Editor—Although the review and commentary by Webster et al on the management of acne contain good sense, the opinions presented do not fully reflect the evidence base or the risks associated with antibiotics.1
Webster promotes the use of antibiotics in the routine management of even mild acne when there is considerable global effort to limit antimicrobial prescribing to reduce resistance in key pathogens (www.cdc.gov/drugresistance/actionplan/html).2 The extended antibiotic courses used in treating acne exert immense selective pressure on commensal flora,3 and, as Webster says, resistance in Propionibacterium acnes is compromising efficacy. Antibiotics should therefore be stopped as soon as no further improvement is evident and not routinely used for maintenance; alternatives exist that have similar efficacy and have preventive action—for example, topical retinoids.4
Webster says that acne resistant to conventional regimens can be managed by increasing the frequency of topical and the dose of oral treatment. With antibiotics, such strategies have not been proved to increase efficacy,4 but they will increase selective pressure. In addition, higher strength benzyl peroxide is in general no more effective than lower strength preparations but is associated with more irritation.4
No evidence from randomised controlled trials supports the use of second generation tetracyclines (doxycycline and minocycline) over (oxy)tetracycline for acne.4 We disagree that ciprofloxacin and cotrimoxazole should be used. Ciprofloxacin given orally shows rapid selectivity, which promotes resistance,5 and quinolones are not recommended in adolescents because of the associated risk of arthropathy. The sulphamethoxazole component of co-trimoxazole is associated with significant side effects, and the combination has not been proved to be more effective than trimethoprim alone.
Poyner and Cunliffe's suggestion to tell patients to expect little improvement in the first month and 20% improvement a month thereafter is incompatible with Webster's recommendation that failure to respond in four to eight weeks should prompt a substantial change of treatment. Given the large variability in clinical response between patients, they may simply be advised that improvement might not be immediately apparent and to return after six to eight weeks for review.
These issues illustrate the urgent need for better research into the treatment of acne and a re-evaluation of fact from myth. A recent systematic review of acne trials published by the US Agency for Healthcare Research and Quality found reliable evidence of efficacy in only 14 of 250 comparisons (www.ahrq.gov/clinic/evrptfiles.htm#acne). Robust evidence that answers the key questions necessary to prescribers is imperative given the overall burden of the disease both for individual patients and for healthcare resources.
References
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