Current concepts of the pathogenesis of acne: implications for drug treatment

Research Progress of Dihydroquercetin in the Treatment of Skin Diseases

Skin is a barrier to maintaining the stability of the human environment and preventing the invasion of pathogens. When skin tissue is exposed to the external environment, it will inevitably develop defects due to trauma, injury, burns, ulcers, surgery, and chronic diseases. Rapid skin repair is the key to reducing infection, relieving pain, and improving quality of life. Dihydroquercetin is a kind of flavonoid that has a wide range of pharmacological activities and can improve skin repair, skin inflammation, skin cancer, and so on. In this paper, the application of dihydroquercetin in medical dressings and the research progress in the treatment of skin-related diseases are reviewed, so as to provide reference for further developing dihydroquercetin as a drug for the treatment of skin diseases.

Oxidative stress and metabolic syndrome in acne vulgaris: Pathogenetic connections and potential role of dietary supplements and phytochemicals

Acne vulgaris is a highly prevalent skin condition caused by androgen-induced elevated sebum secretion, abnormal keratinization, bacterial colonization, and inflammation. Current research indicates a link between acne vulgaris and the metabolic syndrome, a group of disorders that includes obesity, insulin resistance, hypertension, and dyslipidemia. This link is thought to be modulated by excessive concentrations of oxidative stress markers and chronic inflammation, which are included in the pathophysiological mechanisms shared by both conditions. Excessive generation of reactive oxygen species damages cellular components and initiates an inflammatory response, hence promoting the development of both disorders. The current narrative review focuses on the molecular implications of inflammatory, hormonal, and environmental factors in the acne-metabolic syndrome correlation. Furthermore, it outlines the current state of knowledge related to the phyto-therapeutic approach to these conditions as an adjuvant strategy to allopathic treatment, but future multicenter and larger-scale research studies are needed establish new algorithms to be included in the future management of patients with these conditions.

Sun exposure, a relevant exposome factor in acne patients and how photoprotection can improve outcomes

BACKGROUND

Acne pathophysiology includes a complex interaction among inflammatory mediators, hyperseborrhea, alteration of keratinization and follicular colonization by Propionibacterium acnes.

AIMS

To describe the impact of the exposome on acne and how photoprotection can improve outcomes.

METHODS

A narrative review of the literature was carried out; searches with Google Scholar and Pubmed from January 1992 to November 2022 were performed. The keywords used were "acne," "sunscreens," "photoprotection," "cosmetics," "cosmeceuticals," "pathogenesis," "etiology," "exposome," "sunlight," "stress," "lack of sleep," "diet," "postinflammatory hyperpigmentation," "pollution," "exposome," "ultraviolet radiation," and "visible light."

RESULTS

Environmental factors such as solar radiation, air pollution, tobacco consumption, psychological stress, diverse microorganisms, nutrition, among others, can trigger or worsen acne. Solar radiation can temporarily improve lesions. However, it can induce proinflammatory and profibrotic responses, and produce post-inflammatory hyperpigmentation and/or post-inflammatory erythema. While photoprotection is widely recommended to acne patients, only four relevant studies were found. Sunscreens can significantly improve symptomatology or enhance treatment and can prevent post-inflammatory hyperpigmentation. Furthermore, they can provide camouflage and improve quality of life. Based on acne pathogenesis, optimal sunscreens should have emollient, antioxidant and sebum controlling properties.

CONCLUSIONS

The exposome and solar radiation can trigger or worsen acne. UV light can induce post-inflammatory hyperpigmentation/erythema, and can initiate flares. The use of specifically formulated sunscreens could enhance adherence to topical or systemic therapy, camouflage lesions (tinted sunscreens), decrease inflammation, and reduce the incidence of post-inflammatory hyperpigmentation/erythema.

Nanoparticles loaded with pharmacologically active plant-derived natural products: Biomedical applications and toxicity

Pharmacologically active natural products have played a significant role in the history of drug development. They have acted as sources of therapeutic drugs for various diseases such as cancer and infectious diseases. However, most natural products suffer from poor water solubility and low bioavailability, limiting their clinical applications. The rapid development of nanotechnology has opened up new directions for applying natural products and numerous studies have explored the biomedical applications of nanomaterials loaded with natural products. This review covers the recent research on applying plant-derived natural products (PDNPs) nanomaterials, including nanomedicines loaded with flavonoids, non-flavonoid polyphenols, alkaloids, and quinones, especially their use in treating various diseases. Furthermore, some drugs derived from natural products can be toxic to the body, so the toxicity of them is discussed. This comprehensive review includes fundamental discoveries and exploratory advances in natural product-loaded nanomaterials that may be helpful for future clinical development.

Zinc and Zinc Transporters in Dermatology

Zinc is an important trace mineral in the human body and a daily intake of zinc is required to maintain a healthy status. Over the past decades, zinc has been used in formulating topical and systemic therapies for various skin disorders owing to its wound healing and antimicrobial properties. Zinc transporters play a major role in maintaining the integrity of the integumentary system by controlling zinc homeostasis within dermal layers. Mutations and abnormal function of zinc-transporting proteins can lead to disease development, such as spondylocheirodysplastic Ehlers-Danlos syndrome (SCD-EDS) and acrodermatitis enteropathica (AE) which can be fatal if left untreated. This review discusses the layers of the skin, the importance of zinc and zinc transporters in each layer, and the various skin disorders caused by zinc deficiency, in addition to zinc-containing compounds used for treating different skin disorders and skin protection.

The SII reflects inflammation in acne vulgaris, but fails to determine categorical severity

BACKGROUND

Systemic Immune Inflammation Index (SII; calculated by multiplying neutrophil-lymphocyte ratio and platelet count) has been investigated as a marker of inflammation.

AIM

we aimed to investigate the relationship of SII with acne severity and whether it can be used as a practical method in determining categorical acne severity.

MATERIALS AND METHODS

All participants (aged 15-30 years, n = 212) were prospectively evaluated with acne severity scales, including the Global Acne-Grading System (GAGS), the Comprehensive Acne Severity Scale (CASS), and the Patient-centered Acne Severity Scale. Patients were grouped according to GAGS: healthy individuals (n = 53), patients with mild (n = 44), moderate (n = 86), and severe acne (n = 29). Patients' hemogram data obtained simultaneously with the physical examination were used in the analysis.

RESULTS

The groups were statistically similar in terms of age and gender, both according to acne severity and current lesion types. The neutrophil count was significantly higher in patients with nodulocystic acne than in acne patients with non-inflammatory lesions or healthy individuals (p: 0.022). SII was significantly higher in acne patients with nodulocystic lesions than in individuals with milder lesions, both non-inflammatory and inflammatory (p = 0.004). SII was weakly significantly correlated with GAGS, CASS, and the number of nodulocystic lesions (r = 0.164, p = 0.018; r = 0.147, p = 0.034; r = 0.222, p = 0.001). However, none of the hemogram parameters, including SII, differed in classifying acne severity according to GAGS (p > 0.05).

CONCLUSIONS

Systemic immune inflammation index may be a new and reliable inflammatory marker to reflect the severity of inflammation, especially in patients with nodulocystic acne, although it is not useful in categorizing acne severity.

Non-conventional therapeutical approaches to acne vulgaris related to its association with metabolic disorders

The ever-increasing frequency of metabolic syndrome (MetS) is still a major challenge of the public health care system, worldwide. In recent years, researchers have been drawn to the uncommon (at first look) link between skin illnesses and MetS. Because of the pro-inflammatory mechanisms and insulin resistance (IR) that are upregulated in metabolic syndrome, many skin disorders are correlated to metabolic dysfunctions, including acne vulgaris. A comprehensive understanding of the link between MetS and acne vulgaris may contribute to the development of new treatment strategies. The current review focuses on dietary and therapeutic interventions and assesses the effect of various approaches such as improving diet by avoiding certain food products (i.e., milk and chocolate) or increasing the intake of others (i.e., food products rich in omega-3 fatty acids), metformin administration, therapy with plant extracts, plant essential oils, and probiotic supplementation on the improvement of certain acne vulgaris severity parameters. These therapeutic approaches, when combined with allopathic treatment, can improve the patients' quality of life.

Pharmacological Effects of Centella asiatica on Skin Diseases: Evidence and Possible Mechanisms

The medicinal herb Centella asiatica (L.) Urban known as gotu kola has been reported to exhibit a wide range of pharmacological activities. In particular, a significant body of scientific research exists on the therapeutic properties of preparations of C. asiatica or its triterpenes in the treatment of skin diseases. The present study is aimed to provide a comprehensive overview of the beneficial effects of C. asiatica on skin diseases. Peer-reviewed articles on the potent dermatological effects of C. asiatica were acquired from PubMed, Web of Science, Scopus, ScienceDirect, and SciFinder. This review provides an understanding of pharmacological studies which confirm the potent dermatological effects and underlying molecular mechanisms of C. asiatica. This medicinal plant and its triterpenes include asiaticoside, madecassoside, and their aglycones, asiatic acid and madecassic acid. These compounds exert therapeutic effects on dermatological diseases such as acne, burns, atopic dermatitis, and wounds via NF-κB, TGF-β/Smad, MAPK, Wnt/β-catenin, and STAT signaling in in vitro and in vivo studies. However, additional rigorously controlled long-term clinical trials will be necessary to confirm the full potential of C. asiatica as a therapeutic agent.

[Acne]

Acne vulgaris is one of the most frequent dermatological diseases with a lifetime prevalence of about 85%. The clinical spectrum shows a great variety. Key factors of pathogenesis are increased sebum production, hyperkeratinization of the follicular infundibulum, inflammatory processes, and a dysbiosis of the skin microbiome. In addition to endogenous factors (e.g., disturbances of the androgen metabolism) or other hormonal changes, exogenous factors (e.g., diet, mechanical irritation or the use of inappropriate cosmetics) can also play an important role. The clinical spectrum is broad, extending from neonatal Acne (A.) to adult A., from comedonal A. to fulminant A., from cosmetic A. to A. excoriée (skin picking disorder). The psychological effects of acne can be profound and can cause a severe reduction in quality of life. Therefore, in addition to an effective therapy with regular medical check-ups and good adherence, it is always necessary to consider psychological aspects.

Role of Molecular Hydrogen in Skin Diseases and its Impact in Beauty

In today's society, healthy skin and a beautiful appearance are considered the foundation of general well-being. The skin is the largest organ of the body and plays an important role in protecting it against various hazards such as environmental, physical, chemical, and biological hazards. These factors include mediators that lead to oxidation reactions that produce reactive oxygen/nitrogen species and additional oxidants in the skin cells. An increase in oxidants beyond the antioxidant capacity of its defense system causes oxidative stress and chronic inflammation in the body. This response can cause further disruption of collagen fibers and hinder the functioning of skin cells that may result in the development of various skin diseases including psoriasis, atopic dermatitis, and aging. In this review, we summarized the present information related to the role of oxidative stress in the pathogenesis of dermatological disorders, and its impact on physical beauty and the daily lives of patients. We also discussed how molecular hydrogen exhibits a therapeutic effect against skin diseases via its effects on oxidative stress. Furthermore, findings from this summary review indicate that molecular hydrogen might be an effective treatment modality for the prevention and treatment of skin-related illnesses.

A systematic review of N-acetylcysteine for treatment of acne vulgaris and acne-related associations and consequences: Focus on clinical studies

Acne vulgaris is one of the most common dermatologic disorders affects people of all races and ethnicities and has many adverse effects on the quality of life. The increased bacterial resistance to antibiotics has reduced the effectiveness of treatment with these agents. There is an increasing focus on the involvement of oxidative stress in the pathophysiology of acne. This study investigates the effect of N-acetylcysteine (NAC) as an antioxidant in the treatment of acne vulgaris. This systematic review was conducted through a search in databases such as Science Direct, PubMed, Scielo, and Medline using keywords including acne vulgaris, anti and NAC, and all the keywords associated with each of the subtitles. The factors affecting the occurrence and expansion of acne include increased sebum synthesis, hyperkeratinization of pilosebaceous units, colonization with Propionibacterium acnes, and increased release of inflammatory mediators and ROS. Studies have shown that glutathione stimulation following the administration of NAC increases glutathione levels for the detoxification of oxygen-free radicals. Moreover, NAC prevents the synthesis and release of inflammatory cytokines such as TNF-α, IL-8, IL-6, MP9, and IL-1β and has shown antibacterial activities against important bacteria including E. coli, S. epidermidis, Pseudomonas, and Klebsiella. This medication has anti-proliferative effects and is also used for excoriation and PCOD. The results of the present study showed the beneficial effects of using NAC in patients with acne vulgaris in terms of the disease complications and comorbidities. Given its diverse functional mechanisms, this medication can be used to treat acne and its consequences.

Acne - therapeutic challenges to the cooperation between a dermatologist and a cosmetologist

Acne vulgaris is one of the most common skin diseases in adolescence, causing a significant negative impact on the quality of life of young people who - in a large percentage of cases - do not accept their appearance. The complex pathogenesis of this disease requires appropriate preventive and curative treatment from both a dermatologist and a cosmetologist. The aim of the study was to discuss the methods currently used by dermatologists in local therapy for mild and intermediate forms of acne vulgaris, and to provide an overview of possible preventive and caring activities in the cosmetologist's office. Possible directions of cooperation between the dermatologist and the cosmetologist in the prevention of acne relapse and treatment of possible acne complications were also discussed.

Anti-acne vulgaris effects of chlorogenic acid by anti-inflammatory activity and lipogenesis inhibition

Chlorogenic acid (CGA) exhibits substantial biological function in antioxidant, antibacterial, anti-lipogenesis and anti-inflammatory activities. Increased sebum production and inflammation are considered important for the development of acne. However, the therapeutic effects of CGA on acne vulgaris remain unexplored. In this study, to assess the effects and underlying mechanisms of CGA on acne, a model of skin inflammation in ears of ICR mouse induced by living Propionibacterium acnes was used. 24 hours after 1.0 × 107 CFU, P. acnes were intradermally injected into the ears of the ICR mouse. 1, 5 and 10 mg of CGA mixed with vaseline were applied to the surface of the skin every 12 hours for 3 days. Then, skin inflammation in the ears was assessed and the change of SREBP1 and TNF-α expression was analysed after CGA treatment. The mechanisms of CGA in anti-inflammatory activity and lipogenesis were also studied in primary sebocytes and HaCaT cells. We found that CGA treatment effectively rescued ear swelling, redness and erythema skin in ears of ICR mouse induced by P. acnes and significantly downregulated the expression of inflammatory cytokines by reducing the activity of the NF-κB signalling pathway. Furthermore, CGA could inhibit lipogenesis at the protein secretion and transcription level by decreasing the AKT/mTOR/SREBP signalling pathway. Our findings suggest that CGA could become a potential alternative drug for the treatment of acne vulgaris.

Adverse events related to topical drug treatments for acne vulgaris

Introduction: Acne vulgaris is a widespread skin disease. Topical therapy is a standard treatment for mild to moderate acne. Given the complex pathophysiology of acne, various agents with complementary action are nowadays frequently combined to increase the efficacy of therapy.Area covered: This review focus on safety profile of topical agents used for the treatment of acne vulgaris, including topical retinoids, benzyl peroxide, azelaic acid, topical antibiotic, and combined agents. Data from clinical trials but also metanalyses, systematic reviews, and other secondary analyses are presented.Expert opinion: In general, topical agents used for acne vulgaris have a favorable safety profile. The most commonly reported AEs were associated with local skin irritation, usually mild to moderate in intensity, intermittent, and rarely led to the cessation of therapy. Irritative potential seems to be highest for BPO and topical retinoids. Due to the possibility of development of Cutibacterium acnes resistance, topical antibiotics should not be used in monotherapy but as a part of combination therapy. In female adolescent and adults of childbearing potential, topical retinoids should be used with caution, because they are contraindicated in pregnant females (FDA Pregnancy category) C (adapalene, tretinoin) and X (tazarotene).

The Challenge of Nanovesicles for Selective Topical Delivery for Acne Treatment: Enhancing Absorption Whilst Avoiding Toxicity

Acne is a common skin disease that affect over 80% of adolescents. It is characterized by inflammation of the hair bulb and the attached sebaceous gland. To date, many strategies have been used to treat acne as a function of the disease severity. However, common treatments for acne seem to show several side effects, from local irritation to more serious collateral effects. The use of topical vesicular carriers able to deliver active compounds is currently considered as an excellent approach in the treatment of different skin diseases. Many results in the literature have proven that drug delivery systems are useful in overcoming the toxicity induced by common drug therapies, while maintaining their therapeutic efficacy. Starting from these assumptions, the authors reviewed drug delivery systems already realized for the topical treatment of acne, with a focus on their limitations and advantages over conventional treatment strategies. Although their exact mechanism of permeation is not often completely clear, deformable vesicles seem to be the best solution for obtaining a specific delivery of drugs into the deeper skin layers, with consequent increased local action and minimized collateral effects.

Modulation of skin androgenesis and sebum production by a dermocosmetic formulation

BACKGROUND

Excessive androgenesis in the skin promotes sebaceous hyperproduction which is the onset of acne vulgaris pathogenesis. Free fatty acids and lipid accumulation in the glandular infundibulum culminates in microbiota imbalance, triggering inflammatory response and follicular hyperkeratinization.

AIMS

The purpose of this work was to present an alternative cosmetic treatment for acne skin care, focusing on the prevention of sebaceous gland dysregulation.

METHODS

Insulin-stimulated human sebocytes were treated with noncytotoxic concentrations of a DTRW cosmetic formulation. After 6 days of incubation, cell lysates were collected for testosterone, 5α-reductase, and dyhidrotestosterone (DHT) quantitation. In parallel, cells were stained with Oil Red O to measure sebum production.

RESULTS

Human sebocytes were incubated with insulin to mimic a seborrheic microenvironment with overproduction of intracellular lipids and fatty acids. Concomitant incubation of cell cultures with DRTW was able to promote a 52.97% reduction in intracellular lipid content. The anti-androgenic properties of DRTW had been proved by the reductions of testosterone (↓59.90%), 5α reductase (↓59.34%), and DHT (↓55.98%) levels in sebocyte cultures also stimulated with insulin.

CONCLUSION

The results indicate a promising action of DRTW cosmetic formulation in preventing the development of acne lesions by mechanisms involving the modulation of cutaneous androgenesis and consequently the control of sebum overproduction, considered one of the leading causes of acne.

Study of biosurfactant extract from corn steep water as a potential ingredient in antiacne formulations

Background: This is a novel work that includes the use of a biosurfactant extract obtained from corn milling industry (named BS-CSW), with antimicrobial activity, as ingredient in formulations to treat acne vulgaris. Methodology: With this purpose, it was established an incomplete experimental design with 3 independent variables, based on the concentration of non-nano zinc oxide (ZnO) (0-2%), BS-CSW (0-5%) and salicylic acid (0-2%). Results: This design allowed to obtain a theoretical model that calculates the inhibitory effect on Cutibacterium acnes (also named Propionibacterium acnes) for any formulation carried with the ingredients appointed before. It was observed a clear synergetic effect on the inhibition of C. acnes between ZnO and BS-CSW, in absence of salicylic acid. This fact allowed to reduce the concentration of ZnO, giving more ecofriendly and biocompatible formulations. Conclusions: It was observed that the biosurfactant extract, in formulations with intermediate concentration of ZnO (1%), possess an inhibitory effect on C. acnes considerably higher than ZnO alone and similar to ZnO (1%) with salicylic acid (1%). This fact demonstrates the enormous potential of this bioactive extract in antiacne formulations.

Acne treatment efficacy of intense pulsed light photodynamic therapy with topical licochalcone A, l-carnitine, and decanediol: A spilt-face, double-blind, randomized controlled trial

BACKGROUND

Depending on disease severity, standard acne treatments can vary from topical to systemic therapy. However, poor compliance caused by adverse events and antibiotic resistance is a major cause of treatment failure.

AIMS

To determine the effectiveness of photodynamic therapy (PDT) with intense pulsed light (IPL) in the treatment of acne when combined with a cream containing licochalcone A, L-carnitine and decanediol (so-called, 'active formulation') versus PDT alone.

PATIENTS/METHODS

Twenty-nine volunteers, aged 21-39 years (26 women and 3 men, mean age 29.41 ± 5.24 years), with mild to severe facial acne, were enrolled. Each subject's face sides were randomized in a split-face manner to either receive PDT (IPL with a 400-720 nm cut-off filter, at 4 sessions with two-week intervals) combined with the active formulation cream twice daily for 10 weeks on one face side; or PDT and the vehicle cream on the other side, with the same treatment protocol. Reduction in acne quantity, melanin index and erythema index were assessed 2 weeks after the second treatment (day 28), 1 week after the fourth treatment (day 49), and 1 month after the fourth treatment (day 70).

RESULTS

Compared to baseline, patients in the active formulation group demonstrated a faster onset of reduction in the number of lesions at 2 weeks after the second treatment (p=0.010 for inflammatory acne and p=0.001 for non-inflammatory acne). A significantly greater reduction in lesion count was observed in the active formulation group compared with the vehicle group at all timepoints of evaluation for noninflammatory acne (day 28, day 49, and day 70; p=0.003, 0.005 and 0.002 respectively), and at 1 month after the fourth treatment for inflammatory acne (p=0.036). Compared to the vehicle group, the melanin index of the active formulation group decreased significantly at 1 month after the fourth treatment (p=0.015).

CONCLUSION

PDT is more effective in treating acne when combined with a topical cream containing licochalcone A, L-carnitine and decanediol, than PDT alone. Significant acne reduction and improvements in post-inflammatory hyperpigmentation were observed, which offers acne patients a better therapeutic option. It is a safe and effective combination treatment for patients with moderate and severe acne.

Clinical efficacy of 0.5% topical mangosteen extract in nanoparticle loaded gel in treatment of mild-to-moderate acne vulgaris: A 12-week, split-face, double-blinded, randomized, controlled trial

BACKGROUND

Acne vulgaris is the most common inflammatory sebaceous gland disorder in young adults. The resistant strains of Propionibacterium acnes (P. acnes) are of increasing concern in the treatment of acne.

OBJECTIVES

To evaluate the efficacy of 0.5% topical mangosteen extract in nanoparticle loaded gel (containing alpha-mangostin) compared with 1% clindamycin gel for treatment of mild-to-moderate acne vulgaris.

METHODS

Patients aged 18-40 years were enrolled in this double-blinded, split-face, randomized, control study. The 2.5% benzoyl peroxide cream was applied to both sides of the faces once daily for 5 minutes and washed off. Each patient was randomly treated with the mangosteen fruit rind extract on one side and 1% clindamycin on another side of the face twice daily for 12 weeks. Treatment efficacies and side effects were evaluated on every follow-up.

RESULTS

Twenty-eight patients, 24 female (85.7%), mean ± SD age of 25.14 ± 5.8, with Global Acne Grading system (GAGs) score of 15.43 ± 5.96 were included. Mangosteen fruit rind extract significantly showed significant 66.86% and 67.05% reduction of comedone and inflammatory lesions (P < 0.001) after 12-week treatment. The improvement on both treated sides significantly showed since 2 weeks after treatment, without statistical difference between two groups. Nonetheless, the mangosteen fruit rind extract revealed significantly better improvement of clinical severity, with no severe side effects.

CONCLUSIONS

The mangosteen fruit rind extract formation could be a phytopharmaceutical medication for effective treatment of mild and moderate acne vulgaris treatment comparable to 1% clindamycin gel, with no severe side effects.

Evidence for the Important Role of Oxidative Stress in the Pathogenesis of Acne

Acne vulgaris is a common inflammatory skin disorder which is recognizable by dermatological lesions and scars. In addition to some pathogenetic factors such as hyperkeratinization, upregulated sebum secretion, and immunoinflammatory reactions, recent studies have also connected oxidative stress to the pathogenesis of acne vulgaris. In this article, we will briefly review clinical studies that interrogated alterations in oxidative stress biomarkers by a systematic search conducted in PubMed, Web of Science, and Scopus using "acne", "oxidative stress", and "reactive oxygen species" keywords. Overall, studies have shown that oxidative biomarkers (e.g. lipid peroxidation final products) are higher in acne vulgaris lesions. A significant positive correlation has also been noted between acne severity and oxidative biomarkers. In contrast, diminished levels of antioxidant enzymes (e.g. superoxide dismutase and catalase) have been observed in acne. We propose four probable mechanisms for the role of reactive oxygen species (ROS) in acne pathogenesis. We believe that ROS can contribute significantly to the acne vulgaris pathobiology via toll-like receptor (TLR), peroxisome proliferator-activated receptor (PPAR), mTOR pathway, and innate immune system, resulting in inflammation by alterations in the generation of several proinflammatory cytokines including IL-1, IL-8, and TNF-α.

Oral isotretinoin for acne

BACKGROUND

Acne vulgaris, a chronic inflammatory disease of the pilosebaceous unit associated with socialisation and mental health problems, may affect more than 80% of teenagers. Isotretinoin is the only drug that targets all primary causal factors of acne; however, it may cause adverse effects.

OBJECTIVES

To assess efficacy and safety of oral isotretinoin for acne vulgaris.

SEARCH METHODS

We searched the following databases up to July 2017: the Cochrane Skin Group Specialised Register, CENTRAL, MEDLINE, Embase, PsycINFO and LILACS. We updated this search in March 2018, but these results have not yet been incorporated in the review. We also searched five trial registries, checked the reference lists of retrieved studies for further references to relevant trials, and handsearched dermatology conference proceedings. A separate search for adverse effects of oral isotretinoin was undertaken in MEDLINE and Embase up to September 2013.

SELECTION CRITERIA

Randomised clinical trials (RCTs) of oral isotretinoin in participants with clinically diagnosed acne compared against placebo, any other systemic or topical active therapy, and itself in different formulation, doses, regimens, or course duration.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 31 RCTs, involving 3836 participants (12 to 55 years) with mild to severe acne. There were twice as many male participants as females.Most studies were undertaken in Asia, Europe, and North America. Outcomes were generally measured between eight to 32 weeks (mean 19.7 weeks) of therapy.Assessed comparisons included oral isotretinoin versus placebo or other treatments such as antibiotics. In addition, different doses, regimens, or formulations of oral isotretinoin were assessed, as well as oral isotretinoin with the addition of topical agents.Pharmaceutical companies funded 12 included trials. All, except three studies, had high risk of bias in at least one domain.Oral isotretinoin compared with oral antibiotics plus topical agentsThese studies included participants with moderate or severe acne and assessed outcomes immediately after 20 to 24 weeks of treatment (short-term). Three studies (400 participants) showed isotretinoin makes no difference in terms of decreasing trial investigator-assessed inflammatory lesion count (RR 1.01 95% CI 0.96 to 1.06), with only one serious adverse effect found, which was Stevens-Johnson syndrome in the isotretinoin group (RR 3.00, 95% CI 0.12 to 72.98). However, we are uncertain about these results as they were based on very low-quality evidence.Isotretinoin may slightly improve (by 15%) acne severity, assessed by physician's global evaluation (RR 1.15, 95% CI 1.00 to 1.32; 351 participants; 2 studies), but resulted in more less serious adverse effects (67% higher risk) (RR 1.67, 95% CI 1.42 to 1.98; 351 participants; 2 studies), such as dry lips/skin, cheilitis, vomiting, nausea (both outcomes, low-quality evidence).Different doses/therapeutic regimens of oral isotretinoinFor our primary efficacy outcome, we found three RCTs, but heterogeneity precluded meta-analysis. One study (154 participants) reported 79%, 80% and 84% decrease in total inflammatory lesion count after 20 weeks of 0.05, 0.1, or 0.2 mg/kg/d of oral isotretinoin for severe acne (low-quality evidence). Another trial (150 participants, severe acne) compared 0.1, 0.5, and 1 mg/kg/d oral isotretinoin for 20 weeks and, respectively, 58%, 80% and 90% of participants achieved 95% decrease in total inflammatory lesion count. One RCT, of participants with moderate acne, compared isotretinoin for 24 weeks at (a) continuous low dose (0.25 to 0.4 mg/kg/day), (b) continuous conventional dose (0.5 to 0.7 mg/kg/day), and (c) intermittent regimen (0.5 to 0.7 mg/kg/day, for one week in a month). Continuous low dose (MD 3.72 lesions; 95% CI 2.13 to 5.31; 40 participants; one study) and conventional dose (MD 3.87 lesions; 95% CI 2.31 to 5.43; 40 participants; one study) had a greater decrease in inflammatory lesion counts compared to intermittent treatment (all outcomes, low-quality evidence).Fourteen RCTs (906 participants, severe and moderate acne) reported that no serious adverse events were observed when comparing different doses/therapeutic regimens of oral isotretinoin during treatment (from 12 to 32 weeks) or follow-up after end of treatment (up to 48 weeks). Thirteen RCTs (858 participants) analysed frequency of less serious adverse effects, which included skin dryness, hair loss, and itching, but heterogeneity regarding the assessment of the outcome precluded data pooling; hence, there is uncertainty about the results (low- to very-low quality evidence, where assessed).Improvement in acne severity, assessed by physician's global evaluation, was not measured for this comparison.None of the included RCTs reported birth defects.

AUTHORS' CONCLUSIONS

Evidence was low-quality for most assessed outcomes.We are unsure if isotretinoin improves acne severity compared with standard oral antibiotic and topical treatment when assessed by a decrease in total inflammatory lesion count, but it may slightly improve physician-assessed acne severity. Only one serious adverse event was reported in the isotretinoin group, which means we are uncertain of the risk of serious adverse effects; however, isotretinoin may result in more minor adverse effects.Heterogeneity in the studies comparing different regimens, doses, or formulations of oral isotretinoin meant we were unable to undertake meta-analysis. Daily treatment may be more effective than treatment for one week each month. None of the studies in this comparison reported serious adverse effects, or measured improvement in acne severity assessed by physician's global evaluation. We are uncertain if there is a difference in number of minor adverse effects, such as skin dryness, between doses/regimens.Evidence quality was lessened due to imprecision and attrition bias. Further studies should ensure clearly reported long- and short-term standardised assessment of improvement in total inflammatory lesion counts, participant-reported outcomes, and full safety accounts. Oral isotretinoin for acne that has not responded to oral antibiotics plus topical agents needs further assessment, as well as different dose/regimens of oral isotretinoin in acne of all severities.

Akne

Akne ist eine chronische Erkrankung mit hoher Prävalenz unter Jugendlichen. Pathogenetische Hauptfaktoren (und ihre klinischen Korrelate) sind gesteigerte Talgproduktion (Seborrhoe), follikuläre Hyperkeratose (Komedonen) und perifollikuläre Entzündungsvorgänge (Papulopusteln). Die Krankheit wird von endogenen (Androgene, IGF-1, neuroendokrine Faktoren) und exogenen (Propionibacterium acnes, Diät, mechanische Irritation, Inhaltsstoffe medizinischer oder kosmetischer Externa) Einflüssen moduliert. Akne geht mit zum Teil hoher Morbidität einher und kann bereits bei leichter Ausprägung eine erhebliche Verschlechterung der Lebensqualität bewirken. Zu Therapie stehen wirksame topische und systemische Behandlungsverfahren zur Verfügung. Eine optimale Behandlung erfordert eine stadiengerechtes Management und kontinuierliche ärztliche Begleitung der Patienten über den erforderlichen Behandlungszeitraum.

Chemical peels in the treatment of acne: patient selection and perspectives

Acne vulgaris is the most common skin disorder in adolescents and young adults. It carries a significant psychological and economic burden to patients and society. A wide range of therapeutic options are available, including topicals and systemic therapies. Chemical peeling is a skin resurfacing procedure intended to regenerate normal skin from the application of exfoliative agents. It has been used for the treatment of acne vulgaris and other skin disorders for decades. There are several chemical agents with variable mechanisms of action, usually classified as superficial, medium, and deep peels. When selecting the patient and the appropriate peel, the dermatologist individualizes therapy, and performs an extensive interview, including past medical history and physical exam. Several host factors can affect the outcome of this procedure, including current psychological state, medications, history of surgery, and immune system, among others. The physician must also be confident that the peel is safe and effective for the target patient. The Fitzpatrick skin type scale is a useful tool to classify patients based on skin color and ability to tan, but also can be used to evaluate preoperative risk of postpeel response and complications. Dark-skinned patients (Fitzpatrick skin type IV-VI), including blacks, Asian, and Hispanic/Latino, are at higher risk of postinflammatory/postpeel hyperpigmentation. When treating these populations, deep chemical peels should be avoided, and preoperative preparation emphasized. There are many studies available in the literature supporting the use of superficial to medium depth peels as adjuvant therapy for acne vulgaris. This review article aims to present the most important factors when selecting a patient for a chemical peel, the evidence behind its safety and efficacy, and special considerations when choosing a specific agent.

Adult-onset acne: prevalence, impact, and management challenges

Acne is a multifactorial and inflammatory disease of pilosebaceous follicles, which affects most adolescents. Recent epidemiological data revealed a difference in adults affected by this disease. Women have a high prevalence and incidence when compared with men, especially after 25 years of age. In contrast to what was initially thought, most of these patients do not present endocrinopathy capable of leading to the development of the lesions. When present, polycystic ovarian syndrome is the main cause. However, in these cases, acne is rarely the only dermatological manifestation; hirsutism and acanthosis nigricans are often present. The majority of the normoandrogenic acne patients present a history since adolescence, but in many cases the lesion distribution and intensity change with time. There is often a typical localization of the lesions in the lower third of the face and lateral region of the neck. Another interesting feature is related to the impact on quality of life (QoL), which is always intense. Often there are signs of depression, even when the lesions are mild. As most adult patients are women, in addition to the conventional options, there is also hormone treatment. Combined oral contraceptives and spironolactone are good options. Knowing more about the particularities in etiopathogenesis, impact on QoL, and specific treatment options is important to all dermatologists who face the challenge of treating acne in adults.

Genetic architecture of acne vulgaris

Acne vulgaris is a ubiquitary skin disease characterized by chronic inflammation of the pilosebaceous unit resulting from bacterial colonization of hair follicles by Propionibacterium acnes, androgen-induced increased sebum production, altered keratinization and inflammation. Here, we review our current understanding of the genetic architecture of this intriguing disease. We analysed genomewide association studies (GWAS) and candidate genes studies for acne vulgaris. Moreover, we included GWAS studies for the associated disease polycystic ovary syndrome (PCOS). Overall, the available data revealed sixteen genetic loci flagged by single nucleotide polymorphisms (SNPs), none of which has been confirmed yet by independent studies. Moreover, a GWAS for PCOS identified 21 susceptible loci. The genetic architecture is complex which has been revealed by GWAS. Further and larger studies in different populations are required to confirm or disprove results from candidate gene studies as well to identify signals that may overlap between different populations. Finally, studies on rare genetic variants in acne and associated diseases like PCOS may deepen our understanding of its pathogenesis.

Cell type-specific regulatory effects of glucocorticoids on cutaneous TLR2 expression and signalling

Glucocorticoids (GCs) induce Toll-like receptor (TLR) 2 expression and synergistically upregulate TLR2 with pro-inflammatory cytokines or bacteria. These paradoxical effects have drawn attention to the inflammatory initiating or promoting effects of GCs, as GC treatment can provoke inflammatory skin diseases. Here, we aimed to investigate the regulatory effects of GCs in human skin cells of different epidermal and dermal layers. We found that Dex induced TLR2 expression mainly in undifferentiated and less in calcium-induced differentiated keratinocytes but not in HaCaT cells or fibroblasts, however, Dex reduced TLR1/6 expression. Stimulation with Dex under inflammatory conditions further increased TLR2 but not TLR1 or TLR6 levels in keratinocytes. Increased ligand-induced interaction of TLR2 with MyD88 and expression of the adaptor protein TRAF6 indicated enhanced TLR2 signalling, whereas TLR2/1 or TLR2/6 signalling was not increased in Dex-pretreated keratinocytes. GC-increased TLR2 expression was negatively regulated by JNK MAPK signalling when stimulated with Propionibacterium acnes. Our results provide novel insights into the molecular mechanisms of glucocorticoid-mediated expression and function of TLR2 in human skin cells and the understanding of the mechanisms of corticosteroid side effects.

Clinical comparison of salicylic acid peel and LED-Laser phototherapy for the treatment of Acne vulgaris in teenagers

Acne vulgaris treatments usually cause sensitivity, teratogenicity and bacterial resistance. Investigations of other therapeutic techniques, such as phototherapy, are highly relevant. Thus, we compared the effectiveness of two Acne vulgaris treatments in adolescents: peeling with salicylic acid (SA) and phototherapy. Teens were randomly divided into: group I, treatment with SA peels (10%) and group II, treatment with phototherapy (blue LED and red laser lights). Photographs were taken before and after ten sessions of each treatment, carried out weekly, and compared. To compare the differences between the treatments, the Student t-test was used. P values < 0.05 were considered significant. Both techniques are effective therapies for the treatment of acne in teenagers since the number of comedones, papules and pustules decreased significantly at the end of the session. However, when the two treatments were compared, phototherapy showed a significant difference in reducing the number of pustules. The combined use of red and blue lights due to their anti-inflammatory and wound-healing properties is a more efficient alternative for treating Acne vulgaris in relation to SA and proves more reliable and without side effects, improving the adolescents' skin health.

Jessner's solution vs. 30% salicylic acid peels: a comparative study of the efficacy and safety in mild-to-moderate acne vulgaris

INTRODUCTION

Chemical peeling is a well-identified therapeutic modality for acne vulgaris (AV). Jessner's solution (JS) is a known peeling agent for acne since more than 100 years. Salicylic acid (SA) peel is a well-established peeling agent for acne. There is paucity of literature comparing the current peeling agents of choice, that is, SA with the older peeling agents, that is, JS for acne.

OBJECTIVE

To compare the efficacy and safety of 30% SA vs. JS peels in treatment of mild-to-moderate facial acne in Indian patients.

MATERIALS AND METHOD

A total of 40 patients with mild-to-moderate AV were enrolled for 12 weeks and were randomly divided into two groups: group 1, 30% SA peels and group 2, JS peels were performed 2 weeks apart with total of six peels in 12-week duration. Clinical improvement was assessed objectively using Michaelsson acne scores (MAS) and clinical photographs. Side effects were observed at each visit.

RESULTS

At the end of therapy, improvement in MAS and percentage decrease in MAS were significantly higher in group 1 as compared to group 2. Likewise, decrease in mean comedone counts in group 1 was significantly higher as compared to group 2. However, there was no statistically significant difference in the decrease in mean papule and pustule counts between the two groups. Both the groups tolerated the peels well.

CONCLUSION

Thus, 30% SA peels were more effective than JS peels in treatment of noninflammatory lesions, that is, comedones and in overall improvement of mild-to-moderate facial acne vulgaris.

Treatment Modalities for Acne

Acne is a common inflammatory skin disease which affects the pilosebaceous units of the skin. It can have severe psychological effects and can leave the patient with severe skin scarring. There are four well-recognized pathological factors responsible for acne which is also the target for acne therapy. In this review, different treatment options are discussed, including topical (i.e., retinoids, and antibiotics) and systemic (i.e., retinoids, antibiotics, and hormonal) treatments. Since the general public has been showing an increasing interest in more natural and generally safer treatment options, the use of complementary and alternative medicines (CAM) for treating acne was also discussed. The use of physical therapies such as comedone extraction, cryoslush therapy, cryotherapy, electrocauterization, intralesional corticosteroids and optical treatments are also mentioned. Acne has been extensively researched with regards to the disease mechanism as well as treatment options. However, due to the increasing resistance of Propionibacterium acnes towards the available antibiotics, there is a need for new treatment methods. Additionally, the lack of necessary evidence on the efficacy of CAM therapies makes it necessary for researchers to investigate these treatment options further.

Treatment of Inflammatory Acne with a Combination Therapy with Lymecycline and Adapalene Followed by Maintenance Treatment with Adapalene

Oral antibiotics, especially tetracyclines, are commonly used to treat moderate to moderately severe acne vulgaris. There are hints suggesting that a combination treatment with oral tetracyclines and topical retinoids can cause a greater and prompter improvement of acne than monotherapy with tetracyclines. We evaluated the clinical activity of a 12-week combined therapy with oral lymecycline (300mg/day for 2 weeks and then 150mg/day) and topical adapalene (gel or cream) in 419 patients with inflammatory acne. A significant reduction in the number of acne lesions was noted at 4 and 12 weeks (P<0.0001). Thereafter, 400 patients underwent a maintenance treatment with adapalene alone for 12 weeks. At week 24 a relevant improvement of acne lesions still persisted (P<0.0001) in most patients. Only 16 patients relapsed and required additional use of oral lymecycline which proved again successful. No substantial differences were noted in the magnitude of clinical response between patients treated with adapalene gel and those treated with cream formulation. Treatment was well tolerated. Local adverse reactions occurred in 11.7 % of patients and resulted in premature discontinuation of treatment in 1.4 %. Systemic (gastrointestinal) untoward effects developed in 1.2 % of patients and caused treatment interruption in 0.7 % of cases. No serious adverse events occurred.

Vitamin B12 modulates the transcriptome of the skin microbiota in acne pathogenesis

Various diseases have been linked to the human microbiota, but the underlying molecular mechanisms of the microbiota in disease pathogenesis are often poorly understood. Using acne as a disease model, we aimed to understand the molecular response of the skin microbiota to host metabolite signaling in disease pathogenesis. Metatranscriptomic analysis revealed that the transcriptional profiles of the skin microbiota separated acne patients from healthy individuals. The vitamin B12 biosynthesis pathway in the skin bacterium Propionibacterium acnes was significantly down-regulated in acne patients. We hypothesized that host vitamin B12 modulates the activities of the skin microbiota and contributes to acne pathogenesis. To test this hypothesis, we analyzed the skin microbiota in healthy subjects supplemented with vitamin B12. We found that the supplementation repressed the expression of vitamin B12 biosynthesis genes in P. acnes and altered the transcriptome of the skin microbiota. One of the 10 subjects studied developed acne 1 week after vitamin B12 supplementation. To further understand the molecular mechanism, we revealed that vitamin B12 supplementation in P. acnes cultures promoted the production of porphyrins, which have been shown to induce inflammation in acne. Our findings suggest a new bacterial pathogenesis pathway in acne and provide one molecular explanation for the long-standing clinical observation that vitamin B12 supplementation leads to acne development in a subset of individuals. Our study discovered that vitamin B12, an essential nutrient in humans, modulates the transcriptional activities of skin bacteria, and provided evidence that metabolite-mediated interactions between the host and the skin microbiota play essential roles in disease development.

Staphylococcal LTA-Induced miR-143 Inhibits Propionibacterium acnes-Mediated Inflammatory Response in Skin

Staphylococcus epidermidis (S. epidermidis) plays a critical role in modulating cutaneous inflammatory responses in skin. Although S. epidermidis has been shown to co-colonize with Propionibacterium acnes (P. acnes) in acne lesions, it is unclear whether S. epidermidis is involved in the regulation of P. acnes-induced inflammatory responses. In this study, we demonstrated that S. epidermidis inhibited P. acnes-induced inflammation in skin. P. acnes induced the expression of interleukin-6 and tumor necrosis factor-α via the activation of toll-like receptor (TLR) 2 in both keratinocytes and mouse ears. Staphylococcal lipoteichoic acid activated TLR2 to induce miR-143 in keratinocytes, and miR-143, in turn, directly targeted 3' UTR of TLR2 to decrease the stability of TLR2 mRNA and then decreased TLR2 protein, thus inhibiting P. acnes-induced proinflammatory cytokines. The inhibitory effect of miR-143 was further confirmed in vivo as the administration of miR-143 antagomir into mouse ears abrogated the inhibitory effect of lipoteichoic acid on P. acnes-induced inflammation in skin. Taken together, these observations demonstrate that staphylococcal lipoteichoic acid inhibits P. acnes-induced inflammation via the induction of miR-143, and suggest that local modulation of inflammatory responses by S. epidermidis at the site of acne vulgaris might be a beneficial therapeutic strategy for management of P. acnes-induced inflammation.

Photodynamic therapy with methyl aminolaevulinate 80 mg g(-1) for severe facial acne vulgaris: a randomized vehicle-controlled study

BACKGROUND

Severe acne vulgaris has limited therapeutic options.

OBJECTIVES

To evaluate photodynamic therapy (PDT) using topical methyl aminolaevulinate (MAL, 80 mg g(-1) ) as the photosensitizer in severe facial acne.

METHODS

A double-blind, randomized, vehicle-controlled multicentre trial in 153 patients (aged 12-35 years) with severe facial acne [Investigator's Global Assessment (IGA) score 4; 25-75 inflammatory lesions with ≤ 3 nodules; 20-100 noninflammatory lesions]. Treatment (four treatments 2 weeks apart) involved incubation with MAL (n = 100) or vehicle cream (n = 53) for 1·5 h under occlusion, then illumination (635-nm red light, total dose 37 J cm(-2) ). IGA assessment and standardized lesion counts were performed before each treatment and 12 weeks after the first treatment. Treatment success was defined as improvement from baseline in IGA by ≥ 2 grades at 12 weeks. Safety assessments were for pain (10-cm visual analogue scale, immediately after illumination), erythema (four-point rating scale) and adverse events.

RESULTS

At 12 weeks, PDT using MAL 80 mg g(-1) reduced inflammatory lesions vs. vehicle PDT (mean change -15·6 vs. -7·8, P = 0·006; mean percentage change -37·3% vs. -16·2%, P = 0·003). However, noninflammatory lesions did not decrease significantly (mean change -11·8 vs. -10·7, P = 0·85; mean percentage change -28·6% vs. -24·9%, P = 0·72). Treatment success rates were greater with MAL-PDT 80 mg g(-1) (44% vs. 26%, P = 0·013). Pain was low and manageable by briefly pausing illumination. There was similar pain or erythema with successive treatments.

CONCLUSIONS

PDT using topical MAL 80 mg g(-1) and red light may offer promise for severe acne vulgaris.

Self-assembled polymeric nanocarriers for the targeted delivery of retinoic acid to the hair follicle

Acne vulgaris is a highly prevalent dermatological disease of the pilosebaceous unit (PSU). An inability to target drug delivery to the PSU results in poor treatment efficacy and the incidence of local side-effects. Cutaneous application of nanoparticulate systems is reported to induce preferential accumulation in appendageal structures. The aim of this work was to prepare stable polymeric micelles containing retinoic acid (RA) using a biodegradable and biocompatible diblock methoxy-poly(ethylene glycol)-poly(hexylsubstituted lactic acid) copolymer (MPEG-dihexPLA) and to evaluate their ability to deliver RA to skin. An innovative punch biopsy sample preparation method was developed to selectively quantify follicular delivery; the amounts of RA present were compared to those in bulk skin, (i.e. without PSU), which served as the control. RA was successfully incorporated into micelle nanocarriers and protected from photoisomerization by inclusion of Quinoline Yellow. Incorporation into the spherical, homogeneous and nanometer-scale micelles (dn < 20 nm) increased the aqueous solubility of RA by >400-fold. Drug delivery experiments in vitro showed that micelles were able to deliver RA to porcine and human skins more efficiently than Retin-A(®) Micro (0.04%), a marketed gel containing RA loaded microspheres, (7.1 ± 1.1% vs. 0.4 ± 0.1% and 7.5 ± 0.8% vs. 0.8 ± 0.1% of the applied dose, respectively). In contrast to a non-colloidal RA solution, Effederm(®) (0.05%), both the RA loaded MPEG-dihexPLA polymeric micelles (0.005%) and Retin-A(®) Micro (0.04%) displayed selectivity for delivery to the PSU with 2-fold higher delivery to PSU containing samples than to control samples. Moreover, the micelle formulation outperformed Retin-A(®) Micro in terms of delivery efficiency to PSU presenting human skin (10.4 ± 3.2% vs. 0.6 ± 0.2%, respectively). The results indicate that the polymeric micelle formulation enabled an increased and targeted delivery of RA to the PSU, potentially translating to a safer and more efficient clinical management of acne.