In recent years, significant progress has been made in the understanding of the pathophysiological mechanisms of acne and the role of Propionibacterium acnes. With this review, the authors aim to provide an update on the current understanding of the role of P. acnes in the development of acne lesions and analysing the potential implications for future treatments. A total of 188 articles published between January 1980 and March 2013 were searched using key words such as acne, P. acnes, microbiology, Corynebacterium acnes, acne vulgaris, pathogenesis, antibiotic, vaccination and a combination of those key words. From those articles, 77 were analysed in depth. Recent data confirm that P. acnes has a strong proinflammatory activity and targets molecules involved in the innate cutaneous immunity, keratinocytes and sebaceous glands of the pilosebaceous follicle and leads to the development of comedones. Furthermore, the profile of its different strains may differ between healthy subjects and acne patients. The better understanding of the role of P. acnes may allow for new perspectives in the treatment of acne. Novel therapies should target molecules implicated in the activation of innate immunity, including toll-like receptors, protease-activated receptors and topical antimicrobial peptides; the latter may be an alternative to topical antibiotics and thus a solution for limiting bacterial resistance induced by topical macrolides. Vaccines may also be promising. However, the most appropriate candidate remains to be selected.

The GEA Scale is a global scale validated both on photographs and acne patients which can be used either in clinical research or by the dermatologist in his office.

Acne can have an important psychological impact. We surveyed 852 adolescents aged 12-25 years about their knowledge of acne and its treatment in a non-medical context. The study involved a questionnaire administered to callers to a youth telephone helpline in France. Callers were categorized into those who currently had acne, those who had had acne previously, and those who had never had acne. Most respondents (66.2%) had experienced acne symptoms, which were mild in 50.2% of cases and severe in 16% of cases. Often, acne had been long-lasting (>12 months in 49.6% of cases). Many thought that gender, excess weight, eating dairy products, and physical activity did not influence acne, and that frequent washing could improve acne. Eating chocolate and snacks, smoking cigarettes, sweating, not washing, touching/squeezing spots, eating fatty foods, using make-up, pollution, and menstruation were thought to worsen acne. The majority (80.8%) did not believe acne to be a disease, but rather a normal phase of adolescence, yet 69.3% agreed it should be treated. There was a preference for topical vs. systemic treatment. Many (38.6%) of the respondents with acne had not consulted a physician. Almost two-thirds of respondents wanted more information about acne. Providing more information about acne might increase the likelihood of them consulting a physician and getting better treatment for the condition.

Background: Cutibacterium acnes has been identified as one of the main triggers of acne. However, increasing knowledge of the human skin microbiome raises questions about the role of other skin commensals, such as Staphylococcus epidermidis, in the physiopathology of this skin disease. Summary: This review provides an overview of current knowledge of the potential role of S. epidermidis in the physiopathology of acne. Recent research indicates that acne might be the result of an unbalanced equilibrium between C. acnes and S. epidermidis,according to dedicated interactions. Current treatments act on C. acnesonly. Other treatment options may be considered, such as probiotics derived from S. epidermidis to restore the naturally balanced microbiota or through targeting the regulation of the host’s AMP mediators. Key Messages: Research seems to confirm the beneficial role of S. epidermidis in acne by limiting C. acnes over-colonisation and inflammation.