Search

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.

Background and objective Many acne grading methods exist; however, there is no agreed-upon standard. Our objective was to create and validate a reproducible acne assessment scale for rating the severity of juvenile facial acne suitable for use in France and Europe. Methods The scale we created described the different types of acne lesions in a manner similar to global assessment scales used in clinical trials. The scale was then validated by seven expert dermatologists in the field of acne [the Global Evaluation Acne (GEA) group] first on 34 photographic cases of Caucasian acne patients and second by clinical examination of 22 acne patients. Results There was good agreement in Investigators’ assessments of acne both on photographs and patients (R = 0.8057; P

Background Acne is a highly heterogeneous disorder with respect to its regional involvement, demographics, lesion types and response to treatment. Homogeneous patient groups must therefore be created before measuring the severity of acne and interpreting the results of therapeutic trials. The individualization of ‘juvenile acne of the face’ is a first step in this direction. Methods Based on textbooks, major reviews of acne and a ′Medline′ literature search, we identified four key points to delineate sub groups of acne patients. Result ‘Juvenile acne of the face’ is defined by four main clinical criteria: (1) age (from puberty to age 25 years), (2) site (face), (3) lesion type (polymorphous), (4) absence of a causal factor. Other subgroups of ‘true’ acne are listed with their distinctive characteristics. Non-acne follicular diseases (i.e. without sebum retention) are listed. Discussion We chose ‘juvenile acne of the face’ to define the first homogeneous group of patients because it is the most frequent form of acne and the target of most acne drugs. It has a sufficiently uniform prognosis to devise a functional and reproducible severity rating scale with the aim of facilitating the evaluation and comparison of therapeutic methods. Conclusion The next step in our work will be to elaborate severity scales which are dedicated to a single type of acne.

Background The three-grade acne classification (mild, moderate, severe) is widely used to define the licensed indications of acne treatments, and for therapeutic decision-making in clinical practice, but its reproducibility has never been assessed. Methods Ten photographs of facial acne were scored independently by eight experts using the three-grade acne classification. We conducted a descriptive analysis of the results, based on graphical representation of the scores for each photograph. Results Inter-observer agreement on acne severity based on the three-grade acne classification was very poor. Conclusion The classical three-grade acne classification is poorly reproducible. A new rating tool accompanied by a clinical description of each severity level would be extremely useful.

A 28-year-old man presented with a histiocytic sarcoma of a very uncommon origin, as it had developed for several years like a benign cutaneous histiocytosis resembling generalized eruptive histiocytoma before becoming acute, with nodal and massive pulmonary involvement. Despite various chemotherapies, the patient died within 8 months. Skin biopsies showed histiocytic proliferation in the dermis and node biopsies showed histiocytic proliferation with a sinusoidal pattern. Immunohistochemical analysis, performed on paraffin-embedded sections, demonstrated strong labeling of tumoral cells for CD68 and moderate labeling for CD3 and CD4. CD30 labeling was negative. S-100 protein was positive on a Langerhans' cell reactive subpopulation. Electron microscopy confirmed the histiocytic nature of malignant cells and showed cytoplasmic inclusions such as regularly laminated bodies, dense bodies and pleomorphic inclusions. No Birbeck granules were seen. A gene rearrangement study of T-cell receptor gamma and immunoglobulin heavy chain genes showed a germline configuration. Histiocytic sarcoma is an extremely rare true histiocytic malignancy, the existence of which has been recently debated since it has often been mistaken in the past for large cell lymphomas. Such a deceptive onset as benign cutaneous histiocytosis has not been described in the literature to our knowledge.