There is little good quality evidence to support commonly used acne treatment regimens - and there is the potential for unforeseen harmful effects - claim UK and US researchers.
Their analysis in The Lancet looked at the evidence for all acne treatments currently available, including over-the-counter products, antibiotics and other treatments.
They found topical therapies such as benzoyl peroxide, retinoids, and antibiotics - when used in combination - usually improved control of mild to moderate acne, and that treatment with combined oral contraceptives can help women with acne.
Oral isotretinoin was the most effective therapy, although its use is limited to severe disease due to possible teratogenicity and other side-effects.
However, they reported little comparative evidence of acne treatments and warned prolonged use of oral antibiotics could increase resistant organisms in the community.
The researchers found little evidence to support the effects of diet, sunlight or improved hygiene.
Lead author Professor Hywel Williams, director of the centre of evidence-based dermatology at the University of Nottingham, said: ‘The large number of products and product combinations, and the scarcity of comparative studies, has led to disparate guidelines with few recommendations being evidence-based.'
The authors of the paper, published online today, concluded: ‘Almost half of recently published acne trials contain serious flaws that could be overcome by better reporting…The absence of trials with active comparators is a significant handicap to shared clinical decision making.'
‘Clinical trials of cost-effectiveness of different strategies for initial treatment and maintenance therapy of acne are needed.'
Lancet 2011; published early online August 30