Merec bulletin: vol10 n08

Contents: The treatment of acne vulgaris: an update The treatment of acne vulgaris: an update
While acne vulgaris affects 80%
of adolescents, it can also occur
later in life.1 It may lead to
* The main aims of acne treatment are to reduce the scarring or hyperpigmentation
number of lesions, reduce the impact of psychological and substantial disfigurement.2
Acne sufferers are also more
stress and prevent scarring. Patient counselling is an likely to be depressed or anx-
important part of disease management.
ious.1 This Bulletin discusses
the general approach to acne
* Treatment should be started as early as possible with management and considers
patients reassessed every two to three months initially.
recent issues surrounding
treatment. It will not attempt
A response may take months and in some cases to evaluate every possible
treatment may need to be continued for several years.
drug combination in acne.
* Early referral of patients with severe acne, for treatment by a dermatologist, may help to prevent scarring.
What causes acne?
* Mild acne should initially be treated with topical agents. Drug choice depends on whether comedonal or inflammatory lesions predominate. Benzoyl
peroxide or a topical retinoid are first choice agents,
sebum production and keratinousdebris cause a blockage of depending on tolerance, formulation and cost.
the pilosebaceous duct. Thisproduces a lesion called a * Oral antibiotics should be added to topical therapy
in moderate to severe acne. Tetracycline or
oxytetracycline are first choice agents as they are
(whitehead). Some comedonesevolve into inflammatory lesions effective and inexpensive. An adequate dose of an oral antibiotic should be given for at least three months before deciding a patient has failed to respond.
Inflammation may be causedby proliferation of the anaerobe * Minocycline and doxycycline have not been shown to Propionibacterium acnes.3Diet (e.g. chocolate) or poor skin be more effective than tetracycline or oxytetracycline cleansing do not worsen acne.1
and are more expensive. As reports of P. acnesresistance to minocycline are rare, it may be tried inpatients who fail to repond to first choice agents.
How should acne be managed?
* Erythromycin is best reserved for patients in whom other antibiotics are unsuitable, as propionibacterial resistance to this drug is relatively common.
management of acne requires anunderstanding of the cause, the Clindamycin and erythromycin
topical antibiotics. Tetracycline
Limitations of evidence
and isotretinoin10 to be aseffective as tretinoin. However, evidence for azelaic acid and
nicotinamide, their place in
compared benzoyl peroxide
gel for four weeks) and tretinoin
(0.1% cream, not available in theUK) in 147 patients with acne Choice of topical agent
Topical retinoids or benzoyl
peroxide are first choice agents
benzoyl peroxide is the topical
agent of choice. The place in
therapy of topical antibiotics is
How should mild acne be treated?
not well defined. Some specialistsrecommend using a topical Mild acne consists of open and
Topical benzoyl peroxide is an
(see table 1). Patients with mild
How should moderate to severe
While topical antibiotics reduce
acne be treated?
numbers of P. acnes within hairfollicles, their precise mechanism Moderate acne encompasses
The topical retinoids (vitamin A
derivatives), tretinoin,
isotretinoin and adapalene
Severe acne also includes
tretinoin causes a low-grade
Oral antibiotics are the
mainstay of systemic therapy.
• P. acnes resistance to antibiotics has been associated with a poor treatment • In 1996, a GP study of 1,000 skin swabs taken from acne patients found that 25% of swabs had strains of P. acnes which were resistant to antibiotics.
• Most data on resistance relate to in vitro measurements and are difficult to interpret in terms of clinical effect. Minocycline is unstable in bacteriological culture medium and so measurement of resistance to minocycline is unreliable. Reported resist- • Most tetracycline resistant strains of P. acnes are cross-resistant to doxycycline.
Most erythromycin resistant strains are cross-resistant to clindamycin.
Measures to minimise antibiotic resistance
• Do not prescribe antibiotics if a non-antibiotic topical preparation will suffice.
tetracycline or oxytetracycline
•. Use adequate doses of antibiotics.
• Avoid concomitant oral and topical use of antibiotics from different classes.
• Do not continue treatment for longer than necessary (but give an adequate course Minocycline (100mg daily, in
• If acne returns, reuse the same drug if the previous response was satisfactory with doxycycline (100mg daily) are
more expensive (see table 2)
• Stress to patients the importance of good compliance.
and have not been shown to bemore effective than tetracycline Table 1. Antibiotic resistance.8,12-14
or oxytetracycline. However, theymay be useful when compliance table 1). There is evidence that
P. acnes.20 This is also the case for Minocycline has been the
effects, minocycline should be
reserved for patients who fail
to respond to tetracycline
years or more.8 An adequate
or oxytetracycline.8,15
dose of oral antibiotic should
resistant strains of P. acnes.
be given for at least three
months before deciding a
patient has failed to respond.
Anti-androgen therapy may
menstrual flare.2 Dianette
prescribe oral isotretinoin.
Erythromycin (500mg twice
Treatment duration and referral
As it is highly teratogenic, womenof childbearing age should use Other reasons for referralinclude: scarring, pigmentation, Table 2. Comparative costs of some oral antibiotics for acne.
(Prices are based on Chemist & Druggist and the Drug Tariff, October 1999).
Cost of 28 days therapy
acne or unpleasant side-effectsfrom current acne therapy.
Tetracycline - 500mg twice a day
Patient counselling
Oxytetracycline - 500mg twice a day
Doxycycline - 100mg once a day
likely timescale for improvementand that treatment may be needed Vibramycin Acne Pack capsules 50mg Vibramycin-D dispersible tablets 100mg Patients should avoid abrasive
Minocycline - 100mg daily in one or two divided doses
cleansers and vigorous scrub-
bing, as this may worsen acne
by provoking inflammation.3
Minocin MR modified-release capsules 100mg Erythromycin - 500mg twice a day
acceptable to the patient,otherwise they may not be used.
Generally, gels and solutions are
sensitive or dry skin. Creams are
'greasy'. Lotions are thinner
N.B. Doses quoted are those recommended in the BNF for acne treatment.
Conclusions
Sykes NL, Webster GF. Acne: a review of opt- imum treatment. Drugs 1994; 48(1): 59-70
20 Eady EA, Bojar RA, et al. The effects of acne September 1999; 38
peroxide and erythromycin on skin carriage of Cunliffe WJ, Poncet M, et al. A comparison of erythromycin-resistant propionibacteria. Br J the efficacy and tolerability of adapalene 0.1% Dermatol 1996; 134: 107-113
gel versus tretinoin 0.025% gel in patients with 21 Chalker DK, Shalita A, et al. A double-blind study of the effectiveness of a 3% erythromycin and 5% benzoyl peroxide combination in the 139(Suppl 52): 48-56
10 Dominguez J, Hojyo MT, et al. Topical isotretin- Dermatol 1983; 9: 933-936
oin vs. topical retinoic acid in the treatment of 22 Draelos ZK. Patient compliance: enhancing acne vulgaris. Int J Dermatol 1998; 37: 54-55
clinician abilities and strategies. J Am Acad 11 Lyons RE. Comparative effectiveness of benzoyl Dermatol 1995; 32: S42-S48
peroxide and tretinoin in acne vulgaris. Int J Dermatol 1978; 17: 246-251
12 Eady EA. Bacterial resistance in acne.
Useful information sources
Dermatology 1998; 196: 59-66
13 Cunliffe W, Eady A. GP acne survey: results Acne Support Group
and recommendations. Prescriber 1996; 7(4):
14 Cunliffe WJ. Rapid resolutions in the primary care management of acne: Round table series 62, The Royal Society of Medicine Press Ltd, 15 Ferner RE, Moss C. Minocycline for acne: first References
line antibacterial treatment of acne should be Chu TC. Acne and other facial eruptions.
with tetracycline or oxytetracycline. BMJ 1996; Medicine 1997; 25(9): 30-33
'acne.Key Facts'
Brown SK, Shalita AR. Acne vulgaris. Lancet 16 Knowles SR, Shapiro L, Shear NH. Serious 1998; 351: 1871-1876
adverse reactions induced by minocycline.
Leyden JJ. Therapy for acne vulgaris. N Engl J Arch Dermatol 1996; 132: 934-939
Med 1997; 336: 1156-1162
17 Gough A, Chapman S, et al. Minocycline Anon. Topical antibiotics for acne. Drug Ther induced autoimmune hepatitis and systemic Bull 1992; 30: 33-35
Healy E, Simpson N. Acne vulgaris. BMJ 1994; 1996; 312: 169-172
308: 831-833
hyperpigmentation. Lancet 1997; 349: 400
Date of preparation: September 1999
drug treatment in acne. Dermatology 1998; 19 Guillebaud J. Contraception your questions 196: 119-125
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