Optimal treatments and outcome measures of palmoplantar pustulosis: A systematic review and network meta-analysis-based comparison of treatment efficacy

Few studies have made direct comparisons between treatments for palmoplantar pustulosis (PPP); therefore, it is difficult to select the best treatment for each patient. To determine the best therapy and to compare reported measures of efficacy in clinical trials of systemic treatments for PPP in this systematic review and network meta-analysis. Six databases were used to perform database search on 10 July 2022. Randomized controlled trials (RCTs) were identified through a systematic literature search. The titles and abstracts of articles were initially screened for inclusion by two authors independently using our predetermined criteria. The full texts of selected articles were then independently assessed for inclusion in a blinded fashion. Disagreement between the authors was resolved by consensus. Data were abstracted in duplicate. Random-effects model was accepted to perform network meta-analysis. Assessed Grading of Recommendations Assessment, Development and Evaluation certainty of evidence were performed according to the PRISMA guidelines. The analysis was completed in July 2022. The primary outcome was the change of PPP Area and Severity Index (PPPASI) from baseline and the secondary outcome was the achievement of PPPASI-50 response. Seven RCTs with 567 patients were included. Guselkumab 100 mg was the one with the highest probability of reaching the proposed outcomes (mean difference [MD], -8.00; 95% confidence interval [CI], 4.88-11.11), while the achievement of PPPASI-50 response did not show a significant difference (odds ratio [OR], 3.79; 95% CI, 0.51-28.37). Guselkumab 200 mg was next to 100 mg of reaching the proposed outcomes (MD, -4.71; 95% CI, 2.12-7.30), while the achievement of PPPASI-50 response did not show a significant difference (OR, 2.34; 95% CI, 0.48-11.43). Network meta-analysis showed guselkumab 100 mg was the treatment with the highest probability of reaching both PPPASI and PPPASI-50 outcomes. Absolute PPPASI may be more appropriate as an outcome than PPPASI-50.

The role of aryl hydrocarbon receptor in vitiligo: a review

Vitiligo is an acquired autoimmune dermatosis characterized by patchy skin depigmentation, causing significant psychological distress to the patients. Genetic susceptibility, environmental triggers, oxidative stress, and autoimmunity contribute to melanocyte destruction in vitiligo. Due to the diversity and complexity of pathogenesis, the combination of inhibiting melanocyte destruction and stimulating melanogenesis gives the best results in treating vitiligo. The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that can regulate the expression of various downstream genes and play roles in cell differentiation, immune response, and physiological homeostasis maintenance. Recent studies suggested that AhR signaling pathway was downregulated in vitiligo. Activation of AhR pathway helps to activate antioxidant pathways, inhibit abnormal immunity response, and upregulate the melanogenesis gene, thereby protecting melanocytes from oxidative stress damage, controlling disease progression, and promoting lesion repigmentation. Here, we review the relevant literature and summarize the possible roles of the AhR signaling pathway in vitiligo pathogenesis and treatment, to further understand the links between the AhR and vitiligo, and provide new potential therapeutic strategies.

The effect of the ketogenic diet on Acne: Could it be a therapeutic tool?

Acne is a chronic inflammatory disease of the pilosebaceous unit resulting from androgen-induced increased sebum production, altered keratinization, inflammation, and bacterial colonization of the hair follicles of the face, neck, chest and back by Propionibacterium acnes. Overall, inflammation and immune responses are strongly implicated in the pathogenesis of acne. Although early colonization with Propionibacterium acnes and family history may play an important role in the disease, it remains unclear exactly what triggers acne and how treatment affects disease progression. The influence of diet on acne disease is a growing research topic, yet few studies have examined the effects of diet on the development and clinical severity of acne disease, and the results have often been contradictory. Interestingly, very low-calorie ketogenic diet (VLCKD) has been associated with both significant reductions in body weight and inflammatory status through the production of ketone bodies and thus it has been expected to reduce the exacerbation of clinical manifestations or even block the trigger of acne disease. Given the paucity of studies regarding the implementation of VLCKD in the management of acne, this review aims to provide evidence from the available scientific literature to support the speculative use of VLCKD in the treatment of acne.

Role of Aryl Hydrocarbon Receptor Activation in Inflammatory Chronic Skin Diseases

Aryl Hydrocarbon Receptor (AhR) is an evolutionary transcription factor which acts as a crucial sensor of different exogenous and endogenous molecules Recent data indicate that AhR is implicated in several physiological processes such as cell physiology, host defense, proliferation and differentiation of immune cells, and detoxification. Moreover, AhR involvement has been reported in the development and maintenance of several pathological conditions. In recent years, an increasing number of studies have accumulated highlighting the regulatory role of AhR in the physiology of the skin. However, there is evidence of both beneficial and harmful effects of AHR signaling. At present, most of the evidence concerns inflammatory skin diseases, in particular atopic dermatitis, psoriasis, acne, and hidradenitis suppurativa. This review exam-ines the role of AhR in skin homeostasis and the therapeutic implication of its pharmacological modulation in these cutaneous inflammatory diseases.

Environmental, inflammatory, and anti-inflammatory squad in acne vulgaris pathogenesis: AhR, IL-36, and IL-38

BACKGROUND

Acne vulgaris (AV) is an extraordinarily common skin condition. The high prevalence of AV is linked to the exposure factors, as environmental pollutants and climatic factors, occupational, psychosocial, and lifestyle factors. The AhR plays a critical part in environmental toxic action. The AhR expression and imbalance in the IL-36 & 38 expression may have a role in inflammation and AV pathogenesis.

AIMS

To detect possible links between environmental, inflammatory, and anti-inflammatory factors in AV pathogenesis through measuring AhR, IL-36, and IL-38 mRNA gene expression levels.

PATIENTS AND METHODS

Total of 100 subjects (70 AV patients and 30 apparently healthy control subjects) were tested for AhR, IL-36γ, and IL-38 mRNA levels by quantitative real-time PCR.

RESULTS

The median levels of AhR and IL-36 mRNA gene expression were considerably greater, while that of IL-38 was essentially lower in AV than healthy subjects (p < 0.001, 0.021 and 0.002, respectively). The AhR and IL-36 mRNA gene expression levels increased, while IL-38 decreased significantly with higher grades of severity (p < 0.001, 0.001, and <0.001, respectively). ROC curve showed that AhR mRNA gene expression level had the best AUC for diagnosis of AV, with better sensitivity and specificity than IL-36 and IL-38.

CONCLUSIONS

Higher levels of AhR, IL-36, and lower levels of IL-38 gene expression were significantly associated with AV patients and higher grades of severity. AhR had better diagnostic ability than IL-38 and IL-36.

Cutibacterium acnes: Much ado about maybe nothing much

Cutibacterium acnes (also known as Propionibacterium acnes) has long been implicated in the pathogenesis of acne, inspiring both therapeutic and personal care approaches aiming to control the disease by controlling the bacterium. The purported association has made people with acne feel dirty and led to the-at times excessive-use of cleansers, antiseptics and antibiotics for the condition. However, recent evidence seems to weaken the case for C. acnes' involvement. New genetics and molecular biology findings strongly suggest that abnormal differentiation of sebaceous progenitor cells causes comedones, the primary lesions in acne. Comodegenesis is initiated by androgens and is unlikely to be triggered by C. acnes, which probably doesn't affect sebaceous differentiation. Is there still a place for it in this understanding of acne? It is necessary to critically address this question because it has consequences for treatment. Antibiotic use for acne noticeably contributes to microbial drug resistance, which we can ill afford. In this Viewpoint, we explore if and how C. acnes (still) fits into the developing view on acne. We also briefly discuss the implications for therapy in the light of antibiotic resistance and the need for more targeted therapies.

Chloracne: a case series on cutaneous expression of CYP1A1 as diagnostic biomarker

Chloracne, also known as metabolizing acquired dioxin-induced skin hamartomas (MADISH), is a rare disfiguring disease related to dioxin exposure. There is a paucity of literature on the clinical manifestations and pathogenesis of chloracne/MADISH. The aim of this study was to assess the clinical features of this very unusual acneiform eruption and to explore the pathogenesis of the disease. This was a retrospective, observational report study was conducted on five patients belonging to the same nuclear family (father, mother and three children) and a relative (father's brother) living in the same house. Histopathological, immunohistochemical, laboratory and toxicological analyses were performed for all patients. The results suggest that CYP1A1 in human skin is a diagnostic biomarker in chloracne, and was positive for all the patients in our sample. Tetrachlorodibenzo-p-dioxin is the most investigated dioxin responsible for chloracne; however, several other agonists, whether dioxin-like or not, can activate the aryl hydrocarbon receptor. To our knowledge, this Italian case series is the first study to suggest polychlorinated biphenyls as a possible cause of an overstimulation of aryl hydrocarbons causing the consequent acneiform eruption.

Inhibition and induction of CYP enzymes in humans: an update

The cytochrome P450 (CYP) enzyme family is the most important enzyme system catalyzing the phase 1 metabolism of pharmaceuticals and other xenobiotics such as herbal remedies and toxic compounds in the environment. The inhibition and induction of CYPs are major mechanisms causing pharmacokinetic drug–drug interactions. This review presents a comprehensive update on the inhibitors and inducers of the specific CYP enzymes in humans. The focus is on the more recent human in vitro and in vivo findings since the publication of our previous review on this topic in 2008. In addition to the general presentation of inhibitory drugs and inducers of human CYP enzymes by drugs, herbal remedies, and toxic compounds, an in-depth view on tyrosine-kinase inhibitors and antiretroviral HIV medications as victims and perpetrators of drug–drug interactions is provided as examples of the current trends in the field. Also, a concise overview of the mechanisms of CYP induction is presented to aid the understanding of the induction phenomena.

Symurban Nanocrystals for Advanced Anti-Pollution Skincare

Several of most common dermatoses worldwide, e.g., psoriasis and atopic dermatitis, are worsened in their clinical picture when the skin is regularly exposed to an increased air pollution level, e.g., particulate matter. This is explainable by the activation of the aryl hydrocarbon receptor (AhR) in the skin, which results in an increased release of proinflammatory cytokines and matrix metalloproteinases. Symurban is a competitive AhR antagonist and thus allows the effective protection of skin. In order to improve its dermal bioavailability as a poorly soluble active agent (0.25 µg/mL), nanocrystals were prepared and evaluated. Nanocrystals are pure active crystals reduced in particle size to the submicron range of 100 to 1000 nm. They feature the properties of nanocrystals, such as increased saturation solubility and dissolution velocity, without having to be declared as nanomaterial. Production methods and parameters were systematically investigated. Wet bead milling at 2000 rpm for 30 min yielded the best results. A z-average of 280 nm was achieved for a 10% Symurban suspension with a polydispersity index of 0.20, indicating a narrow size distribution. For the long-term stabilization of the nanocrystal suspension, the performance of 15 surfactants of different categories and HLB values were investigated and evaluated. It was found that non-ionic surfactants in general were better able to stabilize the system than anionic or amphoteric surfactants. Highest stability of over 12 months at 25 °C was achieved with 2% Plantacare 810 UP, an ECOCERT surfactant with high skin tolerance. The suspension was also chemically long-term stable with >97% of remaining Symurban over 12 months. The saturation solubility of Symurban as nanocrystals was significantly increased from 0.25 to 2.9 μg/mL, which corresponds to a factor of >11. In a case study of one male volunteer with healthy skin conditions, penetration profiles of Symurban nanocrystal hydrogel and commercial anti-pollution serum containing an identical amount of Symurban were determined and compared. After 20 min of exposure, the relative Symurban concentration in the deeper skin layers (tape 19-30) was more than two times higher for nanocrystal hydrogel (16%) than the commercial serum (7%). These results suggest that nanocrystals are a promising delivery system for the poorly soluble anti-pollution agent Symurban.

Expression of CYP1A1, CYP1B1 and IL-1β in PBMCs and skin samples of PCB exposed individuals

Polychlorinated biphenyls (PCBs) are well- known man-made persistent environmental pollutants and endocrine disruptors. As a result of mass production in the past, background levels of these compounds can be measured in human blood worldwide. In 2010 high internal levels of PCBs were discovered in workers of a transformer-recycling company in Germany. Our aim was to measure, whether the expression of CYP1A1, CYP1B1, and IL-1β is dysregulated in peripheral blood mononuclear cells (PBMCs) of the exposed individuals (n = max 308). Further, we measured the regulation of CYP1A1, CYP1B1, AHRR (aromatic hydrocarbon receptor repressor) and IL-1β in skin samples of 25 workers with elevated plasma PCB levels using quantitative PCR (q-RT-PCR). We found a significant correlation between the regulation of IL-1β in skin samples and lipid adjusted PCB levels. In the PBMCs, the expression levels of CYP1A1, CYP1B1 and IL-1β decreased over time with decreasing PCB plasma levels. The upregulation of the cytokine IL-1β in exposed individuals with higher PCB plasma levels warrants further investigation in order to examine its role in the pathophysiology of autoimmune disorders and tumor promotion.

Cutaneous Adnexal Cysts Revisited: What We Know and What We Think We Know

Cutaneous cysts have been classified by dermatopathologists in many different ways. Here, we propose a novel classification of cutaneous adnexal cysts according to their origin in the folliculosebaceous unit and the sweat glands. By examining the lining of the cystic structure, its origin can be easily identified. Epidermal cysts have an epithelial wall containing a granular layer with lamellar keratinization, indicating an infundibular origin. Tricholemmal cysts have an undulating epithelial wall with no granular layer and a compact keratinization, showing an isthmic origin. In steatocystoma, dermoid cyst, and folliculosebaceous hamartoma, the epithelial lining shows a crenulated appearance which is seen in the sebaceous duct. Hidrocystoma shows the characteristic cuboidal epithelial lining of sweat glands with decapitation secretion in its apocrine forms. The hair matrix cyst wall is composed of basaloid cells maturing to squamoid cells, as seen in the normal hair matrix and shadow cells in the lumen. Metabolizing acquired dioxin-induced skin hamartoma (MADISH) is a cystic lesion with lamellar keratinization, and no sebaceous glands. The classification proposed here aims to simplify the complexity of cutaneous adnexal cysts, and to facilitate a better understanding of the origin of cystic lesions of the skin.

Aryl hydrocarbon receptor (AhR) a possible target for the treatment of skin disease

Aryl hydrocarbon receptor (AhR) is a transcription factor expressed in all skin cells type. It responds to exogenous and endogenous chemicals by inducing/repressing the expression of several genes with toxic or protective effects in a wide range of species and tissues. In healthy skin, AhR signalling contributes to keratinocytes differentiation, skin barrier function, skin pigmentation, and mediates oxidative stress. In the last years, some studies have shown that AhR seems to be involved in the pathogenesis of some skin diseases, even if the currently available data are contradictory. Indeed, while the blocking the AhR signalling activity could prevent or treat skin cancer, the AhR activation seems to be advantageous for the treatment of inflammatory skin diseases. Therefore, for its multifaceted role in skin diseases, AhR seems to be an attractive therapeutic target. Indeed, recently some molecules have been identified for the prevention of skin cancer and the treatment of inflammatory skin diseases.

The influence of exposome on acne

BACKGROUND

Acne vulgaris is one of the main reasons for dermatological consultations. Severity and response to treatment may be impacted by various external factors or exposome.

AIM

To assess the impact of environmental factors on acne and to provide a comprehensive overview of the acne exposome.

METHODS

Two consensus meetings of five European dermatologists and a comprehensive literature search on exposome factors triggering acne served as a basis for this review.

RESULTS

Acne exposome was defined as the sum of all environmental factors influencing the occurrence, duration and severity of acne. Exposome factors impact on the response and the frequency of relapse to treatments by interacting with the skin barrier, sebaceous gland, innate immunity and cutaneous microbiota. They may be classified into the following six main categories: nutrition, psychological and lifestyle factors, occupational factors including cosmetics, as well as pollutants, medication and climatic factors. Moreover, practical considerations for the dermatologist's clinical practice are proposed.

CONCLUSION

Exposome factors including nutrition, medication, occupational factors, pollutants, climatic factors, and psychosocial and lifestyle factors may impact on the course and severity of acne and on treatment efficacy. Identifying and reducing the impact of exposome is important for an adequate acne disease management.