Neurovascular and neuroimmune aspects in the pathophysiology of rosacea

Rosacea in Older Adults and Pharmacologic Treatments

Rosacea is a chronic inflammatory skin condition that is often more severe in older patients. The main clinical features are erythema, telangiectasia, and inflammatory lesions of the face. The pathogenesis of this condition is not fully understood but certainly multifaceted. Immune and inflammatory dysregulation, genetics, neurogenic dysregulation, microbiome dysbiosis, and systemic disease have all been implicated in rosacea pathogenesis. As we better understand the various pathways that lead to rosacea, we acknowledge that the different symptoms may have unique underlying triggers and mechanisms. Aging also impacts rosacea diagnosis and treatment. Older adults have more severe rosacea symptoms while also having more sensitive and fragile skin than younger patients; therefore, rosacea treatments for older patients require a balance between delivering adequate potency while also minimizing skin irritation and other adverse effects. Until recently, rosacea diagnoses were based on concrete subtypes that did not necessarily capture each patient's manifestation of rosacea. There is now an emphasis on more personalized phenotype-based diagnoses and treatments, which allows for more emphasis on treating individual symptoms and accounting for the unique characteristics of older patients. Centrofacial erythema is best treated with brimonidine and oxymetazoline, while phymatous change and telangiectasia are best treated with surgery and laser ablation. Treatment for rosacea papules and pustules ranges from topicals, such as azelaic acid, ivermectin, metronidazole, minocycline, and encapsulated benzoyl peroxide, to systemics, such as doxycycline and isotretinoin. It is important to understand these treatments in relation to adverse effects and drug interactions that may specifically arise in older populations to provide optimal care. As we advance in understanding rosacea's pathogenesis and adopt personalized phenotype-based approaches, optimizing care for older patients becomes crucial. Continued research into novel treatments is essential to address their unique needs.

Erenumab for Treatment of Persistent Erythema and Flushing in Rosacea: A Nonrandomized Controlled Trial

Importance

Treatment of erythema and flushing in rosacea is challenging. Calcitonin gene-related peptide (CGRP) has been associated with the pathogenesis of rosacea, raising the possibility that inhibition of the CGRP pathway might improve certain features of the disease.

Objective

To examine the effectiveness, tolerability, and safety of erenumab, an anti-CGRP-receptor monoclonal antibody, for the treatment of rosacea-associated erythema and flushing.

Design, Setting, and Participants

This single-center, open-label, single-group, nonrandomized controlled trial was conducted between June 9, 2020, and May 11, 2021. Eligible participants included adults with rosacea with at least 15 days of either moderate to severe erythema and/or moderate to extreme flushing. No concomitant rosacea treatment was allowed throughout the study period. Visits took place at the Danish Headache Center, Copenhagen University Hospital, Rigshospitalet in Copenhagen, Denmark. Participants received 140 mg of erenumab subcutaneously every 4 weeks for 12 weeks. A safety follow-up visit was performed at week 20. Data analysis occurred from January 2023 to January 2024.

Intervention

140 mg of erenumab every 4 weeks for 12 weeks.

Main Outcomes and Measures

The primary outcome was mean change in the number of days with moderate to extreme flushing during weeks 9 through 12, compared with the 4-week run-in period (baseline). The mean change in number of days with moderate to severe erythema was a secondary outcome. Adverse events were recorded for participants who received at least 1 dose of erenumab. Differences in means were calculated with a paired t test.

Results

A total of 30 participants (mean [SD] age, 38.8 [13.1] years; 23 female [77%]; 7 male [23%]) were included, of whom 27 completed the 12-week study. The mean (SD) number of days with moderate to extreme flushing was reduced by -6.9 days (95% CI, -10.4 to -3.4 days; P < .001) from 23.6 (5.8) days at baseline. The mean (SD) number of days with moderate to severe erythema was reduced by -8.1 days (95% CI, -12.5 to -3.7 days; P < .001) from 15.2 (9.1) days at baseline. Adverse events included transient mild to moderate constipation (10 participants [33%]), transient worsening of flushing (4 participants [13%]), bloating (3 participants [10%]), and upper respiratory tract infections (3 participants [10%]), consistent with previous data. One participant discontinued the study due to a serious adverse event (hospital admission due to gallstones deemed unrelated to the study), and 2 participants withdrew consent due to lack of time.

Conclusions and Relevance

These findings suggest that erenumab might be effective in reducing rosacea-associated flushing and chronic erythema (participants generally tolerated the treatment well, which was consistent with previous data), and that CGRP-receptor inhibition holds potential in the treatment of erythema and flushing associated with rosacea. Larger randomized clinical trials are needed to confirm this finding.

Trial Registration

ClinicalTrials.gov Identifier: NCT04419259.

Vascularized 3D Human Skin Models in the Forefront of Dermatological Research

In vitro engineered skin models are emerging as an alternative platform to reduce and replace animal testing in dermatological research. Despite the progress made in recent years, considerable challenges still exist for the inclusion of diverse cell types within skin models. Blood vessels, in particular, are essential in maintaining tissue homeostasis and are one of many primary contributors to skin disease inception and progression. Substantial efforts in the past have allowed the successful fabrication of vascularized skin models that are currently utilized for disease modeling and drugs/cosmetics testing. This review first discusses the need for vascularization within tissue-engineered skin models, highlighting their role in skin grafting and disease pathophysiology. Second, the review spotlights the milestones and recent progress in the fabrication and utilization of vascularized skin models. Additionally, advances including the use of bioreactors, organ-on-a-chip devices, and organoid systems are briefly explored. Finally, the challenges and future outlook for vascularized skin models are addressed.

Clinical characteristics of the well-defined upper eyelid vascular network pattern in patients with rosacea

BACKGROUND

Rosacea is a chronic inflammatory skin disease. The diagnosis is based on the symptoms and physical signs, which still lacks objective laboratory tests or imaging tests.

OBJECTIVES

To propose and evaluate the upper eyelid network pattern in rosacea.

METHODS

Participants included patients diagnosed with rosacea, other facial erythematous skin diseases, and normal controls, all of whom underwent full-face imaging utilizing the VISIA® system software. According to these images, researchers evaluated the condition of the upper eyelid vascular network, developed the grading scale and then compared the difference of distribution in the three groups.

RESULTS

The occurrence rate of upper eyelid vascular network in rosacea was significantly higher than that in other facial erythematous skin diseases (84.3 vs. 32.0%, P < 0.001) and normal controls (84.3 vs. 28.0%, P < 0.001). The upper eyelid vascular network pattern was proposed (none [no clearly reticular vessels], mild [10-50% area of reticular vessels], moderate-to-severe [>50% area of reticular vessels]). Moderate-to-severe grade was defined as well-defined upper eyelid vascular network pattern, which was specific to patients with rosacea (rosacea vs. other facial erythematous skin diseases, adjusted odds ratio [aOR] = 5.814, 95% confidence interval [CI]: 3.899-8.670) (rosacea vs. heathy controls, aOR = 12.628, 95% CI: 8.334-19.112). The severity of the well-defined pattern had no significant association with age, duration, and phenotypes of rosacea (P > 0.05).

CONCLUSION

The well-defined upper eyelid vascular network pattern specifically appeared in patients with rosacea, which could be a possible clue to the diagnosis of rosacea.

Recent Advances in the Management of Rosacea through Natural Compounds

Rosacea is a chronic skin disorder that affects more than 5% of the world's population, with the number increasing every year. Moreover, studies show that one-third of those suffering from rosacea report a degree of depression and are less compliant with treatment. Despite being the subject of prolonged studies, the pathogenesis of rosacea remains controversial and elusive. Since most medications used for the management of this pathology have side effects or simply do not yield the necessary results, many patients lose trust in the treatment and drop it altogether. Thus, dermato-cosmetic products with natural ingredients are gaining more and more notoriety in front of synthetic ones, due to the multiple benefits and the reduced number and intensity of side effects. This review is a comprehensive up-to-date report of studies that managed to prove the beneficial effects of different botanicals that may be useful in the short and long-term management of rosacea-affected skin. Based on recent preclinical and clinical studies, this review describes the mechanisms of action of a large array of phytochemicals responsible for alleviating the clinical symptomatology of the disease. This is useful in further aiding and better comprehending the way plant-based products may help in managing this complex condition, paving the way for research in this area of study.

Integrated Omics Reveal the Molecular Characterization and Pathogenic Mechanism of Rosacea

Recent efforts have described the transcriptomic landscape of rosacea. However, little is known about its proteomic characteristics. In this study, the proteome and phosphoproteome of lesional skin, paired nonlesional skin, and healthy skin were analyzed by liquid chromatography coupled with tandem mass spectrometry. The molecular characteristics and potential pathogenic mechanism of rosacea were demonstrated by integrating the proteome, phosphoproteome, and previous transcriptome. The proteomic data revealed a significant upregulation of inflammation- and axon extension-related proteins in lesional skin and nonlesional skin versus in healthy skin, implying an inflammatory and nerve-hypersensitive microenvironment in rosacea skin. Of these, axon-related proteins (DPYSL2 and DBNL) were correlated with the Clinician's Erythema Assessment score, and neutrophil-related proteins (ELANE and S100A family) were correlated with the Investigator's Global Assessment score. Moreover, comorbidity-related proteins were differentially expressed in rosacea; of these, SNCA was positively correlated with Clinician's Erythema Assessment score, implying a potential correlation between rosacea and comorbidities. Subsequently, the integrated proteome and transcriptome demonstrated consistent immune disturbances at both the transcriptional and protein levels. The integrative analysis of the proteome and phosphoproteome revealed the key transcription factor network and kinase network that drive the dysregulation of immunity and vasculature in rosacea. In conclusion, our multiomics analysis enables more comprehensive insight into rosacea and offers an opportunity for, to our knowledge, previously unreported treatment strategies.

Evaluation of Dermatological and Neurological Aspects of the Relationship between Rosacea and Headaches

This study aimed to investigate the relationship between rosacea and headaches, focusing on different subtypes, as well as the associated clinical features and triggering factors. In this prospective study, 300 patients diagnosed with rosacea and 320 control subjects without rosacea or any connected mast cell activation illness were included. Patients with rosacea were assessed by a dermatologist according to the 2019 updated rosacea classification (ROSCO panel). Accordingly, patients were classified based on their predominant rosacea subtype as follows: erythematotelangiectatic (ETR), papulopustular (PPR), or phymatous (RhR). Patients experiencing headaches were assessed using the International Headache Classification. Headaches were categorized as migraine, tension-type headaches (TTHs), secondary types (STHs), and cluster-type headaches (CTHs). The ratio of headache was 30.3% in the rosacea group, which did not show a significant difference compared to the control group (30.3% vs. 25.0%, p = 0.138). In 81.3% of rosacea patients with headaches, headache onset occurred after the diagnosis of rosacea. The rate of patients with headaches was higher in the ETR group compared to the PPR and RhR groups (35.2% vs. 16.2% vs. 23.1%, p = 0.007, respectively). In terms of headache subtypes, the rates of patients with migraine and STHs were higher in the ETR group compared to the PPR and RhR groups, while the rate of patients with TTHs was higher in the RhR group. A positive correlation was found between rosacea severity and migraine severity (r = 0.284, p < 0.05). Among the triggering factors for rosacea, only sunlight was found to be associated with headaches. Lower age, female gender, and moderate to severe rosacea severity were identified as independent factors increasing the likelihood of headaches. A significant portion of rosacea patients experience headaches. Particularly, different subtypes of rosacea may be associated with various types of headaches. This study, highlighting the connection between migraine and ETR, is a pioneering work that demonstrates common pathogenic mechanisms and potential triggers.

Relationship Between Dermoscopic Capillary-Related Features of the Auricle and Earlobe and Rosacea Subtype and Disease Severity: A Cross-Sectional Analysis

Background and Aim

Clinical manifestations of rosacea include transient or persistent facial erythema, telangiectasia, papules, and pustules. The existing assessment tools primarily evaluate the facial area to assess the severity of rosacea. However, in addition to the face, telangiectasia, erythema, and flushing can occur in the ear. Here, we investigated the correlation between the dermoscopic characteristics of capillaries in the earlobe and auricle and the types and severity of rosacea.

Materials and Methods

Experienced dermatologists evaluated the clinical type, medical history, severity, and distribution pattern of facial erythema. The clinical severity of rosacea was assessed using the standard grading system (SGS), clinician's erythema assessment (CEA), and investigator's global assessment (IGA). Relationships of the clinical types and severity with the dermoscopic characteristics of capillaries in the earlobe and auricle were further analyzed.

Results

In total, 145 patients with rosacea were enrolled in this study. We found that SGS, CEA, and IGA correlated well with the dermoscopic features of capillaries in the earlobe (R = 0.357, 0.357, and 0.314, respectively) (p < 0.001) and auricle (R = 0.423, 0.443, and 0.374, respectively) (p < 0.001). However, there was no significant correlation between the features and types of rosacea.

Conclusion

The dermoscopic characteristics of capillaries in the earlobe and auricle can be used as indicators of the clinical severity of rosacea, regardless of the clinical subtype.

Effect of COVID-19 and Face Masks on the Condition of Rosacea - A Retrospective Analysis of 87 Patients

Introduction

The pathogenesis of COVID-19 includes systemic immune activation and endothelial dysfunction, which is closely related to the pathogenesis of rosacea. In order to investigate the influence of COVID-19 infection on the condition of rosacea patients, we retrospectively investigated the impact of COVID-19 infection and COVID-19-related masks on rosacea patients.

Methods

We collected the basic information from rosacea patients who had a long-term follow-up at West China Hospital of Sichuan University. Between January 2023 and March 2023, we recruited 87 rosacea patients for this survey.

Results

Our results showed that COVID-19 infection could aggravate the condition of rosacea patients, and the change in the symptoms was not related to fever, temperature, antipyretics use, and vaccination. In addition, we observed a significant association between the type of mask worn by rosacea patients and exacerbation, while the duration of mask usage did not exhibit a similar relationship.

Discussion

Considering the ongoing global utilization of masks due to the COVID-19 pandemic and the possible recurrence of COVID-19 infection, dermatologists should monitor the condition of rosacea patients infected with COVID-19 and adjust the treatment regimens accordingly.

TLR7 promotes skin inflammation via activating NFκB-mTORC1 axis in rosacea

Rosacea is a chronic inflammatory skin disease originated from damaged skin barrier and innate/adaptive immune dysregulation. Toll-like receptors (TLRs) sense injured skin and initiate downstream inflammatory and immune responses, whose role in rosacea is not fully understood. Here, via RNA-sequencing analysis, we found that the TLR signaling pathway is the top-ranked signaling pathway enriched in rosacea skin lesions, in which TLR7 is highlighted and positively correlated with the inflammation severity of disease. In LL37-induced rosacea-like mouse models, silencing TLR7 prevented the development of rosacea-like skin inflammation. Specifically, we demonstrated that overexpressing TLR7 in keratinocytes stimulates rapamycin-sensitive mTOR complex 1 (mTORC1) pathway via NFκB signaling. Ultimately, TLR7/NFκ B/mTORC1 axis promotes the production of cytokines and chemokines, leading to the migration of CD4+T cells, which are infiltrated in the lesional skin of rosacea. Our report reveals the crucial role of TLR7 in rosacea pathogenesis and indicatesa promising candidate for rosacea treatments.

Exploring the Pathogenesis and Mechanism-Targeted Treatments of Rosacea: Previous Understanding and Updates

Rosacea is a chronic inflammatory skin disease characterized by recurrent erythema, flushing, telangiectasia, papules, pustules, and phymatous changes in the central area of the face. Patients with this condition often experience a significant negative impact on their quality of life, self-esteem, and overall well-being. Despite its prevalence, the pathogenesis of rosacea is not yet fully understood. Recent research advances are reshaping our understanding of the underlying mechanisms of rosacea, and treatment options based on the pathophysiological perspective hold promise to improve patient outcomes and reduce incidence. In this comprehensive review, we investigate the pathogenesis of rosacea in depth, with a focus on emerging and novel mechanisms, and provide an up-to-date overview of therapeutic strategies that target the diverse pathogenic mechanisms of rosacea. Lastly, we discuss potential future research directions aimed at enhancing our understanding of the condition and developing effective treatments.

A Prospective Randomized Controlled Pilot Study to Assess the Response and Tolerability of Cold Atmospheric Plasma for Rosacea

INTRODUCTION

Rosacea is a common, facial, chronic inflammatory skin disease. Due to its complex pathogenesis, adequate therapy of rosacea can be challenging. An innovative recent therapeutic tool is cold atmospheric plasma (CAP), which is already established in the treatment of chronic wounds and promising in different other skin diseases.

METHODS

In a split-face pilot study we investigated dielectric-barrier-discharged CAP in erythemato-telangiectatic (ETR) and/or papulopustular rosacea (PPR). CAP treatment was applied on lesional skin of a randomized side once daily (90 s/area) for 6 weeks. The other untreated side served as control. Co-primary endpoints were ≥1 improvement of the Investigator Global Assessment (IGA) score on the treated side compared to control and a decline of the Dermatology Life Quality Index (DLQI) after 6 weeks. Secondary endpoints included inflammatory lesion count (papules and pustules), skin redness intensity and erythema size. Adverse events (AEs) were recorded constantly. Additionally, participants were weekly assessed for symptoms, skin condition, trigger factors, skin care, treatment success, and local tolerance parameters. All p values were calculated using the Wilcoxon signed-rank test.

RESULTS

Twelve subjects (ETR, n = 3; ETR and PPR, n = 9) completed the study. DLQI was significantly improved after 6 weeks (p = 0.007). On the CAP-treated side, lesions (p = 0.007) and erythema size (p = 0.041) were significantly reduced compared to the control. IGA (p = 0.2) and skin redness intensity (p = 0.5) did not differ significantly between control and CAP-treated side. No serious AEs occurred and treatment was well tolerated.

CONCLUSION

CAP is a promising new treatment of rosacea, especially for PPR.

Whole genome sequencing identifies genetic variants associated with neurogenic inflammation in rosacea

Rosacea is a chronic inflammatory skin disorder with high incidence rate. Although genetic predisposition to rosacea is suggested by existing evidence, the genetic basis remains largely unknown. Here we present the integrated results of whole genome sequencing (WGS) in 3 large rosacea families and whole exome sequencing (WES) in 49 additional validation families. We identify single rare deleterious variants of LRRC4, SH3PXD2A and SLC26A8 in large families, respectively. The relevance of SH3PXD2A, SLC26A8 and LRR family genes in rosacea predisposition is underscored by presence of additional variants in independent families. Gene ontology analysis suggests that these genes encode proteins taking part in neural synaptic processes and cell adhesion. In vitro functional analysis shows that mutations in LRRC4, SH3PXD2A and SLC26A8 induce the production of vasoactive neuropeptides in human neural cells. In a mouse model recapitulating a recurrent Lrrc4 mutation from human patients, we find rosacea-like skin inflammation, underpinned by excessive vasoactive intestinal peptide (VIP) release by peripheral neurons. These findings strongly support familial inheritance and neurogenic inflammation in rosacea development and provide mechanistic insight into the etiopathogenesis of the condition.

The Role of Cosmetology in an Effective Treatment of Rosacea: A Narrative Review

Rosacea is a chronic inflammatory facial skin disease usually occurring in middle-aged patients. It manifests itself as an inflammatory condition with perivascular infiltrate, dilated blood vessels, lymphoedema, hyperplasia of sebaceous glands, and disorders of connective tissue structures brought on by fibrosis. Rosacea is characterized by multifactorial inflammatory mechanisms, and therefore it requires an interdisciplinary approach including adequate skin care, topical and/or systemic therapy, and physical modalities to successfully treat the various symptoms and disease subtypes. However, data regarding the possible role of cosmetologists in rosacea remains scanty and equivocal. The objectives of cosmetology therapy include restoration and regeneration, anti-inflammatory effects, the strengthening of blood vessels and regulation of their permeability, and the regulation of keratinization. Vascular abnormalities can be targeted with specific light and laser devices. Therefore, the present paper aims to review the latest advances and summarize different aspects concerning skin care in rosacea. Particular attention has been paid to the co-operation of cosmetologists with other specialists in order to bring about the interdisciplinary management of rosacea. It is also important to keep in mind that it is usually necessary to combine various methods of treatment, as this approach is more effective than monotherapy for attaining satisfactory cosmetic results in rosacea patients.

Evaluation of inflammatory status in blood in patients with rosacea

Rosacea is a chronic inflammatory skin disease that is characterized by recurrent episodes of erythema, telangiectasia and papulopustular lesions. Although the pathogenesis is not well established, growing knowledge suggests that multiple etiological factors play a role resulting in inflammation. The aim of the present study is to investigate inflammatory status of patients with rosacea by evaluating CBC parameters and systemic immune inflammation (SII) index and compare these parameters with control group. Thus, it is aimed to understand the role of systemic inflammation in the pathogenesis of the disease. This retrospective, case-control study included 100 patients with rosacea and 58 sex- and age-matched controls. Laboratory examinations including CBC, ESR, CRP, HDL, LDL, and triglyceride levels were recorded and neutrophil-lymphocyte ratio (NLR), monocyte-lymphocyte ratio (MLR), and platelet-lymphocyte ratio (PLR), monocyte-to-high-density lipoprotein ratio (MHR) and SII index were calculated. Monocyte and platelet count, SII index, ESR and CRP were significantly higher in patients with rosacea than in the control group. No statistically significant difference was found in other parameters. There was no significant correlation between disease severity and ESR, CRP, and SII index. The findings of this study suggest that apart from the inflammatory pathways at the level of skin, there is an inflammatory state in the blood of patients. Rosacea is a skin disease, but it may have systemic implications and/or associations that need to be clarified completely.

Analysis of facial vascular pattern characteristics in the Korean population

BACKGROUND

Facial erythema is a common problem among patients visiting dermatologists. However, data on the clinical characteristics of facial erythema in healthy people are lacking. We aimed to compare and analyze the severity and pattern of facial vascularity in healthy subjects based on their age and gender.

MATERIALS AND METHODS

This study included 198 Korean volunteers (126 females and 72 males) with Fitzpatrick skin types II, III, or IV. Fourteen different anatomical areas on the face were divided into facial erythema units. Each unit was scored from one (least erythematous) to five (most erythematous) according to the observed level of erythema on the red images implemented as hemoglobin content. We also evaluated the presence of facial telangiectatic macules.

RESULTS

On average, the perinasal, nasal, and cheek units were the most hypervascular regions. In contrast, the degree of facial erythema was lowest in the labial (perioral), neck, and temporal regions. The average value of erythema was higher in males than in females. Additionally, the severity of erythema tended to increase with age. In both males and females, the number of telangiectatic macules increased with age.

CONCLUSIONS

We analyzed the clinical characteristics of erythema in healthy subjects with Fitzpatrick skin types II, III, or IV in the Korean population. This study is expected to be used to identify the neurovascular pathogenesis of the most common regions of facial dermatosis in the future.

GBP5 exacerbates rosacea-like skin inflammation by skewing macrophage polarization towards M1 phenotype through the NF-κB signalling pathway

BACKGROUND

Rosacea is a chronic inflammatory skin disease with increased macrophage infiltration. However, the molecular mechanism remains unclear.

OBJECTIVES

To determine the significance of macrophage infiltration, and the correlation between Guanylate-binding protein 5 (GBP5) and polarization of macrophages in rosacea-like inflammation.

METHODS

Here we tested the hypothesis that Guanylate-binding protein 5 (GBP5) aggravates rosacea-like skin inflammation by promoting the polarization of the M1 macrophages through the NF-κB signalling pathway. We depleted macrophage by injecting clodronate-containing liposomes. We next explored the association between GBP5 and macrophage in rosacea tissue through transcriptome analysis and immunofluorescence analysis. We evaluated the severity of rosacea-like skin inflammation when BALB/c mice were injected with GBP5 siRNA intradermally daily for three consecutive days. At last, to study the causality of knocking down GBP5-blunted M1 macrophage polarization, THP-1 cell was treated with GBP5 siRNA.

RESULTS

Macrophage depletion ameliorated rosacea-like skin inflammation in mice, implying the important role of macrophages in rosacea. Based on the transcriptome analysis, Guanylate-binding protein 5 (GBP5) was identified as hub gene that was associated with macrophage infiltration in rosacea. Next, we found that GBP5 expression was significantly upregulated in rosacea tissues and positively correlated with macrophage infiltration, the immunofluorescence analysis revealed the co-localization between GBP5 and macrophages. In vivo, silencing of GBP5 attenuated rosacea-like skin inflammation in the LL-37-induced mouse model and suppressed the expression of M1 signature genes such as IL-6, iNOS and TNF-a. In vitro, knocking down GBP5 significantly blunted the polarization of the M1 macrophages partly by repressing the activation of the NF-κB signalling pathways.

CONCLUSIONS

Together, our study revealed the important role of macrophages in rosacea and identified GBP5 as a key regulator of rosacea by inducing M1 macrophage polarization via NF-κB signalling pathways.

Elucidating the potential pharmaceutical mechanism of Gyejibokryeong-hwan on rosacea using network analysis

Rosacea is a chronic erythematous disease with telangiectasia that affects the central area of the face. However, because of the ambiguity in the pathophysiology of rosacea, its treatment has not been clearly elucidated; therefore, new therapeutic options need to be developed. Gyejibokryeong-hwan (GBH) is widely used in clinical practice for various blood circulation disorders, including hot flushes. Therefore, we explored the potential pharmaceutical mechanism of GBH on rosacea and investigated the therapeutic points exclusive to GBH through comparative analysis with chemical drugs recommended in 4 guidelines for rosacea based on network analysis. The active compounds in GBH were identified, and the proteins targeted by these compounds and the genes related to rosacea were searched. Additionally, the proteins targeted by the guideline drugs were also searched to compare their effects. And the pathway/term analysis of common genes was conducted. Ten active compounds were obtained for rosacea. There were 14 rosacea-related genes targeted by GBH, with VEGFA, TNF, and IL-4, which were suggested as core genes. The pathway/term analysis of the 14 common genes revealed that GBH could potentially act on rosacea via 2 pathways: the "interleukin 17 signaling pathway" and the "neuroinflammatory response." Comparison and analysis of the protein targets between GBH and guideline drugs revealed that only GBH separately acts on the "vascular wound healing pathway." GBH has the potential to act on IL-17 signaling pathway, neuroinflammatory response and vascular wound healing pathway. Further studies are needed to determine the potential mechanism of GBH in rosacea.

Type I IFNs link skin-associated dysbiotic commensal bacteria to pathogenic inflammation and angiogenesis in rosacea

Rosacea is a common chronic inflammatory skin disease with a fluctuating course of excessive inflammation and apparent neovascularization. Microbial dysbiosis with a high density of Bacillus oleronius and increased activity of kallikrein 5, which cleaves cathelicidin antimicrobial peptide, are key pathogenic triggers in rosacea. However, how these events are linked to the disease remains unknown. Here, we show that type I IFNs produced by plasmacytoid DCs represent the pivotal link between dysbiosis, the aberrant immune response, and neovascularization. Compared with other commensal bacteria, B. oleronius is highly susceptible and preferentially killed by cathelicidin antimicrobial peptides, leading to enhanced generation of complexes with bacterial DNA. These bacterial DNA complexes but not DNA complexes derived from host cells are required for cathelicidin-induced activation of plasmacytoid DCs and type I IFN production. Moreover, kallikrein 5 cleaves cathelicidin into peptides with heightened DNA binding and type I IFN-inducing capacities. In turn, excessive type I IFN expression drives neoangiogenesis via IL-22 induction and upregulation of the IL-22 receptor on endothelial cells. These findings unravel a potentially novel pathomechanism that directly links hallmarks of rosacea to the killing of dysbiotic commensal bacteria with induction of a pathogenic type I IFN-driven and IL-22-mediated angiogenesis.

Quality of life measurement in rosacea. Position statement of the European Academy of Dermatology and Venereology Task Forces on Quality of Life and Patient Oriented Outcomes and Acne, Rosacea and Hidradenitis Suppurativa

The European Academy of Dermatology and Venereology (EADV) Task Forces (TFs) on Quality of Life (QoL) and Patient-Oriented Outcomes and Acne, Rosacea and Hidradenitis Suppurativa (ARHS) do not recommend the use of any generic instrument as a single method of Health Related (HR) QoL assessment in rosacea, except when comparing quimp (quality of life impairment) in rosacea patients with that in other non-dermatologic skin diseases and/or healthy controls. The EADV TFs on QoL and Patient-Oriented Outcomes and ARHS recommend the use of the dermatology-specific HRQoL instrument the Dermatology Life Quality Index (DLQI) and the rosacea-specific HRQoL instrument RosaQoL in rosacea patients. The DLQI minimal clinically important difference may be used as a marker of clinical efficacy of the treatment and DLQI score banding of 0 or 1 corresponding to no effect on patients' HRQoL could be an important treatment goal. This information may be added to consensuses and guidelines for rosacea.

Mast cell stabilization: new mechanism underlying the therapeutic effect of intense pulsed light on rosacea

BACKGROUND

Rosacea, a chronic inflammatory disorder of the facial skin, is effectively treated by intense pulsed light (IPL).

OBJECTIVE

To explore the potential molecular mechanism underlying the photobiomodulation effect of IPL for rosacea treatment.

METHODS

Skin samples from patients with rosacea were subjected to histological and immunohistological staining. Ten patients were followed up after IPL treatment using the VISIA^® skin analysis system, and the severity was assessed. In vivo, skin changes in mice with rosacea-like inflammation induced by intradermal injection of 320 μM LL-37 with or without IPL treatment were evaluated using L*a*b colorimetry as well as histological and immunological staining. In vitro, LL-37-stimulated mast cells (MCs) with or without IPL treatment were evaluated for protein expression of matrix metalloproteinase (MMP)-9, kallikrein-related peptidase 5 (KLK5), and cathelicidin using western blotting and qRT-PCR.

RESULTS

Profound infiltration of inflammatory cells and evident MC degranulation were found in rosacea skin lesions. The expression of rosacea-related biomarkers and inflammatory cytokines was higher in lesional areas than in non-lesional areas, as demonstrated via immunochemical staining. In all patients, rosacea severity reduced after IPL therapy. In vivo, IPL alleviated inflammation in mice with rosacea-like inflammation, as demonstrated by the significantly decreased MMP-9, KLK5, and cathelicidin expression and reduced percentage of degranulating MCs. In vitro, IPL decreased MMP-9, KLK5, and cathelicidin expression in P815 cells, reducing the release of inflammatory cytokines and inhibiting rosacea-like inflammatory reactions.

CONCLUSION

The photobiomodulation effect of IPL for rosacea treatment may inhibit MC degranulation and alleviate inflammatory reactions.

Novel technique for rosacea treatment using optimal pulse technology: In vivo and clinical studies

BACKGROUND

Rosacea is a chronic inflammatory skin disease affecting the face, and the current treatment effect is not satisfactory. Based on the photomodulation of optimal pulse technology (OPT), we developed a novel treatment mode, namely, advanced OPT with low energy, three pulses, and long pulse width (AOPT-LTL).

AIMS

We aimed to explore the feasibility and underlying molecular mechanisms of AOPT-LTL treatment in a rosacea-like mouse model. Furthermore, we evaluated the safety and efficacy in patients with erythematotelangiectatic rosacea (ETR).

MATERIALS AND METHODS

Morphological, histological, and immunohistochemical analyses were used to investigate the efficacy and mechanisms of AOPT-LTL treatment in the LL-37-induced rosacea-like mouse model. Moreover, 23 patients with ETR were included and received different times of treatment at intervals of 2 weeks depending on the severity of their condition. The treatment effect was assessed by comparing clinical photographs at baseline, 1 week, and 3 months after treatment, combined with the red value, GFSS, and CEA scores.

RESULTS

After the AOPT-LTL treatment of the mice, we observed that the rosacea-like phenotype, inflammatory cell infiltration, and vascular abnormalities were significantly ameliorated, and the expression of the core molecules of rosacea was significantly inhibited. In the clinical study, the AOPT-LTL treatment exerted satisfactory therapeutic effects on erythema and flushing of ETR patients. No serious adverse events were observed.

CONCLUSIONS

AOPT-LTL is a safe and effective method for the treatment of ETR.

Aberrant amino acid metabolism promotes neurovascular reactivity in rosacea

Rosacea is a chronic skin disorder characterized by abnormal neurovascular and inflammatory conditions on the central face. Despite increasing evidence suggesting that rosacea is associated with metabolic disorders, the role of metabolism in rosacea pathogenesis remains unknown. Here, via a targeted metabolomics approach, we characterized significantly altered metabolic signatures in patients with rosacea, especially for amino acid-related metabolic pathways. Among these, glutamic acid and aspartic acid were highlighted and positively correlated with the disease severity in patients with rosacea. We further demonstrated that glutamic acid and aspartic acid can facilitate the development of erythema and telangiectasia, typical features of rosacea, in the skin of mice. Mechanistically, glutamic acid and aspartic acid stimulated the production of vasodilation-related neuropeptides from peripheral neurons and keratinocytes and induced the release of nitric oxide from endothelial cells and keratinocytes. Interestingly, we provided evidence showing that doxycycline can improve the symptoms of patients with rosacea possibly by targeting the amino acid metabolic pathway. These findings reveal that abnormal amino acid metabolism promotes neurovascular reactivity in rosacea and raise the possibility of targeting dysregulated metabolism as a promising strategy for clinical treatment.

The temperature-sensitive receptors TRPV4 and TRPM8 have important roles in the pruritus of rosacea

BACKGROUND

Certain sensations are the secondary phenotypes of rosacea and affect patients' quality of life. Transient receptor potential (TRP) channels may be involved in its occurrence. However, there is a lack of research independently discussing itch in rosacea.

OBJECTIVES

Our study aimed to investigate risk factors for pruritus in rosacea patients and to discover the molecular mechanism of pruritus.

METHODS

A binary logistic regression model was used to identify significant variables affecting pruritus in 782 rosacea patients. The LL-37 was injected intradermally into the face of mice to establish the animal model. qRT-PCR, immunohistochemistry and immunofluorescence were used to analyse the expression differences in pruritus-related molecules in mouse skin and the corresponding trigeminal ganglion (TG) between pruritus and nonpruritus groups.

RESULTS

The incidence of pruritus in rosacea was 42.46%, and the incidence of other symptoms increased with pruritus. Temperature effects were prominently related to the itch sensation of rosacea. Intradermal injection of LL-37 not only caused rosacea-like facial lesions but also induced a behavioural pattern indicative of pruritus. Increased expression of the temperature-sensitive receptors TRPV4 and TRPM8 was found in pruritic mouse skin and TG and human skin samples.

CONCLUSIONS

In rosacea patients, pruritus occurs frequently along with burning, flushing and sensitivity, most likely due to changes in temperature. The temperature-sensitive receptors TRPV4 and TRPM8 are both involved in the mechanism of pruritus in rosacea.

Clinical characteristics of combined rosacea and migraine

Background

An overlap between the skin disease rosacea and the headache disease migraine has been established; however, the magnitude of this overlap and the distribution between subtypes/phenotypes remains unclear.

Objective

The aim was to determine the magnitude of the overlap between rosacea and migraine, and to determine which subtypes/phenotypes were present in patients with concomitant rosacea and migraine.

Methods

In this cross-sectional study, 604 patients with a diagnosis of either rosacea or migraine were phenotyped through a face-to-face interview with clinical examination, to determine prevalence and phenotype of rosacea, and prevalence and subtype of migraine.

Results

We found a prevalence of migraine of 54% in patients with rosacea, and a prevalence of rosacea of 65% in patients with migraine. Concomitant migraine was significantly associated with the rosacea features flushing (odds ratio = 2.6, 95% confidence interval = 1.4–4.7, p = 0.002), ocular symptoms (odds ratio = 2.4, 95% confidence interval = 1.5–3.9, p < 0.001), and burning (odds ratio = 2.1, 95% confidence interval = 1.3–3.4, p = 0.002), whereas papules/pustules were inversely related with concomitant migraine (odds ratio = 0.5, 95% confidence interval = 0.3–0.8, p = 0.006). No association was found between concomitant migraine and centrofacial erythema, rhinophyma, telangiectasia, edema, or dryness. Concomitant rosacea was not associated with any specific migraine subtype in patients with migraine.

Conclusion

This study highlights a substantial overlap between rosacea and migraine, particularly in patients with certain rosacea features. Individuals with rosacea should be asked about concomitant migraine, and comorbidities should be considered when choosing between treatments.

A cream containing the sap of oat plantlets and mandarin extract soothes the symptoms of rosacea and improves the quality of life of patients

BACKGROUND

Rosacea is a chronic inflammatory disease of the facial skin that affects all skin types and occurs mostly in adults. The main clinical sign of rosacea is a characteristic and persistent form of centro-facial erythema that is prone to exacerbation and can impair quality of life (QoL). The current therapeutic approach for rosacea is to combine various treatments, use appropriate skincare products and avoid flare-up triggers.

OBJECTIVE

To evaluate the use of a facial skincare product containing protein-free sap extruded from Rhealba® oat plantlets and mandarin extract in subjects with rosacea.

METHODS

Three clinical studies were conducted in adult subjects with various rosacea phenotypes (erythematotelangiectatic or papulopustular) and treatment histories to assess the dermatological and ophthalmological tolerance of the study product, as well as its clinical effectiveness, after a twice-daily application on the whole face and neck for up to 4 weeks.

RESULTS

Tolerance of the product was rated as good to very good by dermatologists across the three studies, which involved a total of 105 evaluable subjects. Subjects with untreated erythematotelangiectatic rosacea reported fewer functional signs and symptoms of the disease and an improved QoL. The evaluation of skin biometric parameters revealed a reduction in transepidermal water loss, indicating that the study product helped to restore skin barrier integrity after 4 weeks, and a higher skin pH, indicating that the cutaneous microbiote was respected. Most subjects (93%) who had either undergone a superficial dermatological procedure for erythematotelangiectatic rosacea or were taking oral/topical treatments for papulopustular rosacea, rated the study product as very good (8/10) and felt it further relieved their symptoms.

CONCLUSION

Overall, the study product was very well tolerated and may be beneficial for subjects with rosacea as an adjunct to superficial dermatological procedures or oral/topical therapies, in line with the current recommendations for rosacea management.

Carvedilol ameliorates persistent erythema of erythematotelangiectatic rosacea by regulating the status of anxiety/depression

The treatment of persistent erythema and rosacea flushing is extremely challenging, especially for patients with anxiety. The aim of this study was to verify the efficacy of carvedilol in rosacea patients with persistent erythema and flushing. A total of 156 patients were randomized to use oral carvedilol 5 mg bid (twice per day) (n = 105) or topical brimonidine (n = 51) for a 10-week period with 6 weeks of follow-up. Both the efficacy of carvedilol and the status of anxiety/depression were analyzed by patient self-assessment (PSA), clinician erythema assessment (CEA), generalized anxiety disorder (GAD-7), and patient health questionnaire-9 (PHQ-9). Our study found that carvedilol exerted a dramatic reduction in CEA/PSA scores and sting/burning sensation scores in comparison to topical brimonidine. Additionally, carvedilol treatment dramatically improved telangiectasia, erythema, and pigmentation with no obvious side effects. Patients with carvedilol treatment showed an improvement of depression/anxiety, as reflected by lower GAD-7 and PHQ-9 scores than patients with topical brimonidine. Notably, we found carvedilol treatment had better outcomes among patients under 30 years of age with rosacea younger than 30 years old. Conclusively, our findings reveal that carvedilol could quickly and effectively improve facial erythema, which might stem from the improved the status of anxiety/depression.

Clinical clues to identify patients with ocular rosacea - a Germany-wide epidemiologic analysis

BACKGROUND AND OBJECTIVES

Ocular rosacea is a special manifestation of rosacea with unknown etiology. Eye involvement in rosacea patients is surprisingly common; however, it is often underdiagnosed, resulting in inappropriate treatment. We aimed to provide an updated epidemiologic perspective on ocular rosacea in Germany to improve patient care.

PATIENTS AND METHODS

Data of 777 rosacea patients were assessed using a detailed online questionnaire regarding ocular and skin symptoms, previous dermatological and ophthalmological consults, presence of type 1 hypersensitivities, and Demodex testing. All data were statistically analyzed.

RESULTS

Most patients reported ocular symptoms (399/777, 51.4%), including red eyes (179/399, 44.9%), itching (187/399, 46.9%), sty or chalazion (309/399, 77.4%), and dryness (108/399, 27.1%). Ocular rosacea was confirmed in 149/309 cases who consulted an ophthalmologist (45.3%). A total of 159/399 (39.8%) had no pre-existing allergies. Eye involvement was significantly associated with the presence of skin symptoms (P < 0.05), impacting patients' general well-being and overall treatment satisfaction. About half of Demodex-positive patients (21/45, 46.7%) showed ocular symptoms.

CONCLUSIONS

Eye involvement in rosacea patients was common, often presenting with unspecific symptoms.

The Trinity of Skin: Skin Homeostasis as a Neuro–Endocrine–Immune Organ

For a long time, skin was thought to be no more than the barrier of our body. However, in the last few decades, studies into the idea of skin as an independent functional organ have gradually deepened our understanding of skin and its functions. In this review, we gathered evidence that presented skin as a “trinity” of neuro–endocrine–immune function. From a neuro perspective, skin communicates through nerves and receptors, releasing neurotrophins and neuropeptides; from an endocrine perspective, skin is able to receive and secrete most hormones and has the cutaneous equivalent of the hypothalamic-pituitary-adrenal (HPA) axis; from an immune perspective, skin is protected not only by its physical barrier, but also immune cells and molecules, which can also cause inflammation. Together as an organ, skin works bidirectionally by operating peripheral neuro–endocrine–immune function and being regulated by the central nervous system, endocrine system and immune system at the same time, maintaining homeostasis. Additionally, to further explain the “trinity” of cutaneous neuro–endocrine–immune function and how it works in disease pathophysiology, a disease model of rosacea is presented.

Rosacea and Dry Eye Disease

Ocular rosacea is a chronic potentially sight-threatening inflammatory condition, which can occur in approximately 20% of patients without skin involvement. However, an accurate diagnosis of ocular rosacea has not been defined yet due to its rather nonspecific symptoms and clinical findings. Therefore, this article updates the current recommendations for diagnosis and treatment of ocular rosacea and the previously published consensus recommendations from the ROSCO expert panel on the management of rosacea.

Association of rosacea with depression and anxiety: A systematic review and meta-analysis

BACKGROUND

Rosacea is associated with several comorbidities, but its relationship with psychiatric disorders remains controversial. We aimed to investigate the association of rosacea with depression and anxiety.

METHODS

A systematic review was performed of relevant observational studies in the PubMed, Web of Science, Embase, and Wanfang databases from inception to June 8, 2021. The inclusion criteria for eligible studies were observational studies comparing the incidence or prevalence of depression or anxiety between patients with rosacea and individuals without rosacea. We conducted meta-analyses with a random-effects model. The main outcome was pooled analysis of prevalence or incidence of depression and anxiety in patients with rosacea.

RESULTS

We included nine studies with 101,114,209 patients with rosacea. A pooled analysis from cross-sectional and case-control studies revealed that patients with rosacea were significantly more likely to have depression (crude odds ratio [OR], 2.855; 95% confidence interval [CI], 1.258-6.481) and anxiety (crude OR, 2.373; 95% CI, 1.448-3.888) than matched controls; however, adjusted ORs showed no significant association. Furthermore, the meta-analysis from cohort studies indicated that patients with rosacea have significantly higher risks of developing depression (adjusted incidence rate ratio [IRR], 2.443; 95% CI, 1.603-3.723) and anxiety (adjusted IRR, 2.181; 95% CI, 1.660-2.864).

LIMITATIONS

Data for a subgroup analysis based on different demographic factors were insufficient.

CONCLUSIONS

Current findings provide more evidence that rosacea is significantly associated with depression and anxiety, and rosacea may predispose patients to develop depression and anxiety. Clinicians should be aware of the psychological aspects of rosacea.

Dermo-cosmetic spray containing Rhealba oat plantlets and Uncaria tomentosa extract in patients with mild-to-moderate cutaneous pain

BACKGROUND

Chronic cutaneous pain has a substantial negative impact on quality of life (QoL). Dermo-cosmetics can support therapies for treatment of chronic skin diseases, providing symptomatic relief from chronic cutaneous pain and improved QoL.

OBJECTIVES

To assess the global tolerance and efficacy of a dermo-cosmetic spray containing Rhealba^® Oat Plantlet and Uncaria tomentosa extracts in reducing cutaneous pain when used as a monotherapy or in association with drug or dermo-cosmetic treatments in patients with an underlying skin pathology.

METHODS

Patients aged ≥1 month with a cutaneous pain level ≥3 and an underlying skin pathology were provided with the spray to use up to six times daily for 6-8 weeks. Immediate effect on cutaneous pain and patient satisfaction were assessed after the first application. Global efficacy and tolerance, reduction in symptoms, improvement in QoL, pain reduction and patient overall satisfaction were assessed after 6-8 weeks.

RESULTS

Immediately after the first application, significant reductions in cutaneous pain were observed across all age groups (P < 0.0001), with 94% of patients reporting a reduction in pain. After 6-8 weeks, global tolerance was rated 'very good' or 'good' for 97% of patients, and the spray was efficacious in 95% of patients. Patient satisfaction with the efficacy of the spray was 95%. QoL scores improved in 86% and 94% of patients aged ≥12 and <12 years, respectively. Findings were similar across underlying pathology and therapy types (monotherapy or in association with another therapy).

CONCLUSIONS

The spray was well-tolerated and efficacious in providing symptom relief in patients with mild-to-moderate cutaneous pain, irrespective of the underlying pathology or therapy type.

mTORC1-Mediated Angiogenesis is Required for the Development of Rosacea

Although multiple evidences suggest that angiogenesis is associated with the pathophysiology of rosacea, its role is still in debate. Here, we showed that angiogenesis was enhanced in skin lesions of both rosacea patients and LL37-induced rosacea-like mice. Inhibition of angiogenesis alleviated LL37-induced rosacea-like features in mice. Mechanistically, we showed that mTORC1 was activated in the endothelial cells of the lesional skin from rosacea patients and LL37-induced rosacea-like mouse model. Inhibition of mTORC1 decreased angiogenesis and blocked the development of rosacea in mice. On the contrary, hyperactivation of mTORC1 increased angiogenesis and exacerbated rosacea-like phenotypes. Our in vitro results further demonstrated that inhibition of mTORC1 signaling significantly declined LL37-induced tube formation of human endothelial cells. Taken together, our findings revealed that mTORC1-mediated angiogenesis responding to LL37 might be essential for the development of rosacea and targeting angiogenesis might be a novel potential therapy.

The Effect of Capsaicin on Neuroinflammatory Mediators of Rosacea

Background

Rosacea is a chronic inflammatory skin disease with a pathophysiological mechanism that remains unclear. Recently, dysregulation of the sensory nerve system has been implicated in the development of this condition.

Objective

This study aimed to investigate the effect of capsaicin on neuroinflammatory mediators in rosacea. In addition, this study aimed to evaluate the attenuating effects of capsazepine, a transient receptor potential vanilloid type 1 (TRPV1) antagonist.

Methods

We obtained skin tissue from both rosacea patients and normal individuals for an in vivo study. In addition, normal human epidermal keratinocytes (NHEKs) were cultured, and treated with capsaicin and capsazepine for an in vitro study. Quantitative changes in neuroinflammatory mediators were evaluated by semi-quantitative reverse transcription-polymerase chain reaction (PCR), real-time PCR, enzyme-linked immunosorbent assay, and immunofluorescence staining.

Results

The data showed the increase of TRPV1, TRPV4, cathelicidin (LL37) and tumor necrosis factor-α (TNF-α) in skin tissue by real-time PCR. In addition, the data showed that cathelicidin (LL37), kallikrein-5 (KLK-5), TNF-α, vascular endothelial growth factor (VEGF), interleukin (IL)-1α, IL-1β, IL-8, and protease-activated receptor 2 (PAR2) increased in capsaicin-treated NHEKs. Capsazepine attenuated the expression of TRPV1 and other mediators, except for IL-8, in capsaicin-treated NHEKs.

Conclusion

We confirmed that TRPV1, TRPV4, cathelicidin (LL37) and TNF-α are increased in rosacea skin, and that capsaicin is associated with increase of neuroinflammatory mediators such as LL37, KLK-5, TNF-α, VEGF, IL-1α, IL-1β, IL-8, and PAR2. Modulators or inhibitors of neuroinflammatory mediators including TRPV1 could be potential therapeutic option in the treatment of patients with rosacea.

Bioinformatics and Network Pharmacology Identify the Therapeutic Role and Potential Mechanism of Melatonin in AD and Rosacea

Rosacea is significantly associated with dementia, particularly Alzheimer’s disease (AD). However, the common underlying molecular mechanism connecting these two diseases remains limited. This study aimed to reveal the common molecular regulatory networks and identify the potential therapeutic drugs for rosacea and AD. There were 747 overlapped DEGs (ol-DEGs) that were detected in AD and rosacea, enriched in inflammation-, metabolism-, and apoptosis-related pathways. Using the TF regulatory network analysis, 37 common TFs and target genes were identified as hub genes. They were used to predict the therapeutic drugs for rosacea and AD using the DGIdb/CMap database. Among the 113 predicted drugs, melatonin (MLT) was co-associated with both RORA and IFN-γ in AD and rosacea. Subsequently, network pharmacology analysis identified 19 pharmacological targets of MLT and demonstrated that MLT could help in treating AD/rosacea partly by modulating inflammatory and vascular signaling pathways. Finally, we verified the therapeutic role and mechanism of MLT on rosacea in vivo and in vitro. We found that MLT treatment significantly improved rosacea-like skin lesion by reducing keratinocyte-mediated inflammatory cytokine secretion and repressing the migration of HUVEC cells. In conclusion, this study contributes to common pathologies shared by rosacea and AD and identified MLT as an effective treatment strategy for rosacea and AD via regulating inflammation and angiogenesis.

Exploring metformin as a candidate drug for rosacea through network pharmacology and experimental validation

Rosacea is a common chronic inflammatory disease that affects the middle of the face. Due to the unclear pathogenesis, the effective treatment options for rosacea remain limited. In this study, weighted gene co-expression network analyses (WGCNA) identified three rosacea-related hub modules, which were involved in immune-, metabolic- and development- related signaling pathways. Next, the key genes from green and brown modules were submitted to CMap database for drug prediction and metformin was identified as a candidate drug for rosacea. Moreover, network pharmacology analysis identified pharmacological targets of metformin and demonstrated that metformin could help in treating rosacea partly by modulating inflammatory and angiogenesis signaling pathways. Finally, we verified the therapeutic role and mechanism of metformin on rosacea in vivo and vitro. We found that metformin treatment significantly improved rosacea-like skin lesions including immune cells infiltration, cytokines/chemokines expression and angiogenesis. Moreover, metformin suppressed LL37- and TNF-α-induced the ROS production and MAPK-NF-κB signal activation in keratinocytes cells. In conclusion, our findings identified and verified metformin as a novel therapeutic candidate for rosacea, and it alleviates the pathological symptoms, possibly by suppressing inflammatory responses, angiogenesis in rosacea.

Increased Frequency of Circulating Classical Monocytes in Patients with Rosacea

Purpose

Monocyte subsets, including classical, intermediate and non-classical monocytes, are involved in the pathogenesis of inflammatory or autoimmune diseases. The pathogenic role of monocytes in the peripheral blood mononuclear cells (PBMCs) of patients with rosacea remains unclear. This study aimed to assess frequencies of monocyte subsets in PBMCs from rosacea patients before and after clinical treatment.

Patients and Methods

We applied flow cytometry to examine frequencies of monocyte subsets in 116 patients with rosacea, while patients with 26 systemic lupus erythematosus (SLE), 28 acne and 42 normal healthy subjects without skin problems (HC) were recruited as controls. Expression of C–C chemokine receptor 2 (CCR2) on monocytes and plasma levels of CC-chemokine ligand 2 (CCL2), high mobility group box-1 (HMGB-1), interleukin-1 beta (IL-1β) and tumor necrosis factor alpha (TNF-α) were measured in HC and rosacea patients before and after treatment.

Results

The frequency of classical monocytes, but not intermediate or non-classical monocytes, was higher in rosacea as compared with HC, which decreased after treatment. Frequencies of monocyte subsets showed no gender difference, while increased with age in patients but not in HC. Frequencies of classical monocytes in patients with erythematotelangiectatic rosacea (ETR) and ETR-papulopustular rosacea (PPR) overlap were significantly higher than HC or patients with only PPR or phymatous rosacea (PhR). There was a significant higher expression of CCR2 in classical monocytes, with higher plasma levels of CCL2, HMGB-1, IL-1β and TNF-α in patients than in HC, which all significantly decreased after treatment.

Conclusion

Our data indicated a possible association between abnormal classical monocytes frequencies and rosacea.

Roles of calcitonin gene-related peptide in the skin, and other physiological and pathophysiological functions

Skin immunity is regulated by many mediator molecules. One is the neuropeptide calcitonin gene-related peptide (CGRP). CGRP has roles in regulating the function of components of the immune system including T cells, B cells, dendritic cells (DCs), endothelial cells (ECs), and mast cells (MCs).

Herein we discuss actions of CGRP in mediating inflammatory and vascular effects in various cutaneous models and disorders.

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CGRP can help to recruit immune cells through endothelium-dependent vasodilation.

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CGRP plays an important role in the pathogenesis of neurogenic inflammation.

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Functions of many components in the immune system are influenced by CGRP.

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CGRP regulates various inflammatory processes in human skin by affecting different cell-types.

Rosacea pathogenesis, common triggers, and dietary role: The cause, the trigger, and the positive effects of different foods

Rosacea is a common chronic inflammatory cutaneous disorder, primarily manifesting on the cheeks, nose, chin, and forehead with a classic relapsing-remitting course that affects mostly fair skin types (Fitzpatrick I and II). The pathogenesis remains unclear, but the complex interplay between environmental and genetic factors may augment the innate immune response and neurovascular dysregulation. Different nutrients may play a role in the pathogenesis of rosacea. Many dietary triggers, including hot beverages, alcohol, spicy foods, caffeine, vanilla, cinnamon, niacin, marinated meats, and dairy products, have been postulated for this disease; however, there is a lack of well-designed and controlled studies evaluating the causal relationship between rosacea and dietary factors. We have explored the available evidence and hypotheses based on trigger-food categories of rosacea, the role of the skin-gut microbiome axis, and potentially benefiting dietary factors such as probiotics, prebiotics, and high-fiber diets.

Cannabinoids interaction with transient receptor potential family and implications in the treatment of rosacea

With the recent interest in medical marijuana, research into cannabinoids is regaining wider attention. Cannabinoids are collectively a group of active compounds that can be produced by animals (endocannabinoids), plants (phytocannabinoids), or synthetically. By acting on a number of different receptors like cannabinoids receptors and transient receptor potential ion channel family, cannabinoids are known to modulate cutaneous inflammation, pain, and itch. Rosacea is a highly prevalent disease and can be associated with a significant degree of morbidity associated with its symptom. Transient receptor potential ion channels are known to be triggered in rosacea and may underlie a portion of rosacea's pathophysiology. This article aims to detail the transient receptor potential channel pathways in rosacea and the known effects of cannabinoids on these pathways and further discussing the potential role of cannabinoids in treating rosacea.

Prevalence of Helicobacter pylori Infection Among Rosacea and Chronic Spontaneous Urticaria Patients in a Tertiary Hospital in Riyadh, Saudi Arabia

BACKGROUND

The multifactorial nature of rosacea and chronic spontaneous urticaria (CSU) pathogenesis complicates the achievement of satisfactory treatment outcomes. 13C urea breath test (UBT) has been identified as an accurate, non-invasive, and quick procedure to detect the presence of Helicobacter pylori (H. pylori) with high sensitivity and specificity.

OBJECTIVE

In this study, we aim to assess the correlation between H. pylori infection and rosacea and CSU patients.

METHODS

A cross-sectional, observational study was conducted on patients with rosacea and CSU in the dermatology clinic at King Khalid University Hospital in Riyadh, Saudi Arabia. History and physical examination were performed by a dermatologist. H. pylori 13C-UBT detection was performed in all subjects.

RESULTS

In total, 114 patients were included in this current study, with 41 rosacea and 73 urticaria patients. The vast majority of our subjects were females (96.5%). The mean (±SD) age was 42.3 (±12.7). More than half (58.8%) of the examined samples were positive for 13C-UBT; however, positive results were significantly higher in the rosacea patients (73.2%) compared to the urticaria group (50.7%), with a p-value of 0.019.

CONCLUSION

Our findings underline the significant association of H. pylori with rosacea and CSU regardless of the presence or absence of gastrointestinal symptoms. We thus recommend the inclusion of H. pylori testing in the routine workup of CSU and rosacea patients.

Association of Rosacea With Cardiovascular Disease: A Retrospective Cohort Study

Background There is emerging evidence that rosacea, a chronic cutaneous inflammatory disease, is associated with various systemic diseases. However, its association with cardiovascular disease (CVD) remains controversial. We aimed to investigate whether patients with rosacea are at increased risk of developing CVD. Methods and Results This retrospective cohort study from the Korean National Health Insurance Service-Health Screening Cohort included patients with newly diagnosed rosacea (n=2681) and age-, sex-, and index year-matched reference populations without rosacea (n=26 810) between 2003 and 2014. The primary outcome was subsequent CVD including coronary heart disease and stroke. Multivariable Cox regression analyses were used to evaluate adjusted hazard ratios for subsequent CVD adjusted for major risk factors of CVD. Compared with the reference population (13 410 women; mean [SD] age, 57.7 [9.2] years), patients with rosacea (1341 women; mean [SD] age, 57.7 [9.2] years) displayed an increased risk for CVD (adjusted hazard ratios, 1.20; 95% CI, 1.03-1.40) and coronary heart disease (adjusted hazard ratios, 1.29; 95% CI, 1.05-1.60). The risk for stroke was not significantly elevated (adjusted hazard ratios, 1.12; 95% CI, 0.91-1.37). Conclusions This study suggests that patients with rosacea are more likely to develop subsequent CVD. Proper education for patients with rosacea to manage other modifiable risk factors of CVD along with rosacea is needed.

Alarmins/stressorins and immune dysregulation in intractable skin disorders

Unlike other barrier epithelia of internal organs, the stratified squamous epithelium of the skin is always exposed to the external environment. However, the robust barrier structure and function of the skin are highly resistant against external insults so as to not easily allow foreign invasions. Upon sensing danger signals, the innate immunity system is promptly activated. This process is mediated by alarmins, which are released passively from damaged cells. Nuclear alarmins or stressorins are actively released from intact cells in response to various cellular stresses. Alarmins/stressorins are deeply involved in the disease processes of chronic skin disorders of an unknown cause, such as rosacea, psoriasis, and atopic dermatitis. Furthermore, alarmins/stressorins are also induced in the congenital skin disorders of ichthyosis and keratoderma due to defective keratinization. Studies on alarmin activation and its downstream pathways may help develop novel therapeutic agents for intractable skin disorders.

Alcohol consumption and the risk of rosacea: A systematic review and meta-analysis

BACKGROUND

Rosacea is a chronic inflammatory skin disease that affects people's life quality. It has been found to be related to many detrimental factors including ultraviolet exposure. However, the association between alcohol consumption and rosacea has long been debated.

AIMS

To elucidate this association, we conducted a systematic review and meta-analysis.

METHODS

We performed a systematic search of the literature published before February 16, 2021 on PubMed, Embase, and the Cochrane database and used a meta-analytic approach to calculate the pooled odds ratios (ORs) and the corresponding 95% confidence intervals (CIs).

RESULTS

Finally, 14 eligible studies were identified, and alcohol consumption was not found to be a risk factor for rosacea. However, in subgroup analysis, alcohol consumption increased the risk of phymatous rosacea (PhR) and the pooled OR was 4.17 (95% CI = 1.76-9.91).

CONCLUSION

Overall, our study showed that alcohol consumption was a risk factor in phymatous rosacea (PhR). More studies of rosacea investigating sex distribution, alcohol intake levels, and types of alcoholic beverages consumed are needed in the future.

Does Rosacea, a localized skin disease, affect the choroidal thickness?

INTRODUCTION

This study aims to compare the choroidal thickness (CT) of patients with rosacea with healthy individuals.

METHODS

This study was conducted with 42 patients with Papulopustular Rosacea (PPR), 38 patients with Erythematotelangiectatic Rosacea (ETR), and gender and age-matched 37 healthy individuals in the control group. CT measurements were done using the spectral-domain optical coherence tomography.

RESULTS

Choroidal thickness means were measured as 352 ± 78 μm, 331 ± 67 μm, and 346 ± 83 μm at the subfoveal region; 323 ± 72.3 μm, 303.5 ± 68.4 μm, and 314 ± 80.3 μm at 1000 μm nasal; and 325.2 ± 71 μm, 304.4 ± 52.2 μm, and 309 ± 67 μm at 1000 μm temporal in the PPR, ETR, and control groups, respectively (p > 0.05).

CONCLUSION

Although rosacea is a common chronic skin disease that could have systemic findings, CT is not affected by this disease.