What is the pathogenesis of acne?

For a long time, the mantra of acne pathogenesis debates has been that acne vulgaris lesions develop when (supposedly largely androgen-mediated) increased sebum production, ductal hypercornification, and propionibacteria come together with local inflammatory process in the unlucky affected individual. And yet, the exact sequence, precise interdependence, and choreography of pathogenic events in acne, especially the 'match that lights the fire' have remained surprisingly unclear, despite the venerable tradition of acne research over the past century. However, exciting recent progress in this--conceptually long somewhat stagnant, yet clinically, psychologically, and socioeconomically highly relevant--everyday battlefield of skin pathology encourages one to critically revisit conventional concepts of acne pathogenesis. Also, this provides a good opportunity for defining more sharply key open questions and intriguing acne characteristics whose underlying biological basis has far too long remained uninvestigated, and to emphasize promising new acne research avenues off-the-beaten-track--in the hope of promoting the corresponding development of innovative strategies for acne management.     

What is the role of mitochondrial dysfunction in skin photoaging?

Skin ageing is a complex process involving both internal and external factors, which leads to a progressive loss of cutaneous function and structure. Solar radiation is the primary environmental factor implicated in the development of skin ageing, and the term photoaging describes the distinct clinical, histological and structural features of chronically sun‐exposed skin. The changes that accompany photoaging are undesirable for aesthetic reasons and can compromise the skin and make it more susceptible to a number of dermatological disorders. As a result, skin ageing is a topic that is of growing interest and concern to the general population, illustrated by the increased demand for effective interventions that can prevent or ameliorate the clinical changes associated with aged skin. In this viewpoint essay, we explore the role that mitochondria play in the process of skin photoaging. There is continuing evidence supporting the proposal that mitochondrial dysfunction and oxidative stress are important contributing factors in the development of skin photoaging. Further skin‐directed mitochondrial research is warranted to fully understand the impact of mitochondrial status and function in skin health. A greater understanding of the ageing process and the regulatory mechanisms involved could lead to the development of novel preventative interventions for skin ageing.     

TNFα gene polymorphisms in the pathogenesis of acne vulgaris

Inflammation plays an important role in acne pathogenesis, and pro-inflammatory cytokines are key factors in these events. Tumor necrosis factor alpha (TNFα) is a central molecule coded by a gene that shows high level of genetic polymorphisms especially in its promoter region. Single nucleotide polymorphisms (SNPs) of the TNFα gene have been shown to be associated with an increased risk to develop chronic inflammatory diseases. In order to find out if known TNFα regulatory SNPs (−1031T>C, −857C>T, −863C>A, −308G>A, −238G>A) have a role in the development of the inflammatory reactions in acne vulgaris, we analyzed our genomic collection in a retrospective case–control study using the PCR–RFLP method, and we compared the resulting genotype and allele frequencies. There were no significant differences in the observed genotype or allele frequencies between the control and acne group in case of the −1031, −863, −238 SNPs; however, the TNFα −857 minor T allele was found to act as a protective factor in our study population in acne, and a higher occurrence of the minor −308 A allele in female acne patients was also noted. Genetic variants of the TNFα gene may affect the risk of acne vulgaris. Our results can help to elucidate the molecular events leading to acne development.     

High-frequency devices effect in vitro: promissing approach in the treatment of acne vulgaris?

BackgroundAcne vulgaris is an inflammatory skin disorder leading to an impairment of quality of life and is therefore not only a cosmetic issue. Its pathogenesis is multifactorial – of particular importance is the colonization with the bacterium Propionibacterium acnes. A wide range of different treatment options exists including topical and systemic treatments depending on severity. High Frequency (HF) therapy, historically developed in the 19^th century, claims antimicrobial effects on acne skin, but solid data on its efficacy and mechanism of action is lacking.ObjectivesThe main objective of this study was to determine the efficacy of HF therapy on skin flora and P. acnes in vitro using a commercial device as well as to review studies on the mechanism of action.MethodsThe plasma source was investigated regarding electrical settings, heat, and ozone development. Bacterial skin flora, fungal isolates, and P. acnes were exposed to HF in vitro and compared to unexposed controls by evaluating the number of colonies on agar plates. To further analyze bacterial species from normal skin flora, 16S-sequencing was performed. Statistical analyses were carried out using row analysis and unpaired t-test.ResultsHF treatment led to a significant reduction of almost every bacterial and fungal species investigated in this study. Moreover, the number of colonies forming units was significantly decreased in P. acnes after HF treatment compared to controls in vitro.Study limitationsThe experiments were performed in vitro only. To assess clinical effects further in vivo experiments are necessary.ConclusionsThe results collected in this study, although in vitro, provide a mechanistic basis for HF as a complementary treatment option for patients with acne. It might also have a beneficial effect on patients with superficial infectious skin of the skin.     

What is new in the treatment of steroid-induced osteoporosis?

Glucocorticoid-induced osteoporosis (GIOP) is a serious complication resulting from long-term steroid treatment. In addition to several nonpharmacologic therapies recommended by the American College of Rheumatology, various pharmacologic therapies, such as calcium, vitamin D, hormone-replacement therapy, calcitonin, and bisphosphonates, can be used to prevent and/or treat GIOP. Bisphosphonates, which are potent inhibitors of bone resorption, are considered the most effective and first-line agents for increasing bone mineral density and decreasing the risk of fracture. Human parathyroid hormone has emerged as a promising agent for the treatment of severe GIOP when used alone or in combination with a bisphosphonate.     

What is new in the psychology of chronic itch?

Itch is often regarded as unpleasant or bothersome and is accompanied by symptoms of distress and impairments in daily life. The biopsychosocial model of chronic itch describes how psychological factors can contribute to the improvement or exacerbation of chronic itch and related scratching behaviour. Recent research underlines the important role of cognitive‐affective information processing, such as attention, affect and expectancies. This may not only play a role for acute itch states, but may particularly apply to the process of itch chronification, for example, due to the vicious cycle in which these factors shape the experience of itch. The present paper focuses on new insights into the relation between itch and the cognitive‐affective factors of attention, affect and expectancies. These factors are thought to play a possible aggravating role in itch in the long term and have received increasing attention in the recent empirical literature on maintaining and exacerbating factors for chronic physical symptoms. Possible psychophysiological and neurobiological pathways regarding these factors are discussed, as well as possible intervention methods.     

What is new in the treatment of steroid-induced osteoporosis?

Glucocorticoid-induced osteoporosis (GIOP) is a serious complication resulting from long-term steroid treatment. In addition to several nonpharmacologic therapies recommended by the American College of Rheumatology, various pharmacologic therapies, such as calcium, vitamin D, hormone-replacement therapy, calcitonin, and bisphosphonates, can be used to prevent and/or treat GIOP. Bisphosphonates, which are potent inhibitors of bone resorption, are considered the most effective and first-line agents for increasing bone mineral density and decreasing the risk of fracture. Human parathyroid hormone has emerged as a promising agent for the treatment of severe GIOP when used alone or in combination with a bisphosphonate.     

Combination blue (415 nm) and red (633 nm) LED phototherapy in the treatment of mild to severe acne vulgaris

Background and objective: Acne vulgaris represents both a challenge to the treating dermatologist and a major concern for the patient. Conventional treatments have proved inconsistent with often unacceptable side effects and high rates of recurrence. Non‐thermal, non‐laser, phototherapy for acne with a combination of blue and red light has recently attracted attention. The present study was designed to assess the efficacy of this combination phototherapy.

Methods: Twenty‐four subjects, Fitzpatrick skin types II–V, with mild to severe symmetric facial acne vulgaris were recruited for the study. Subjects were well matched at baseline in terms of both age and duration of acne. Subjects were treated over eight sessions, two per week 3 days apart, alternating between 415?nm blue light (20 minutes/session, 48?J/cm²) and 633?nm red light (20 minutes/session, 96?J/cm²) from a light‐emitting diode (LED)‐based therapy system. Patients received a mild microdermabrasion before each session. Acne was assessed at baseline and at weeks 2, 4, 8 and 12.

Results: Twenty‐two patients completed the trial. A mean reduction in lesion count was observed at all follow‐up points. At the 4‐week follow‐up, the mean lesion count reduction was significant at 46% (p = 0.001). At the 12‐week follow‐up, the mean lesion count reduction was also significant at 81% (p = 0.001). Patient and dermatologist assessments were similar. Severe acne showed a marginally better response than mild acne. Side effects were minimal and transitory. Comedones did not respond as well as inflammatory lesions.

Conclusions: Combination blue and red LED therapy appears to have excellent potential in the treatment of mild to severe acne. Treatment appears to be both pain‐ and side effect‐free.     

A microbial aetiology of acne: what is the evidence?

A microbial aetiology of acne has been suggested since the beginning of the last century. There is considerable evidence, circumstantial at best, which suggests that micro‐organisms, particularly Propionibacterium acnes, are important in the pathogenesis of acne vulgaris. However, it is still unclear whether P. acnes is actually a causal agent in the development of noninflamed or inflamed acne lesions. Based on a review of the microbiological data on normal and acne‐affected skin, we propose that P. acnes neither initiates comedogenesis nor has a role in the initiation of inflammation in inflamed acne lesions.     

Have oral contraceptives reduced the prevalence of acne? a population-based study of acne vulgaris,tobacco smoking and oral contraceptives

BACKGROUND: The prevalence of acne among adolescents appears to vary geographically. This study was therefore undertaken to describe the prevalence rate of acne among Danish adolescents and to study the possible influence of oral contraceptives (OC) and tobacco smoking on disease prevalence and severity. Both have been suggested to influence acne and are therefore potential confounders in studies of acne prevalence. METHODS: A random sample of 186 15- to 22-year-old subjects participating in a population-based study of allergic diseases in Copenhagen County were also examined for acne. Questionnaire data on demographic variables, acne problems, smoking status and use of OC were recorded, and acne was graded according to the Leeds scale. RESULTS: The prevalence of clinical acne (Leeds score >1) was 40.7% for men and 23.8% for women (odds ratio, OR, acne vs. no acne: 0.46, 95% confidence interval, CI: 0.24-0.85). Acne was perceived as a personal problem by 37.6% of all subjects, and this was associated with clinical acne (OR: 5.5, 95% CI: 2.7-10.9). The use of OC was associated with a significantly lower prevalence of acne (OR: 0.32, 95% CI: 0.11-0.86), while the use of tobacco smoking was not significantly associated with acne (OR: 0.54, 95% CI: 0.17-1.78). CONCLUSION: In congruence with recent reports from other countries, the prevalence rate of acne among adolescents was found to be lower than previously described in older reports. In this population, the use of OC was associated with a lower prevalence of acne.