Online first: Need to know - Acne

02 Oct 07

1

Women and girls with acne usually want to use skin care products like cleansers and moisturisers, and often use make-up to cover up their acne. What advice do you give for skincare?

The pathogenesis of acne in part relates to excess sebum secretion and comedone formation. Comedones are thought to arise from hypercornification of the duct epithelium in sebaceous follicles. Many components of cosmetics have been previously reported as being comedogenic.

Traditional advice has been to avoid using cosmetics and emollients altogether. If the patient feels strongly about using an emollient then a water-based product is usually recommended.

Young girls with acne are sometimes depressed with problems of self image, which can lead to social isolation. Preventing such a patient from using light make-up can impair their quality of life further. It’s important to emphasis that acne is not caused by dirt or lack of hygiene and excessive washing or use of cleansing solutions should be discouraged. Washing the face once daily with soap and water should be adequate.

The organism associated with acne (Propionibacterium acnes) tends to flourish in a greasy environment – another reason to discourage patients from using oil-based emollients and other acne products.

Is it reasonable to co-prescribe oral and topical antibiotics? If so should one use the same or different antibiotic to prevent resistance developing? Guidelines advise against using different antibiotics topically and orally but some dermatologists seem to do this anyway.

There is evidence to support combination of oral antibiotics and topical retinoids or benzoyl peroxide. If this combination proves ineffective and the patient has moderate to severe acne, then referral to secondary care is reasonable as the patient may require treatment with systemic isotretinoin.

Co-prescription of oral and topical antibiotics seems unlikely to confer any additional benefit over oral antibiotics alone but the combination does have a place in the treatment of inflammatory acne, but we advise patients to use topical antibiotics for short periods or alternate them with topical benzoyl peroxide or retinoid preparations.

Most dermatologists accept that using different classes of oral and topical antibiotics in the same patient simultaneously leads to antibiotic resistance and is therefore not recommended.

2

What is your approach to oral antibiotics? Does oral erythromycin/trimethoprim work? My impression is that it doesn’t. Is there any value in cycling different antibiotics?

A randomised controlled trial1 comparing oral erythromycin and oral tetracycline found them to be equally effective. Most dermatologists would use a tetracycline as first-line treatment, but erythromycin is preferred in women as it is safe in pregnancy.

Minocycline is expensive and should not be used first line because of safety concerns2. Doxycycline is associated with photosensitivity. All the tetracyclines are associated with benign intracranial hypertension and alternatives may be considered in patients at risk such as the obese.

As a rough guide most patients will see 20% improvement at two months, 60% improvement at six months and so on. Patients should be warned about the slow improvement otherwise they may think the treatment is ineffective and stop using it.

In practice, it seems reasonable to discontinue an antibiotic if no improvement has been seen after three months, and change to an alternative antibiotic for a further three months before referring to a specialist dermatologist for systemic isotretinoin therapy.

Sometimes, failure to respond to standard antibiotic therapy is due to the development of gram-negative folliculitis, which can also occur in patients on isotretinoin therapy. High-dose trimethoprim – 300mg twice a day – is the antibiotic of choice in these situations.

3

What is your treatment ladder for bothersome acne younger teens/preteens? What treatment advice do you give to improve compliance?

Broadly speaking, mild acne should be treated with topical measures alone. This should usually comprise a topical retinoid and a topical anti-inflammatory/antimicrobial such as benzoyl peroxide.

In resistant cases or moderate acne oral antibiotic therapy should be started. Young female patients may benefit from the use of contraceptive pills like Dianette or Yasmin, as acne is androgen mediated. Patients with severe acne, unresponsive acne, or acne that is likely to result in scarring should be referred to secondary care for consideration of treatment with oral isotretinoin.

Compliance is often an issue with topical retinoids. Mild erythema and irritation are very common with these agents and their absence might even suggest non compliance. Patients should be reassured at their first consultation that this is likely to occur and does not imply an adverse reaction. If patients are unable to tolerate the topical retinoid we suggest they try using it on alternate days or every third day, thereby building up their tolerance.

It is sometimes helpful to describe the pathogenesis of acne using diagrams as understanding how treatments work may improve adherence and discourage the use of greasy moisturisers.

4

What is the youngest age that you would consider prescribing co-pyrindiol? Is it acceptable to continue co-pyrindiol medium to long term for older patients whose acne relapses if it is discontinued? Which contraceptive pills other than co-pyrindiol are acne friendly?

Acne tends to start in early adolescence in most females and one would therefore advise the use of co-pyrindiol only once regular menstruation has been established. co-pyrindiol contains ethinyloestradiol and the anti-androgen cyproterone acetate.

Older females are at risk of thromboembolism due to the oestrogen content, and therefore we suggest the use of spironolactone for its anti-androgenic effect as an alternative. Patients should be advised to use non-hormonal contraception or stop the drug should they become pregnant due to the risk of feminisation of a male foetus.

If patients are unable to tolerate co-pyrindiol then a combination of ethinylestradiol and drospirenone is an alterative.

Parents of young girls with acne are frequently reluctant to start the contraceptive pill because of fears about sexual activity or due to religious and cultural restraints. From a medical perspective there is no reason why a girl in her early teens with established menstrual cycles should not be treated with co-pyrindiol. Explanation of the role of these specific contraceptive pills in the treatment of acne to a patient and parent may help to allay any concerns.

5

Would you treat acne in black skin any differently, such as use topical retinoids earlier?

The main problem with treating acne in black or pigmented skin is the risk of developing post-inflammatory hyperpigmentation. This may be disfiguring and in severe cases can persist for years, so systemic treatment is justifiable at an early stage in this group of patients. Azelaic acid is the preferred topical agent as it reduces pigment in post-inflammatory hyperpigmentation.

A topical retinoid should generally be used in most patients with acne but in weaker concentrations, particularly where comedones are predominant. Retinoids are known to cause a degree of irritation in almost all patients which may worsen the post-inflammatory hyperpigmentation.

Patients with pigmented skin are also at substantially increased risk of developing keloid scars. If this is thought to be a likely outcome, early referral for consideration of isotretinoin may be appropriate.

6

Where do the newer topical agents fit in?

Adapalene is a new synthetic topical retin-oid and has been found to have equal efficacy to the older topical retinoids. Importantly it causes less irritation and has a quicker onset of action. Adapalene may be worth trying in patients who are unable to tolerate the more conventional topical retinoids.

Newer combined topical therapies like Benzaclin (5% benzoyl peroxide/1% clindamycin) and Zineryt (1.2% zinc acetate/3% erythromycin) are considered more effective than single preparations alone.

7

GPs tend to stick to topical agents and oral antibiotics or use co-pyrindiol to treat acne. For treatment failures, what other options are reasonable in primary care?

Treatment failure in acne should prompt questions about compliance, particularly with topical treatment. Antibiotic therapy should be given for at least three months before considering it to be ineffective if there is no response. A combination of ethinylestradiol and drospirenone can be substituted if the patient is intolerant or unresponsive to co-pyrindiol.

Spironolactone is unlicensed for this indication but has been used in the treatment of female acne, usually prescribed in secondary care.

Physical modalities such as comedone extraction and light electrocautery may be used if available but should only be used by those experienced in these techniques. Patients who have acne resistant to the conventional treatment should be referred to a specialist dermatologist in primary or second- ary care for consideration of isotretinoin therapy.

8

When is referral to a dermatologist indicated to consider isotretinoin therapy? If moderately severe acne recurs some time after successful with isotretinoin treatment would it be reasonable to refer earlier rather than waiting until failure of oral antibiotics and so on?

Systemic isotretinoin is indicated for the treatment of severe acne and two uncommon variants of acne, nodulo-cystic and acne conglobata.

There are several circumstances in which it is used for patients with moderate rather than severe acne such as in patients with a tendency to scarring and those who are significantly psychologically disturbed. But it needs to be given with caution under supervision in view of the tendency to cause depression in some individuals.

Isotretinoin is undoubtedly the most effective available treatment for acne and has transformed the management of severe and treatment resistant cases. The response to therapy is often dramatic with excellent results, so patients are unlikely to accept a recurrence, however mild. But in these cases a second course of isotretinoin is probably not justifiable.

Often oral antbiotics combined with topical measures is all that is required and it is important to remind patients that the response to treatment can be slow (see above).

In some female patients acne persists into the late 20s or even 30s. These patients are frequently treated with multiple courses of isotretinoin and in a few cases receive continuous low-dose isotretinoin. Spironolactone offers another option.

9

There has been a lot of publicity in the lay press around using lasers for acne treatment which is available privately. How useful is this?

Lasers are occasionally used in the treatment of acne scarring. Their role in active acne is limited and not confirmed. Atrophic scarring has been treated with resurfacing using the CO2 laser and the Er:YAG laser. Patient expectations are often unrealistic and before embarking on a course of treatment it should be explained that although most patients will see some improvement, scarring once present cannot be completely eliminated.

Furthermore, laser resurfacing would be inappropriate for certain types of scarring such as deep icepick scars which may require punch excision. Hypertrophic and keloid scarring can be treated with the 585nm pulsed dye laser.

More recently fractional photothermolysis has been used in acne scarring. This is thought to be associated with less morbidity and is effective in treating the post-inflammatory erythematous macules often seen in acne.

Another more recently introduced treatment is the use of intense pulsed light. This is thought to work by reducing the population of propionibacterium acnes and decreasing sebum excretion. The licensing laws regarding this treatment are less restrictive and therefore it has been widely used by beauticians. But one needs to be careful when treating pigmented skin as the treatment can result in scarring and post-inflammatory hyperpigmentation which may result in litigation.

Dr Shernaz Walton is a consultant dermatologist and honorary clinical senior lecturer at Hull and East Yorkshire Hospitals NHS trust and Hull York Medical School.

Dr Tom Oliphant and Dr Lyndsey Paul are specialist registrars in dermatology at Princess Royal Hospital, Hull.