Moderate acne

A single topical treatment can be used in moderate acne but a combination of two topical drugs is usually advantageous. Moderate comedonal acne with minimal inflammation may respond to topical retinoids alone (1)

UK guidance recommends a topical retinoid, benzoyl peroxide, and oral antibiotic for the treatment of moderate to severe acne vulgaris (2)

• topical antibiotic plus benzoyl peroxide - used as first line therapy
• topical retinoid plus benzoyl peroxide - may cause skin irritation
• topical retinoid plus a topical antibiotic
• azelaic acid (alone) - used in patients with skin irritation caused by other treatment methods (2)

Oral antibiotics remain a mainstay of treatment. They are indicated in: (2)

• topical treatment failure
• moderate acne of the back and shoulders
• patients with a risk of scarring or substantial pigment changes

If using an oral antibiotic, a tetracycline, such as lymecycline or doxycycline (for a maximum course of 3 months). (2)

• to reduce the risk of antibiotic resistance developing - always co-prescribe a topical retinoid (if not contraindicated) e.g. adapalene, or benzoyl peroxide

Alternative antibiotic treatments include:

• macrolides e.g. erythromycin
  • less useful because increased levels of Propionobacterium acnes (P. acnes) resistance to erythromycin among acne patients

Monitoring antibiotic treatment:

• review after 6 weeks to assess the treatment effect and compliance, and continue for the full duration if it is effective.
• if there is no improvement after 3 months (unable to tolerate side effects or acne worsens while on treatment) then a switch to an alternative antibiotic is indicated
• failure to respond to two different 3 month courses of antibiotics, or the development of acne scarring, is an indication for referral to a dermatologist for consideration of treatment with isotretinoin

Alternatives to oral antibiotics in women:

• combined oral contraceptives
  
  
  • can be considered as an alternative to systemic antibiotics in women (if not contraindicated)
  • used in combination with topical agents
  • third and fourth generation combined oral contraceptives are generally preferred
    
    
• oral antiandrogen (2):
  • co-cyprindiol (Dianette®) or other ethinylestradiol/cyproterone acetate containing products
    • licensed only for women with severe acne that has not responded to antibacterials and for treatment of acne in women with moderately severe hirsutism
    • risk of venous thromboembolism is higher in women taking co-cyprindiol than a low-dose COC - should not be used solely as a contraceptive and use of an additional hormonal contraceptive with co-cyprindiol is contraindicated (2)
    • whilst on treatment the patient should be evaluated regularly by a clinician and the patient advised to be vigilant for signs and symptoms of VTE
    • should be discontinued 3 months after acne has been controlled
    • for the individual product - consult the Summary of Product Characteristics and consider UK Medical Eligibility Criteria for Contraceptive Use

Review after 6 weeks to assess the treatment effect and compliance, and continue for the full duration if it is effective.

NICE suggest specific treatment options below (2):

NICE state in the case of polycystic ovary syndrome then consider adding ethinylestradiol with cyproterone acetate (co-cyprindiol) or an alternative combined oral contraceptive pill to their acne treatment (2).

First-line treatment for acne vulgaris:

Offer people with acne a 12-week course of 1 of the following first-line treatment options, taking account of the severity of their acne and the person's preferences, and after a discussion of the advantages and disadvantages of each option (see table):

• a fixed combination of topical adapalene with topical benzoyl peroxide for any acne severity
• a fixed combination of topical tretinoin with topical clindamycin for any acne severity
• a fixed combination of topical benzoyl peroxide with topical clindamycin for mild to moderate acne
• a fixed combination of topical adapalene with topical benzoyl peroxide, together with either oral lymecycline or oral doxycycline for moderate to severe acne
• topical azelaic acid with either oral lymecycline or oral doxycycline for moderate to severe acne

Treatment choices for mild to moderate and moderate to severe acne vulgaris

Consider topical benzoyl peroxide monotherapy as an alternative treatment to the options in table, if:

• these treatments are contraindicated, or
• the person wishes to avoid using a topical retinoid, or an antibiotic (topical or oral)

For people with moderate to severe acne who cannot tolerate or have contraindications to oral lymecycline or oral doxycycline, consider replacing these medicines in the combination treatments in table with trimethoprim or with an oral macrolide (for example, erythromycin)

Factors to take into account at review

• Review first-line treatment at 12 weeks and:
  • assess whether the person's acne has improved, and whether they have any side effects
  • in people whose treatment includes an oral antibiotic, if their acne has completely cleared consider stopping the antibiotic but continuing the topical treatment
  • in people whose treatment includes an oral antibiotic, if their acne has improved but not completely cleared, consider continuing the oral antibiotic, alongside the topical treatment, for up to 12 more weeks
• only continue a treatment option that includes an antibiotic (topical or oral) for more than 6 months in exceptional circumstances. Review at 3-monthly intervals, and stop the antibiotic as soon as possible
• be aware that the use of antibiotic treatments is associated with a risk of antimicrobial resistance
• if a person's acne has cleared, consider maintenance options (see linked item)
• if acne fails to respond adequately to a 12-week course of a first-line treatment option and at review the severity is
  • mild to moderate: offer another option from the table of treatment choices (see table below)
  • moderate to severe: and the treatment did not include an oral antibiotic: offer another option which includes an oral antibiotic from the table of treatment choices (see table below)
  • moderate to severe, and the treatment included an oral antibiotic: consider referral to a consultant-led dermatology team
• If mild to moderate acne fails to respond adequately to 2 different 12-week courses of treatment options, consider referral to a consultant dermatologist-led team. (2)

Notes:

• trimethoprim is highly effective in the treatment of acne and is increasingly used by dermatologists - however it may cause an allergic rash in 5 per cent of patients
• if a patient with moderate acne and nodular lesions fails to respond to two courses of antimicrobial therapy (each for three months) in combination with a topical retinoid and benzoyl peroxide then s/he should be referred for consideration for oral isotretinoin therapy (2)
  
  hormonal cause of acne should be suspected in women if there are premenstrual flare-ups or sudden onset of acne or related signs (2)
  
  
• acne may be exacerbated by oral progesterone only contraceptives or progestin implants with androgenic activity
  
  
• minocycline in the management of acne vulgaris
  • not recommended for use in acne as it is associated with an increased risk of drug­ induced lupus, skin pigmentation and hepatitis
  • patients receiving long-term minocycline should be monitored for the development of antinuclear antibody (2)
• if required antibiotic courses can be repeated if flare ups in the future (2)

The respective summary of product characteristics must be consulted before prescribing any of the drugs mentioned above.

Reference:

1. Harper JC et al. Efficacy and tolerability of a novel tretinoin 0.05% lotion for the once-daily treatment of moderate or severe acne vulgaris in adult females. J Drugs Dermatol. 2019 Nov 1;18(11):1147-54.

2. National Institute for Health and Care Excellence. Acne vulgaris: management. Dec 2023 [internet publication].