From new findings in acne pathogenesis to new approaches in treatment.

Acne is a chronic disease of the pilosebaceous unit which is most common during adolescence. Four factors are believed to play a key role in the development of acne lesions: excess sebum production, disturbed keratinization within the follicle, colonization of the pilosebaceous duct by Propionibacterium acnes, and the release of inflammatory mediators into the skin. Consequently, in order to effectively and rapidly reduce acne lesions, treatments need to address as many of these underlying factors as possible. Currently, about half of patients have poor adherence to acne treatments. To overcome this limitation, treatments need to be developed which are well tolerated by patients, and easy for them to use, handle and apply. Topical monotherapies for acne such as retinoids and antimicrobials by themselves have a restricted range of actions against the pathogenic factors of acne. Instead, the Global Alliance to Improve Outcomes in Acne Group recommends combination therapy with a topical retinoid and an antimicrobial agent as the preferred approach for almost all acne patients. The principal advantage of such combinations is that they target more of the underlying pathogenic factors of acne than individual monotherapies and this results in faster and more complete clearing of acne lesions. Fixed-dose combinations are also more convenient than applying two medications separately, which leads to improved adherence with the regimen. By normalizing desquamation, the retinoid component of these combinations allows entry of the antimicrobial agent into the pilosebaceous unit resulting in faster clearance of P. acnes. In conclusion, topical retinoid/antimicrobial fixed-dose combinations represent a rational approach for the treatment of acne. They should be considered as the cornerstone of acne management and should be used much more in the future.