An assessment of the efficacy of blue light phototherapy in the treatment of acne vulgaris

Background Acne vulgaris is a common skin condition that affects 8 out of 10 people. It varies from mild to severe, and different treatments target various aspects of the disease. Propionibacterium acnes, one of the culprits involved in the pathogenesis of acne vulgaris, is the main target of all major medical treatments used. Studies conducted in recent years have shown favorable effects within the visible light spectrum for the treatment of acne vulgaris. Objective In this study, we have evaluated the use of intense blue light within the spectral range of 415–425 nm (peak 420 nm) in the treatment of acne vulgaris. Methods Twenty‐one patients with mild to moderate facial acne were treated with blue light phototherapy. All patients were given 14‐min treatment sessions twice a week for 4 weeks. Acne severity was assessed using the Leeds Technique for grading and lesion counts. Disability was assessed using the Dermatology Life Quality Index (DLQI). In addition, standard digital and cross‐polarized light photographs were taken and graded by a blinded evaluator. Visual analog scale (VAS) scores and cultures for P. acnes were carried out before starting the treatment and upon completion of the treatment. Results Significant improvement was achieved in the Leeds Acne Grade (P = 0.001). The inflammatory (P = 0.001) and noninflammatory (P = 0.06) lesion counts also improved significantly. A similar change was noted in the DLQI (P = 0.001); a degree of significance was also achieved in the patients’ and the investigators’ VAS scores (P = 0.01 and P = 0.001, respectively). P. acnes colony counts failed to show a significant decrease at the end of the treatment and remained almost constant (P = 0.660). Conclusions We believe that blue light does appear to have some role in the management of acne and may be beneficial for the treatment of a select group of mild to moderate acne patients.     

An increased incidence of Propionibacterium acnes biofilms in acne vulgaris: a case-control study

Summary Background Acne vulgaris is a disorder of the sebaceous follicles. Propionibacterium acnes can be involved in inflammatory acne. Objectives This case–control study aimed at investigating the occurrence and localization of P. acnes in facial biopsies in acne and to characterize the P. acnes phylotype in skin compartments. Methods Specific monoclonal and polyclonal antibodies were applied to skin biopsies of 38 patients with acne and matching controls to localize and characterize P. acnes and to determine expression of co‐haemolysin CAMP factor, a putative virulence determinant. Results Follicular P. acnes was demonstrated in 18 (47%) samples from patients with acne and eight (21%) control samples [odds ratio (OR) 3·37, 95% confidence interval (CI) 1·23–9·23; P = 0·017]. In 14 (37%) samples from patients with acne, P. acnes was visualized in large macrocolonies/biofilms in sebaceous follicles compared with only five (13%) control samples (OR 3·85, 95% CI 1·22–12·14; P = 0·021). Macrocolonies/biofilms consisting of mixed P. acnes phylotypes expressing CAMP1 were detected in both case and control samples. Only four samples tested positive for the presence of Staphylococcus spp. and fungi were not observed. Conclusions We have for the first time visualized different P. acnes phylotypes in macrocolonies/biofilms in sebaceous follicles of skin biopsies. Our results support the hypothesis that P. acnes can play a role in the pathogenesis of acne as acne samples showed a higher prevalence of follicular P. acnes colonization, both in terms of follicles containing P. acnes and the greater numbers of bacteria in macrocolonies/biofilms than in control samples.     

What is the role of antimicrobial peptides (AMP) in acne vulgaris?

Acne vulgaris is the most common disorder of the pilosebaceous unit leading to inflamed skin characterized by the formation of comedones, papules, pustules and scarring. There is increasing evidence that the abundance of Propionibacterium acnes (P. acnes) in the inflamed acne lesions triggers inflammation. Therefore, in addition to treatment with retinoids, the use of antimicrobial agents has been established as a treatment option for acne. This indicates that antimicrobial mechanisms to control the growth of P. acnes may have an important influence on the severity of inflammatory acne. One import antimicrobial innate defense system comprises the production of antimicrobial peptides (AMP), small molecules with a broad spectrum of antimicrobial activity as well as immunomodulatory properties. Although the role of AMP in acne is still emerging, there is increasing evidence that AMP may be of importance in acne. The aim of this viewpoint is to provide some hypotheses about the potential function of AMP in the pathogenesis of acne and to discuss potential AMP‐based therapies for the treatment of acne.     

Single nucleotide polymorphisms of toll‐like receptor‐4 protect against acne conglobata

Background Former studies have shown that Propionibacterium acnes may stimulate expression of toll‐like receptor 4 (TLR4) in keratinocytes of patients with acne vulgaris. Objective To investigate the impact of single nucleotide polumorphisms (SNPs) of the TLR4 gene in acne vulgaris. Methods Genomic DNA was isolated from 191 patients with acne vulgaris and 75 healthy controls. Asp299Gly and Thr399Ile SNPs were defined after cutting of the PCR products by restriction enzymes. Sebum of lesions was cultured for P. acnes. Results No differences in SNP allele frequencies were found between patients and healthy controls. 46.5% of carriers of wild‐type alleles were suffering from acne conglobata compared with 28.6% of carriers of SNP alleles (P = 0.040). After adjusting for gender, family history of acnes, intake of any therapy and skin isolation of P. acnes, carriage of TLR4 gene SNPs was the only independent variable linked with a protective role against acne conglobata (OR = 0.269, P = 0.014). No differences were found in the amount of pro‐inflammatory cytokines released by peripheral blood mononuclear cells isolated from patients with acne conglobata carrying only wild‐type alleles and SNP alleles. Conclusions Carriage of gene SNPs is protective against the development of acne conglobata even in the presence of P. acnes.     

Effects of 420‐nm intense pulsed light in an acne animal model

Background Blue light in the 400–420 nm range has been shown to reduce the levels of Propionibacterium acnes (P. acnes) in the skin. P. acnes has been postulated to be a critical trigger for inflammatory acne. Thus, treatment with 420 nm‐intense pulsed light should reduce inflammatory activity in acne. Aim To evaluate the clinical and histological effects of 420 nm‐intense pulsed light treatment on acne in animal model. Method Inflammation acne animal model was constructed by intradermal injection of P. acnes of rat auricular. Levels of tumour necrosis factor alpha (TNF‐α) and matrix metalloproteinase 2 (MMP‐2), markers of inflammation implicated in acne, were assessed in treated and untreated animals by immunohistochemistry and quantitative polymerase chain reaction (PCR). Result Treatment with 420 nm intense pulsed light led to marked improvement after 6 biweekly treatments. Immunohistochemistry and PCR showed that TNF‐α and MMP‐2 levels correlated with the extent of acneiform activity and were reduced by treatment with 420 nm light. Conclusion A 420‐nm intense pulsed light may exert its beneficial effects on inflammatory acne by reducing the levels of P. acnes and secondarily reducing inflammation induced by the bacteria.     

Interleukin‐10 secretion from CD14+ peripheral blood mononuclear cells is downregulated in patients with acne vulgaris

Background Acne is a common chronic inflammatory dermatosis of the pilosebaceous unit. It is characterized by seborrhoea, comedone formation and an inflammatory response consistent with defective cellular immunity to Propionibacterium acnes. Objectives The objective of this study was to investigate the immune reactivity of patients with acne compared with healthy controls by examining the response of peripheral blood mononuclear cells (PBMCs) to stimulation with P. acnes. Particular focus was placed upon measuring the production of interleukin (IL)‐10, which has an established immunoregulatory role. Patients and methods Venous blood was collected from 47 patients with acne and 40 age‐ and sex‐matched healthy controls with no prior history of acne. PBMCs were cultured and their cytokine response to P. acnes investigated. Results Proinflammatory IL‐8 and tumour necrosis factor (TNF)‐α secretion from PBMCs was higher in patients with acne when stimulated with P. acnes. In contrast, a statistically significant reduction in PBMC secretion of anti‐inflammatory IL‐10 in patients with acne was identified. The impaired production of IL‐10 by PBMCs from patients with acne was confined to CD14+ cells presumed to be monocytes. The ability of CD14 cells from patients with acne to phagocytose P. acnes bacteria was also observed to be defective but the addition of exogenous IL‐10 to PBMC cultures restored phagocytic activity. Conclusions These data suggest that patients with acne have a proinflammatory cytokine milieu and crucially are unable to contain early inflammatory changes due to a specific defect in immunosurveillance, namely low monocyte IL‐10 production. Our observations raise the possibility that acne therapeutics might profitably target IL‐10 both as a regulator of proinflammatory cytokines and in augmenting the CD14+ cell phagocytic response.     

Different strains of Propionibacterium acnes modulate differently the cutaneous innate immunity

Acne is a chronic inflammatory illness of the pilosebaceous follicle where innate immunity plays a central role. In acne, the density of Propionibacterium acnes is increased in the pilosebaceous unit. We hypothesized that the severity of acne is not only dependent on the proliferation of P. acnes but also dependent on the pro‐inflammatory potential of P. acnes strains and consequently constitutes potential triggering factor for acne scarring. We investigated pro‐inflammatory potential of five different strains of P. acnes and P. avidum in skin explants and the preventive effect of zinc gluconate. The expression of immune markers was studied by immunohistochemistry, RT‐qPCR and ELISA. P. acnes strains modulate differently the expression of immune markers both at gene and at protein levels. P. acnes type III had the highest pro‐inflammatory potential by up‐regulating the expression of PAR‐2, TNF‐alpha, MMP‐13 and TIMP‐2, whereas P. avidum had the weakest by up‐regulating only MMP‐13 and TIMP‐2. Preincubation of zinc gluconate, which is a modulator of innate immunity, down‐regulates the expression of most immune markers induced by P. acnes, PAR‐2, TIMP‐2, up‐regulates MMP‐1, TIMP‐1. Our results demonstrate that different P. acnes strains have different inflammatory potential targeting markers of cutaneous innate immunity, and that inflammatory potential can be down‐regulated by zinc gluconate. As such, the inflammatory potential of P. acnes strains on acne skin may influence the severity of inflammatory acne lesions and scars.     

Salicylic acid treats acne vulgaris by suppressing AMPK/SREBP1 pathway in sebocytes

Acne vulgaris is a prevalent cutaneous disease characterized by a multifactorial pathogenic process including hyperseborrhea, inflammation, over‐keratinization of follicular keratinocytes and Propionibacterium acnes (P acnes) overgrowth. Salicylic acid (SA), a beta‐hydroxy acid, is frequently used in the treatment of acne. SA has been found to decrease skin lipids and to possess anti‐inflammatory properties. However, few studies have elucidated the mechanisms and pathways involved in such treatment of acne. In this study, we initially investigated the anti‐acne properties of SA in human SEB‐1 sebocytes. Treatment with SA decreased sebocyte lipogenesis by downregulating the adenosine monophosphate‐activated protein kinase (AMPK)/sterol response element‐binding protein‐1 (SREBP‐1) pathway and reduced inflammation by suppressing the NF‐κB pathway in these cells. Salicylic acid also decreased the cell viability of SEB‐1 by increasing apoptosis via the death signal receptor pathway. Subsequently, histopathological analysis of a rabbit ear acne model after application of SA for three weeks confirmed that SA suppressed the levels of cytokines and major pathogenic proteins around acne lesions, which supports the mechanisms suggested by our in vitro experiments. These results initially clarified that therapeutic activities of SA in acne vulgaris treatment could be associated with the regulation of SREBP‐1 pathway and NF‐κB pathway in human SEB‐1 sebocytes.     

Topical acne treatments in Europe and the issue of antimicrobial resistance

Acne vulgaris (acne) is a chronic inflammatory disease of the sebaceous gland, characterized by follicular hyperkeratinization, excessive colonization by Propionibacterium acnes (P. acnes) as well as immune reactions and inflammation. Despite an armamentarium of topical treatments available including benzoyl peroxide, retinoids and azelaic acid, topical antibiotics in monotherapies, especially erythromycin and clindamycin, are still used in Europe to treat acne. This intensive use led to antimicrobial‐resistant P. acnes and staphylococci strains becoming one of the main health issues worldwide. This is an update on the current topical acne treatments available in Europe, their mechanism of action, their potential to induce antimicrobial resistance and their clinical efficacy and safety.     

Heat‐killed Propionibacterium acnes is capable of inducing inflammatory responses in skin

Abstract: The etiology of acne is a complex process, and acne is one of the most common skin disorders affecting millions of people. The pathogenesis of acne is closely associated with the bacterium, Propionibacterium acnes which was previously known as Corynebacterium parvum. Both viable and non‐viable P. acnes/C. parvum have been shown to induce an immunostimulatory effect in vivo, suggesting that even dead bacteria continue to activate an inflammatory response. Acne treatments with lasers or devices, induce a bactericidal effect through heat generation which may not address the immunogenic activity of P. acnes and the resulting acne inflammation. Therefore, we sought to determine whether killed P. acnes is capable of inducing an inflammatory response and therefore could be a contributing factor in acne. Direct heat treatment of P. acnes cultures with temperatures ranging from 50°C to 80°C reduced P. acnes viability. Both viable and heat‐killed P. acnes activated the p38 MAP kinase and its downstream substrate Hsp27. Stimulating keratinocytes with normal and heat‐inactivated P. acnes resulted in an induction of proinflammatory nitric oxide and IL‐8 production. Thus killed P. acnes is capable of inducing inflammation in skin suggesting that therapies that have both bactericidal and anti‐inflammatory effects may result in a more effective treatment of patients with acne than treatments that are bactericidal alone.     

Antibiotic resistance of microbial strains isolated from Korean acne patients

Over several decades, topical and systemic antibiotics have been the mainstay of treatment for acne vulgaris. The widespread and long‐term use of antibiotics in the treatment of acne has resulted in the spread of resistant bacterial strains and treatment failure. We aimed to examine the bacteriology of acne vulgaris and to evaluate its susceptibility to the antibiotics widely used for acne in Korea. We examined the species of bacteria aerobically and anaerobically isolated from 100 Korean acne patients. Among the bacteria isolated, Staphylococcus epidermidis (36 patients) was the most common, followed by Propionibacterium acnes (30 patients). Eleven strains of P. acnes (36.7%) and 25 strains of S. epidermidis (69.4%) were resistant to one or other of the antibiotics tested. A higher proportion of P. acnes isolates were resistant to clindamycin (30%) and erythromycin (26.7%), than to any other antibiotics tested (P = 0.0003). Some S. epidermidis isolates were resistant to tetracycline and doxycycline in addition to clindamycin and erythromycin. In the previous studies, few strains of P. acnes were found to be resistant to any of the antibiotics, but this study shows that antibiotic‐resistant strains have been increasing in Korea acne patients.     

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.     

Comparative study of the bactericidal effects of indocyanine green‐ and methyl aminolevulinate‐based photodynamic therapy on Propionibacterium acnes as a new treatment for acne

Acne vulgaris is one of the most common dermatological problems, and its therapeutic options include topical and systemic retinoids and antibiotics. However, increase in problems associated with acne treatment, such as side‐effects from conventional agents and bacterial resistance to antibiotics, has led to greater use of photodynamic therapy. The purpose of this study was to compare the bactericidal effects of indocyanine green‐ and methyl aminolevulinate‐based photodynamic therapy on Propionibacterium acnes. P. acnes were cultured under anaerobic conditions; then they were divided into three groups (control, treated with indocyanine green and treated with methyl aminolevulinate) and illuminated with different lights (630‐nm light‐emitting diode, 805‐nm diode laser and 830‐nm light‐emitting diode). The bactericidal effects were evaluated by comparing each group's colony‐forming units. The cultured P. acnes were killed with an 805‐nm diode laser and 830‐nm light‐emitting diode in the indocyanine green group. No bactericidal effects of methyl aminolevulinate‐based photodynamic therapy were identified. The clinical efficacy of indocyanine green‐based photodynamic therapy in 21 patients was retrospectively analyzed. The Korean Acne Grading System was used to evaluate treatment efficacy, which was significantly decreased after treatment. The difference in the efficacy of the 805‐nm diode laser and 830‐nm light‐emitting diode was not statistically significant. Although the methyl aminolevulinate‐based photodynamic therapy showed no bactericidal effect, the indocyanine green‐based photodynamic therapy has bactericidal effect and clinical efficacy.     

What's new in acne? An analysis of systematic reviews published in 2011–2012

This review summarizes important clinical developments in acne vulgaris identified from 17 systematic reviews published between February 2011 and August 2012. Regarding causes, Demodex mites have been shown to be associated with both acne vulgaris and rosacea, although it is unclear if their eradication improves either disease. Some weak evidence has emerged that suggests a possible link between dairy produce and acne, which warrants further research. With reference to the effects of acne, there is good evidence that acne negatively affects quality of life, self‐esteem and mood in adolescents. Acne is also associated with an increased risk of anxiety, depression and suicidal ideation, highlighting the importance of asking patients with acne directly about psychological issues in order to identify those who might benefit from early psychiatric support. Regarding treatment, there seems to be no additional benefit to using higher strengths of benzoyl peroxide, and lower strengths such as 2.5% have fewer side effects. Despite earlier concerns of increased mortality in those using topical tretinoin for skin cancer prevention, a systematic review on this topic has not found any convincing evidence of a link between such non‐cutaneous events and once‐daily application of 0.02–0.05% tretinoin. Combined oral contraceptives are of benefit in both inflammatory and non‐inflammatory acne. Current surveys suggest that implementation of the pregnancy prevention programme for isotretinoin may not be stringent, and a high level of monitoring and audit is recommended. Ablative and non‐ablative laser resurfacing for the treatment of acne scars may be beneficial, but further studies with a longer follow‐up period are required.     

Heterogeneity and antibiotic resistance in Propionibacterium acnes isolates and its therapeutic implications: blurring the lines between commensal and pathogenic phylotypes

Acne vulgaris is a multifactorial skin disease associated with the colonization of Propionibacterium acnes. Antibiotics are a mainstay of treatment for acne, yet the emergence of resistance against the currently approved antibiotics is a serious concern. In this case report, a slow responder had multiple Propionibacterium acnes isolates with varied levels of sensitivity to the conventional antibiotics. The bacterial isolates obtained from acne samples collected from the patient were analyzed for phylogeny, and was found to be largely restricted to two different lineage patterns. Propionibacterium acnes phylotype IA1, which is considered to be pathogenic, displayed clindamycin sensitivity, but phylotype IB, which is associated with commensals, exhibited high clindamycin resistance. Sensitivity analysis revealed uniform resistance to macrolides, but susceptibility to tetracycline and nadifloxacin. These results implicate Propionibacterium acnes in the pathophysiology of acne vulgaris, although the lines between commensal and pathological phylotypes may be blurred. Switching the patient to a combination of minocycline and nadifloxacin resulted in a significant improvement in the clinical lesions. Such a science‐driven judicious selection of antibiotics can minimize the probability of development of resistance, and might be the way forward in the treatment of acne.     

Significant reduction of inflammation and sebaceous glands size in acne vulgaris lesions after intense pulsed light treatment

Intense pulsed light (IPL) has been used for years in treatment of acne vulgaris. However, quantitative evaluation of histopathological changes after its use as a sole therapy was poorly investigated. Accordingly, this study aims to objectively evaluate inflammatory infiltrate and sebaceous glands in acne vulgaris after IPL. Twenty‐four patients of acne were treated with six IPL sessions. Clinical evaluation was done at 2 weeks after last session by counting acne lesions. Patient satisfaction using Cardiff Acne Disability Index (CADI) was recorded at baseline, 2 weeks and 3 months after IPL. Using histopathological and computerized morphometric analysis, quantitative evaluation of inflammatory infiltrate and measurement of surface area of sebaceous glands were performed for skin biopsies at baseline and 2 weeks after last session. After IPL, there was significant reduction of all acne lesions especially inflammatory variety with significant decrease of CADI score at 2 weeks and 3 months after IPL (p < .05). Microscopically, there was significant decrease in density of inflammatory infiltrate and surface area of sebaceous glands (p < .05). So, IPL is fairly effective therapy in acne vulgaris especially inflammatory variety. The results suggest that IPL could improve acne lesions through targeting both inflammation and sebaceous glands.     

Systemic antibiotic therapy of acne vulgaris

Background: Inflammatory, medium to severe acne vulgaris is treated with systemic antibiotics worldwide. The rationale is an effect on Propionibacterium acnes as well as the intrinsic anti‐inflammatory properties of these antibiotics. Although there are no correlations between the number of P. acnes and the severity of the disease, associations between the degree of humoral and cellular immune responses towards P. acnes and the severity of acne have been reported. Exact data on practical use of these compounds, such as differential efficacy or side effects are unavailable.A summary of currently available studies is presented. Methods: The data of studies of systemic antibiotic therapy of acne vulgaris up to 1975, the summary of literature in English up to 1999, a systematic review of minocycline from 2002 as well as the data of randomized controlled studies published and listed in Medline thereafter were reviewed. Results: Tetracyclines [tetracycline 1 000 mg daily, doxycycline 100 (?200) mg daily, minocycline 100 (?200) mg daily, lymecycline 300 (?600) mg] and erythromycin 1 000 mg daily are significantly more effective than placebo in the systemic treatment of inflammatory acne.The data for tetracycline are best founded. Clindamycin is similarly effective. Co‐trimoxazole and trimethoprim are likely to be effective. Clear differences between the tetracyclines or between tetracycline and erythromycin cannot be ascertained. The data for the combination with topical treatments [topical benzoyl peroxide (BPO) or retinoids] suggest synergistic effects.Therefore systemic antibiotics should not be used as monotherapy. In case of similar efficacy, other criteria, such as pharmacokinetics (doxycycline, minocycline, lymecycline have longer half‐lives than tetracyclines), the rate of side‐effects (tetracycline: side effect‐rate ～4 % mild side effects; erythromycin: frequent gastrointestinal complaints; minocycline: rare, but potentially severe hypersensitivity reactions; doxycycline: dose‐dependent phototoxic reactions), the resistance rate [percentage of resistant bacteria higher with erythromycin (～ 50 %) than with tetracycline‐therapy (～ 20 %)], and the costs of therapy have to be taken into account. Conclusions: The systemic antibiotic therapy of widespread papulo‐pustular acne not amenable to a topical therapy is effective and well‐tolerated. In general therapy can be carried out for 3 months and should be combined with BPO to prevent resistance.     

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.     

Treatment of acne vulgaris with fractional radiofrequency microneedling

Fractional radiofrequency microneedling is a novel radiofrequency technique that uses insulated microneedles to deliver energy to the deep dermis at the point of penetration without destruction of the epidermis. It has been used for the treatment of various dermatological conditions including wrinkles, atrophic scars and hypertrophic scars. There have been few studies evaluating the efficacy of fractional radiofrequency microneedling in the treatment of acne, and none measuring objective parameters like the number of inflammatory and non‐inflammatory acne lesions or sebum excretion levels. The safety and efficacy of fractional radiofrequency microneedling in the treatment of acne vulgaris was investigated. In a prospective clinical trial, 25 patients with moderate to severe acne were treated with fractional radiofrequency microneedling. The procedure was carried out three times at 1‐month intervals. Acne lesion count, subjective satisfaction score, sebum excretion level and adverse effects were assessed at baseline and at 4, 8 and 12 weeks after the first treatment as well as 4, 8 and 12 weeks after the last treatment. Number of acne lesions (inflammatory and non‐inflammatory) decreased. Sebum excretion and subjective satisfaction were more favorable at every time point compared with the baseline values (P < 0.05). Inflammatory lesions responded better than non‐inflammatory lesions (P < 0.05). Adverse effects such as pinpoint bleeding, pain and erythema were noted, but were transient and not severe enough to stop treatment. Fractional radiofrequency microneedling is a safe and effective treatment for acne vulgaris.     

Skin microbiome differences relate to the grade of acne vulgaris

The skin microbiome plays important roles in the pathogenesis and development of acne. We aimed to investigate the facial skin microbiome of acne and microbiome differences related to different grades of acne. Skin swabs from nine healthy controls and 67 acne patients were collected, and the skin microbiomes were analyzed using 16S rRNA gene sequencing. Compared with healthy controls, acne patients harbored significantly altered skin microbiomes. The skin microbiomes of patients with grade 1–3 acne were similar, but patients with grade 4 acne showed a significantly different skin microbiome compared with grade 1–3 acne, including increased alpha diversity and increased proportions of four Gram‐negative bacteria (Faecalibacterium, Klebsiella, Odoribacter and Bacteroides). In conclusion, acne patients harbored an altered skin microbiome, and more significant dysbiosis was found in patients with grade 4 acne (severe acne). Our findings may provide evidence for the pathogenic mechanisms of acne and microbial‐based strategies to avoid and treat acne, especially grade 4 acne.