What's new in acne? An analysis of systematic reviews published in 2009-2010

Summary This review highlights clinically important findings about acne treatment identified in nine systematic reviews published or indexed in the period March 2009 to February 2010. A systematic review of dietary influences on acne suggested that a possible role of dietary factors in acne cannot be dismissed, as the studies to date have not been sufficiently large or robust. Another review looked at benzoyl peroxide, which may be enjoying a comeback because of increasing bacterial resistance to antibiotics, and suggested that there was a lack of evidence that stronger preparations were more effective than weaker ones. The same team also carried out a systematic review addressing the question of whether topical retinoids cause an initial worsening of acne. They found no evidence to suggest initial worsening of acne severity, although there was evidence of skin irritation that typically settled by 8–12 weeks. A review of oral isotretinoin and psychiatric side‐effects reinforced a possible link between the two, although it pointed out that the better‐quality primary studies were still inconclusive. An updated Cochrane Review confirmed the efficacy of combined oral contraceptives (COCs) in reducing acne lesion counts. It also found that the evidence to support COCs containing cyproterone acetate over others was very limited. Another Cochrane Review failed to show any benefit of spironolactone for acne, based on limited studies. Three reviews examined laser and light therapies, and found some evidence of superiority only for blue or blue/red light treatment over placebo light, but a general absence of comparisons against other acne treatments. Photodynamic therapy had consistent benefits over placebo but was associated with significant side‐effects and was not shown to be better than topical adapalene.