Mild acne

Mild acne usually responds to topical retinoids or benzoyl peroxide, particularly if the patient is counselled the side effects of these topical preparations. (1,2)

Alternative possible preparations include (1,2,):

• anticomedomal preparations - appropriate where patient has blackheads and whiteheads but few inflamed lesions:
  • topical retinoid preparations eg adapalene 0.1% once daily (adapalene should be used in preference to other topical retinoids (such as tretinoin and isotretinoin))
    
    
    • comedolytic effects
      • treatment of choice for comedonal acne; they have an anti-inflammatory effect as well as decreasing inflammatory lesions indirectly by preventing comedone formation
      • patients should be advised apply a thin 'pea-sized' amount to any area affected by acne and continue until lesions clear
        • application should be at bedtime - this because retinoids are inactivated by light
          
          
    • side effects include erythema, desquamation, occasional hypo- or hyper- pigmentation, and sensitisation of the skin to sunlight. Topical retinoids should be avoided during pregnancy and breastfeeding
      • women should be warned of the potential risk of teratogenicity and should not use topical retinoids if attempting to conceive
      • the majority of patients develop a mild dermatitis, with redness and scaling of the face after a few days - however this may be controlled by reducing the amount used or the frequency of application
        • adapalene is less irritating than other agents and also has anti-inflammatory properties (2)
          
          
  • azelaic acid is an alternative anticomedonal preparation to topical retinoids
    • azelaic acid may also improve post-inflammatory hyperpigmentation (2)
      
      
  • salicyclic acid is another alternative to topical retinoids for comedomal acne (3)
    
    
• preparations targetting Propionibacterium acnes (P. acnes) and inflammation - where the patient has papulopustular acne (comedomes and some pustules and papules):
  • benzoyl peroxide 2.5-10% once daily - a potent oxidising agent with antibacterial and keratolytic properties e.g. benzamycin (R) gel. Main adverse effects are bleaching of clothes, transient skin irritation, and occasional allergic contact dermatitis. This drug may be used long term in conjunction with oral antibiotics for moderate acne vulgaris
    • the use of benzoyl peroxide does not induce P. acnes resistance
      
      
  • azaleic acid 20% twice daily - also an alternative to benzyl peroxide but is reputed to cause less irritation
    • azelaic acid has antimicrobial as well as anticomedonal properties
    • often recommended as a second-line therapy (3)
• topical antibiotics e.g. clindamycin 1% twice daily, erythromycin 2% and 4% with zinc acetate 1.2% twice daily - useful in mild to moderate acne and acne which is resistant to benzoyl peroxide
  • most useful when inflammatory lesions predominate
  • addition of benzoly peroxide to preparations with topical antibiotics reduces risk of development of bacterial resistance (3)
  • topical antibiotics are useful for mild to moderate acne when used with topical retinoids (2) - this is because the use of topical antibiotics as single agents should be avoided because of the risk of development of antimicrobial resistance, which can cause treatment failure

A follow-up after 6 weeks is advised to assess the effect of treatment and compliance. If treatment was successful continue with maintenance doses. If unsuccessful, alternative drugs should be considered (2).

NICE suggest: (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 (2)

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

Notes:

• topical salicylic acid and abrasive agents may be used during pregnancy
• if treatment is felt to be necessary in pregnancy then topical benzoyl peroxide and topical erythromycin are considered safe. Oral erythromycin should not be used. (4)
• if papulopustular acne then consider the use of a topical retinoid (or alternatively azelaic acid) at night for treatment of comedomes - in addition to specific therapy for papulopustular acne

Reference:

1. European Dermatology Forum. EDF guidelines and consensus statements​. 2016 [internet publication].

2. NICE (May 2023). Acne vulgaris: management

3. Liu H et al. Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha-hydroxy acid) for acne. Cochrane Database Syst Rev. 2020 May 1;5:CD011368.

4. Fan H et al. Associations between macrolide antibiotics prescribing during pregnancy and adverse child outcomes in the UK: population based cohort study. BMJ. 2020 Feb 19;368:m331.