethoprim

• See section 5.1.8 Sulfonamides and trimethoprim
• Note that trimethoprim should be reserved for the treatment of acne resistant to other antibacterials (unlicensed indication).

Minocycline is associated with a greater risk of lupus erythematosus-like syndrome and may cause irreversible pigmentation. Monitoring is required every 3 months for hepatotoxicity, pigmentation and for systemic lupus erythematosus. Due to the lack of therapeutic advantage over tetracyclines and concerns over its safety it is no longer recommended for the treatment of acne. This is in line with national guidance from NHS England (click here for more information); prescribers should not initiate minocycline for acne for any new patient.

Contraceptives

In women the use of a contraceptive which may improve the acne is an option. If the woman is experiencing worsening acne after starting a contraceptive then a switch to Gedarel 30/150 should be considered as the first line option (see section 7.3 Contraceptives).

Gedarel 30/150 should be tried first in women refractory to prolonged antibiotic therapy. Some women with moderately severe hirsuitism may also benefit as hair growth is androgen dependent.

If this treatment fails co-cyprindiol may be considered as it contains an anti-androgen. Co-cyprindiol is included in the formulary as a treatment option for moderate to severe acne (see below). It is specifically licensed for moderate to severe acne refractory to prolonged oral antibiotics. Co-cyprindiol should not be used solely for contraceptive purposes. Time to relief of symptoms is at least three months. The need to continue treatment should be evaluated periodically by the treating physician, with a view to withdrawing treatment once the skin condition has improved. The patient can then be switched to a conventional combined hormonal contraceptive with low androgenic tendencies (e.g. Gedarel 30/150), but repeat courses of co-cyprindiol may be given if the condition recurs

In severe acne, there are nodules and cysts (nodulocystic acne), as well as a preponderance of inflammatory papules and pustules. There is a high risk of scarring (or scarring may already be evident), and there is likely to be considerable psychosocial morbidity.

A patient with confluent or nodular lesions, usually with significant scarring, or significant psychological disorder irrespective of clinical grade should be referred to secondary care.

Secondary care referrals for severe nodulocystic acne patients should be as soon as possible in order to lessen the risk of scarring.

Prior to referral for isotretinoin treatment, any patients with significant mental health problems, particularly depression, will need referral for psychiatric assessment.

Any blood results available and sent with the referral letter will assist in the consultation.

Isotretinoin

• Isotretinoin may only be prescribed from the Dermatology Department under the supervision of a Consultant Dermatologist.
• On consideration that a patient may require isotretinoin, the following tests should be performed:
  • Fasting lipids (to include triglycerides)
  • LFTs
  • FBC
  • U&Es
• In female patients, consider starting the oral contraceptive pill prior to referral
• See note above regarding referral of patients with significant mental health problems.
• See section 13.6.2 Oral preparations for acne

Co-cyprindiol (Cyproterone, ethinylestradiol)

• See section 13.6.2 Oral preparations for acne