Integrative concepts of rosacea pathophysiology, clinical presentation and new therapeutics

Assessment of Vascular Circulation in Alopecia Areata Using the FMSF Technique

Background: Alopecia areata is regarded as a T cell-mediated autoimmune disorder, but the exact etiopathogenesis of the disease has not been completely elucidated. The aim of the study was to assess vascular circulation using Flow-Mediated Skin Fluorescence (FMSF) in alopecia patients compared to healthy volunteers, which could explain disease pathogenesis. Methods: FMSF is a new non-invasive method for assessing vascular circulation. The study recruited thirty women and four men. In our group, the most common clinical pattern of hair loss was alopecia with circular patches (AA), recognizable in 26 patients: twenty-two women and four men. Alopecia universalis (AU) was diagnosed in eight patients: all women. Results: The most pronounced differences between experimental group participants and controls are seen in the flowmotion (FM), neurogenic oscillation (NEURO), and normoxia oscillatory index (NOI) parameters characterizing microcirculation oscillations. In alopecia, microcirculation oscillations characterized by the FM and NEURO parameters are significantly decreased. Conclusions: This observation may suggest that neuroinflammation is an important factor responsible for alopecia pathogenesis. The women with alopecia areata have dysfunctional microcirculatory function. FMSF could serve as a useful tool for monitoring patients with alopecia.

Keratin 6A promotes skin inflammation through JAK1-STAT3 activation in keratinocytes

BACKGROUND

Skin barrier dysfunction and immune activation are hallmarks of inflammatory skin diseases such as rosacea and psoriasis, suggesting shared pathogenic mechanisms. While barrier disruption may trigger or exacerbate skin inflammation, the precise underlying mechanisms remain unclear. Notably, epidermal barrier compromise leads to a marked increase in barrier alarmin expression. Among these, keratin 6A (KRT6A) plays a role in maintaining skin barrier integrity.

METHODS

We treated mouse skin and human keratinocytes, with and without KRT6A expression, with LL37/TNF-α and assessed the severity of inflammation. The specific mechanism by which KRT6A promotes skin inflammation was investigated using mass spectrometry and immunoprecipitation assays.

RESULTS

KRT6A expression was elevated in lesional skin from patients and mouse models of rosacea and psoriasis. In mice with LL37-induced rosacea-like and imiquimod (IMQ)-induced psoriasis-like skin inflammation, KRT6A knockdown alleviated inflammation, whereas KRT6A overexpression exacerbated inflammatory responses. Mechanistically, KRT6A activated signal transducer and activator of transcription 3 (STAT3) and enhanced proinflammatory cytokine expression in keratinocytes by reducing Janus kinase 1 (JAK1) ubiquitination. This occurred through inhibition of ring finger protein 41 (RNF41)-mediated JAK1 binding.

CONCLUSIONS

Our findings indicate that KRT6A expression increases following epidermal barrier disruption and contributes to exacerbated skin inflammation in disease conditions. Targeting KRT6A may represent a novel therapeutic approach for inflammatory skin diseases associated with epidermal dysfunction.

Efficacy and Safety of Oxymetazoline 1% Cream for the Treatment of Mild to Moderate Facial Rosacea

INTRODUCTION

Rosacea is a common skin condition that affects the physical and mental health of the patient. The objective of this study was to evaluate the efficacy and safety of oxymetazoline 1% cream, a specific α1A-adrenoceptor agonist, for the treatment of mild to moderate facial rosacea.

METHODS

In phase II of the before-after study, 15 patients with mild to moderate rosacea were enrolled and treated with oxymetazoline 1% cream twice daily for 4 weeks. The clinician's erythema assessment (CEA) and patient's self-assessment (PSA), as well as the skin biometric parameters (transepidermal water loss, sebum, stratum corneum hydration, temperature, erythema, melanin, and pH), dermal and epidermal thickness and echo-density, and capillaroscopic pattern were assessed and compared before and after treatment. p-Value < 0.05 was considered significant.

RESULTS

CEA and PSA indexes decreased significantly 2 and 4 weeks after the treatment (p-value: 0.001). The erythema index also decreased significantly in both 2 weeks (p-value: 0.001) and 4 weeks (p-value: 0.001) after the treatment. The capillaroscopic pattern of lesions showed a decrease in telangiectasia and a reddish background of skin. No side effects of treatment were experienced by any of the patients.

CONCLUSION

Oxymetazoline 1% cream was safe and effective in treating mild to moderate facial rosacea. The reduction in the skin's vascularity was also objectively confirmed.

Casticin reduces rosacea-related inflammation by inhibiting mast cell activation via Mas-related G protein-coupled receptor X2

BACKGROUND

Rosacea is a chronic inflammatory disease characterized by persistent erythema, papules, and pustules, mainly on the skin of the face. Rosacea is difficult to treat; therefore, identifying new treatments is crucial. Mas-related G protein-coupled receptor X2 (MRGPRX2)-mediated mast cell (MC) activation is essential in the pathogenesis of rosacea. Casticin has been shown to exert anti-inflammatory effects; however, it remains unclear whether it can inhibit MRGPRX2 in treating rosacea. This study determined the therapeutic efficacy of casticin against rosacea by inhibiting MRGPRX2-mediated MC activation.

METHODS

A mouse model of LL37-induced rosacea-like dermatitis was employed. The pathological changes were evaluated using hematoxylin and eosin (H&E) staining, and MCs and CD4+ T cells were observed. Inflammatory mediators were analyzed using ELISA. Mouse skin lesions were collected for transcriptomic sequencing. We used an MRGPRX2-mediated MC degranulation model to evaluate the inhibitory effects of casticin in vitro. Molecular docking analysis, molecular dynamics simulations, and surface plasmon resonance evaluated the binding between casticin and MRGPRX2.

RESULTS

Casticin attenuated the LL37-induced inflammatory phenotype and reactions in rosacea-like dermatitis. RNA-seq data showed that casticin inhibited MC activation in a mouse model of rosacea. Furthermore, casticin significantly reduced CD4 + T-cell infiltration. Moreover, casticin inhibited MC activation as an MRGPRX2 antagonist in vitro and in vivo by influencing the NF-κB signaling pathway.

CONCLUSION

Our study demonstrated that casticin exhibits therapeutic efficacy against rosacea by inhibiting MC activation via MRGPRX2.

Insights into Liposomal and Gel-Based Formulations for Dermatological Treatments

Dermatological diseases pose a significant challenge due to their chronic nature, complex pathophysiology, and the need for effective, patient-friendly treatments. Recent advancements in liposomal and gel-based formulations have played a crucial role in improving drug delivery, therapeutic efficacy, and patient compliance. Liposomal formulations have garnered considerable attention in dermatology due to their ability to encapsulate both hydrophilic and lipophilic compounds, enabling controlled drug release and enhanced skin penetration. However, challenges such as formulation complexity, stability issues, and regulatory constraints remain. Similarly, gel-based formulations are widely used due to their ease of application, biocompatibility, and ability to retain active ingredients. However, they also face limitations, including restricted penetration depth, susceptibility to microbial contamination, and challenges in achieving sustained drug release. The integration of liposomal and gel-based technologies offers a promising strategy to overcome current challenges and optimize dermatological drug delivery. This review explores both well-established therapies and recent innovations, offering a comprehensive overview of their applications in the treatment of prevalent dermatological conditions. Ultimately, continued research is essential to refine these formulations, expanding their clinical utility and enhancing therapeutic effectiveness in dermatology.

Beyond the classic players: Mas-related G protein-coupled receptor member X2 role in pruritus and skin diseases

Chronic spontaneous urticaria (CSU), atopic dermatitis (AD), psoriasis and rosacea are highly prevalent inflammatory skin conditions which impose a significant burden on patients' quality of life. Their pathophysiology is likely multifactorial, involving genetic, immune and environmental factors. Recent advancements in the field have demonstrated the key role of mast cells (MC) in the pathophysiology of these conditions. The Mas-related G protein-coupled receptor X2 (MRGPRX2) has emerged as a promising non-IgE-mediated MC activation receptor. MRGPRX2 is predominately expressed on MC and activated by endogenous and exogenous ligands, leading to MC degranulation and release of various pro-inflammatory mediators. Mounting evidence on the presence of endogenous MRGPRX2 agonists (substance P, cortistatin-14, LL37, PAMP-12 and VIP) and its high expression among patients with CSU, AD, rosacea, psoriasis and chronic pruritus emphasizes the pathogenic role of MRGPRX2 in these conditions. Despite the currently available treatments, there remains a pressing need for novel drug targets and treatment options for these chronic inflammatory skin conditions. Here, we reviewed the pathogenic role of MRGPRX2 and its potential as a novel therapeutic target and provided an update on future research directions.

Integrative systems biology framework discovers common gene regulatory signatures in mechanistically distinct inflammatory skin diseases

More than 20% of the population across the world is affected by non-communicable inflammatory skin diseases including psoriasis, atopic dermatitis, hidradenitis suppurativa, rosacea, etc. Many of these chronic diseases are painful and debilitating with limited effective therapeutic interventions. This study aims to identify common regulatory pathways and master regulators that regulate the molecular pathogenesis of inflammatory skin diseases. We designed an integrative systems biology framework to identify the significant regulators across several diseases. Network analytics unraveled 55 high-value proteins as significant regulators in molecular pathogenesis which can serve as putative drug targets for more effective treatments. We identified IKZF1 as a shared master regulator in hidradenitis suppurativa, atopic dermatitis, and rosacea with known disease-derived molecules for developing efficacious combinatorial treatments for these diseases. The proposed framework is very modular and indicates a significant path of molecular mechanism-based drug development from complex transcriptomics data and other multi-omics data.

Plant Phenolics in the Prevention and Therapy of Acne: A Comprehensive Review

Plants are a rich source of secondary metabolites, among which phenolics are the most abundant. To date, over 8000 various polyphenolic compounds have been identified in plant species, among which phenolic acids, flavonoids, coumarins, stilbenes and lignans are the most important ones. Acne is one of the most commonly treated dermatological diseases, among which acne vulgaris and rosacea are the most frequently diagnosed. In the scientific literature, there is a lack of a detailed scientific presentation and discussion on the importance of plant phenolics in the treatment of the most common specific skin diseases, e.g., acne. Therefore, the aim of this review is to gather, present and discuss the current state of knowledge on the activity of various plant phenolics towards the prevention and treatment of acne, including in vitro, in vivo and human studies. It was revealed that because of their significant antibacterial, anti-inflammatory and antioxidant activities, phenolic compounds may be used in the treatment of various types of acne, individually as well as in combination with commonly used drugs like clindamycin and benzoyl peroxide. Among the various phenolics that have been tested, EGCG, quercetin and nobiletin seem to be the most promising ones; however, more studies, especially clinical trials, are needed to fully evaluate their efficacy in treating acne.

Rosacea in East Asian populations: Clinical manifestations and pathophysiological perspectives for accurate diagnosis

Rosacea is a chronic inflammatory disorder primarily affecting the facial skin, prominently involving the cheeks, nose, chin, forehead, and periorbital area. Cutaneous manifestations encompass persistent facial erythema, phymas, papules, pustules, telangiectasia, and flushing. The pathogenesis of rosacea is associated with various exacerbating or triggering factors, including microbial infestation, temperature fluctuations, sunlight exposure, physical exertion, emotional stress, consumption of hot beverages and spicy foods, and exposure to airborne pollen. These environmental factors interact with genetic predispositions in the development of rosacea. The roles of the lipophilic microbiome, ultraviolet radiation, nociceptive responses, and vascular alterations have been proposed as significant factors in the pathogenesis. These insights contribute to understanding the anatomical specificity of facial involvement and the progressive nature of rosacea. East Asian skin, predominantly classified as Fitzpatrick skin phototypes III to IV, is characterized by relatively diminished skin barrier function and increased sensitivity to irritants. Airborne pollen exposure may particularly act as a trigger in East Asian individuals, possibly mediated through toll-like receptors. The lack of specificity in objective clinical and histopathological findings leads to diagnostic challenges for individuals with colored skin, including East Asians, particularly when erythema is the sole objective manifestation. An alternative diagnostic scheme may thus be necessary. A diagnostic approach emphasizing vascular manifestations and nociceptive symptoms potentially holds promise for individuals with darker skin tones. More research focusing on potential variations in skin physiology across different racial groups is essential to establish more effective diagnostic schemes applicable to both dark and light skin colors.

LncRNA NEAT1 targets miR-125/ADAM9 mediated NF-κB pathway in inflammatory response of rosacea

OBJECTIVE

To investigate the role of NEAT1 targeted regulation of miR-125/ADAM9 mediated NF-κB pathway in inflammatory response in rosacea.

METHOD

HaCaT cell rosacea phenotype was induced by LL37. The connection targeted by NEAT1 and miR-125a-5p was confirmed by Double-Luciferase report analysis. qPCR was employed to assess the levels of expression for NEAT1, miR-125a-5p, and ADAM9 genes. The levels of expression for ADAM9/TLR2/NF-κB P65 pathway proteins in each batch of cells were determined by Western blotting. The levels of expression for inflammatory factors, including TNF-α, IL-1β, IL-6, and IL-18, were measured through ELISA experimentation.

RESULTS

LL37 could successfully induce HaCaT cells to exhibit rosacea phenotype. The luciferase report experiment confirmed that NEAT1 could target and bind miR-125a-5p and inhibit its expression. ADAM9 exhibited increased expression in LL37-induced HaCaT cells, showing a positive association with NEAT1 expression and inverse relationship with miR-125a-5p activation. LL37 treatment promoted the expression of ADAM9/TLR2/NF-κB P65 pathway proteins. Silencing ADAM9 can inhibit the inflammatory signaling pathway and reduce the level of TNF-α, IL-1β, IL-6, and IL-18 in HaCaT cells.

CONCLUSION

NEAT1 can suppress the production of miR-125a-5p and activate the TLR2/NF-κB inflammatory pathway mediated by ADAM9, thereby promoting the inflammatory response in rosacea.

Randomised, split-face study of a dermocosmetic cream containing Sphingobioma xenophaga extract and Neurosensine® in subjects with rosacea associated with erythema and sensitive skin

INTRODUCTION

Rosacea is a chronic inflammatory skin condition associated with erythema, inflammation and skin sensitivity.

OBJECTIVES

To assess the benefit of a dermocosmetic cream (DC cream) containing Sphingobioma xenophaga extract and soothing agent in adult females with rosacea-associated erythema and sensitive skin.

MATERIALS AND METHODS

During phase 1, DC was applied twice daily on the randomized half-face and compared to usual-skincare (USC) for 28 days. During phase 2, DC was applied on the full face twice daily for 56 days. Clinical, instrumental and skin sensitivity assessments were performed at all visits; demodex density (standardized skin surface biopsy (SSSB) method) was performed at baseline and D28, quality of life (QoL) was assessed using the stigmatization questionnaire (SQ), Rosacea Quality of Life index (ROSAQoL) and Dermatology Life Quality Index (DLQI) at baseline and D84.

RESULTS

At D28, a significant benefit of DC over USC was observed for erythema, tightness, burning and stinging (all p ≤ 0.05), erythema measured by chromameter (p < 0.01), corneometry and transepidermal water loss (p < 0.0001 and p < 0.05, respectively), skin sensitivity (p < 0.001) and significant reduction of mean demodex density (p < 0.05) on the DC side. At D84, DC significantly (all p < 0.05) improved clinical signs and symptoms on both sides of the face compared to baseline; SQ, ROSAQoL and DLQI scores improved by 40.4%, 25.0% and 55.7%, respectively compared to baseline. Tolerance was excellent.

CONCLUSION

DC significantly improved erythema, skin sensitivity, demodex count, QoL and feeling of stigmatization of subjects with rosacea and is very well tolerated.

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.

Rosacea: Pathogenesis and Therapeutic Correlates

Rosacea is a chronic inflammatory condition of which there is no cure. The pathogenesis of rosacea is likely multifactorial, involving genetic and environmental contributions. Current understanding suggests that pro-inflammatory pathways involving cathelicidins and inflammasome complexes are central to rosacea pathogenesis. Common rosacea triggers modulate these pathways in a complex manner, which may contribute to the varying severity and clinical presentations of rosacea. Established and emerging rosacea treatments may owe their efficacy to their ability to target different players in these pro-inflammatory pathways. Improving our molecular understanding of rosacea will guide the development of new therapies and the use of combination therapies.

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.

Advancements in non-invasive skin sampling: Clinical conditions characterization via the assessment of skin surface cytokine biomarkers

The skin is increasingly recognized as a biological active organ interacting with the immune system. Given that the epidermal skin layer actively releases various cytokines, non-invasive skin sampling methods could detect these cytokines, offering insights into clinical conditions. This study aims non-invasively measuring cytokine levels directly from the skin surface to characterize different inflammatory chronic disorders in the adult and elderly population: psoriasis, diabetes type 2, rosacea, chronic kidney disease (CKD) and aging. Cytokines IL-1β, IL-8 and IL-10 were sampled from healthy subjects and patients aged 18-80 using skin surface wash technique. A well with sterile phosphate-buffered saline solution was placed on the skin for 30 min, and the extracted solution was collected from the well for further cytokine levels analysis using ELISA assay. Results show distinct cytokine profiles in different pathological processes, healthy controls, affected and unaffected areas. Aging was associated with increased IL-1β, IL-8, and IL-10 levels in skin. In diabetes, IL-1β and IL-8 levels were elevated in lesional areas, while IL-10 levels were decreased in non-lesional skin. Psoriatic lesions showed elevated levels of IL-1β and IL-8. Rosacea patients had lower IL-10 levels in both lesional and non-lesional areas. CKD patients exhibited significantly lower IL-10 levels compared to healthy individuals. In conclusion, skin surface wash-derived cytokine profiles could serve as "alert biomarkers" for disease prediction, enabling early detection. Additionally, this method's cost-effectiveness allows pre-screening of molecules in clinical studies and holds potential as a tool for biomarkers and omics analysis, enhancing disorder characterization and disease management.

A Review of the Diagnostic and Therapeutic Gaps in Rosacea Management: Consensus Opinion

Rosacea is a common, chronic inflammatory disease characterized by both fluctuating and fixed heterogeneous signs such as facial erythema, papules/pustules, telangiectasia, acute vasodilation (flushing), and phymatous changes, and symptoms such as cutaneous stinging and burning. The shift to a phenotype-based approach to rosacea management has improved the consistency of recommendations across recent published guidelines. Consistent and thorough guidance for the classification, diagnosis, and management of the disease is difficult, as the mechanisms underlying the development of rosacea are still not completely understood nor universally accepted. Here, we provide a critical review of current published guidance, and gaps in the knowledge and management of rosacea. We present the recently approved microencapsulated benzoyl peroxide as an effective topical treatment option for papulopustular rosacea. Benzoyl peroxide (BPO) has been used in acne management for many years; however, many clinicians perceive treatment of rosacea with any BPO formulation to be counterintuitive because of concerns of potential skin irritation, while the lack of an accepted mechanism of action on rosacea pathophysiology means that others may be hesitant to use BPO as a treatment. Minocycline foam 1.5% is also an option for the treatment of inflammatory lesions in rosacea, with a decreased risk of systemic adverse events compared with oral minocycline.

Dendrobium polysaccharide (DOP) ameliorates the LL-37-induced rosacea by inhibiting NF-κB activation in a mouse model

BACKGROUND

Rosacea, a common chronic inflammatory skin disease worldwide, is currently incurable with complex pathogenesis. Dendrobium polysaccharide (DOP) may exert therapeutic effects on rosacea via acting on the NF-κB-related inflammatory and oxidative processes.

MATERIALS AND METHODS

In this study, an LL-37-induced rosacea-like mouse model was established. HE staining was used to assess the skin lesions, erythema severity scores, pathological symptoms, and inflammatory cell numbers of mice in each group. The inflammation level was quantitatively analyzed using enzyme-linked immunosorbent assay (ELISA) and reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR). The expression levels of TLR4 and p-NF-κB were finally detected.

RESULTS

DOP improved skin pathological symptoms of rosacea mice. DOP also alleviated the inflammation of rosacea mice. Moreover, the TLR4/NF-κB pathway was observed to be inhibited in the skin of mice after DOP application. These findings evidenced the anti-inflammatory effects of DOP on the LL-37-induced rosacea mouse model. DOP could inhibit NF-κB activation, suppress neutrophil infiltration, and reduce pro-inflammatory cytokines production, which may be the reason for DOP protecting against rosacea.

CONCLUSION

This study may propose an active candidate with great potential for rosacea drug development and lay a solid experimental foundation for promoting DOP application in rosacea therapy.

Rosacea pathogenesis and therapeutics: current treatments and a look at future targets

Rosacea is a chronic inflammatory skin condition associated with a significant health and economic burden from costs and loss of productivity due to seeking medical treatment. The disease encompasses multiple phenotypic manifestations involving a complex and multi-variate pathogenesis. Although the pathophysiology of rosacea is not completely understood, ongoing research is continually elucidating its mechanisms. In this review, current concepts of rosacea pathogenesis will be addressed which involve skin barrier and permeability dysfunction, the innate and adaptive immune systems, and the neurovascular system. More specifically, the cathelicidin pathway, transient potential receptor channels, mast cells, and the NLRP3 inflammasome pathway are various targets of current pharmacologic regimens. Future therapies may seek different mechanisms to act on current treatment targets, like the potential use of JAK/STAT inhibitors in ameliorating skin barrier dysfunction or TLR antagonists in alleviating cathelicidin mediated inflammation. Other potential treatments aim for entirely different molecular targets such as microvesicle particle mediated local and systemic inflammation. Ultimately rosacea is associated with a significant health and economic burden which warrants deeper research into its pathogenesis and resultant new treatment discovery.

MRGPRX2, drug pseudoallergies, inflammatory diseases, mechanisms and distinguishing MRGPRX2- and IgE/FcεRI-mediated events

MRGPRX2, a novel Gaq -coupled human mast cell receptor, mediates non-immune adverse reactions without the involvement of antibody priming. Constitutively expressed by human skin mast cells, MRGPRX2 modulates cell degranulation producing pseudoallergies manifesting as itch, inflammation and pain. The term pseudoallergy is defined in relation to adverse drug reactions in general and immune/non-immune-mediated reactions in particular. A list of drugs with MRGPRX2 activity is presented, including a detailed examination of three important and widely used approved therapies: neuromuscular blockers, quinolones and opioids. For the clinician, the significance of MRGPRX2 is considered as an aid in distinguishing and ultimately identifying specific immune and non-immune inflammatory reactions. Anaphylactoid/anaphylactic reactions, neurogenic inflammation and inflammatory diseases with a clear or strongly suspected association with MRGPRX2 activation are examined. Inflammatory diseases include chronic urticaria, rosacea, atopic dermatitis, allergic contact dermatitis, mastocytosis, allergic asthma, ulcerative colitis and rheumatoid arthritis. MRGPRX2- and allergic IgE/FcεRI-mediated reactions may be clinically similar. Importantly, the usual testing procedures do not distinguish the two mechanisms. Currently, identification of MRGPRX2 activation and diagnosis of pseudoallergic reactions is generally viewed as a process of exclusion once other non-immune and immune processes, particularly IgE/FcεRI-mediated degranulation of mast cells, are ruled out. This does not take into account that MRGPRX2 signals via β-arrestin, which can be utilized to detect MRGPRX2 activation by employing MRGPRX2 transfected cells to assess MRGPRX2 activation via two pathways, the G-protein-independent β-arrestin pathway and the G-protein-dependent Ca2+ pathway. Testing procedures, interpretations for distinguishing mechanisms, patient diagnosis, agonist identification and drug safety evaluations are addressed.

Exploring the Association between Gut Microbiota and Inflammatory Skin Diseases: A Two-Sample Mendelian Randomization Analysis

Emerging research underscores the substantial link between gut flora and various inflammatory skin diseases. We hypothesize that there exists a complex gut-skin axis, possibly affecting the progression of conditions such as eczema, acne, psoriasis, and rosacea. However, the precise nature of the causal connection between gut flora and skin diseases remains unestablished. In this study, we started by compiling summary data from genome-wide association studies (GWAS) featuring 211 unique gut microbiota and four types of skin conditions. We scrutinized these data across different taxonomic strata. Subsequently, we leveraged Mendelian randomization (MR) to ascertain if there is a causal link between gut microbiota and these skin conditions. We also performed a bidirectional MR analysis to identify the causality's direction. By utilizing Mendelian randomization, we identified 26 causal connections between the gut microbiome and four recognized inflammatory skin conditions, including 9 positive and 17 negative causal directions. Additional sensitivity analyses of these results revealed no evidence of pleiotropy or heterogeneity. Our MR analysis suggests a causal connection between gut microbiota and skin diseases, potentially providing groundbreaking perspectives for future mechanistic and clinical studies on microbiota-affected skin conditions.

Rosacea Topical Treatment and Care: From Traditional to New Drug Delivery Systems

Rosacea is a multifactorial chronic inflammatory dermatosis characterized by flushing, nontransient erythema, papules and pustules, telangiectasia, and phymatous alterations accompanied by itching, burning, or stinging, the pathophysiology of which is not yet fully understood. Conventional topical treatments usually show limited efficacy due to the physical barrier property of the skin that hinders skin penetration of the active ingredients, thereby hampering proper drug skin delivery and the respective therapeutic or cosmetic effects. New advances regarding the physiopathological understanding of the disease and the underlying mechanisms suggest the potential of new active ingredients as promising therapeutic and cosmetic approaches to this dermatosis. Additionally, the development of new drug delivery systems for skin delivery, particularly the potential of nanoparticles for the topical treatment and care of rosacea, has been described. Emphasis has been placed on their reduced nanometric size, which contributes to a significant improvement in the attainment of targeted skin drug delivery. In addition to the exposition of the known pathophysiology, epidemiology, diagnosis, and preventive measures, this Review covers the topical approaches used in the control of rosacea, including skin care, cosmetics, and topical therapies, as well as the future perspectives on these strategies.

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.

The Relationship Between Rosacea and Inflammatory Bowel Disease: A Systematic Review and Meta-analysis

INTRODUCTION

Rosacea and inflammatory bowel disease (IBD) are chronic inflammatory disorders of the skin and the gut, which are interfaces between the environment and the human body. Although growing evidence has implicated a possible link between rosacea and IBD, it remains unclear whether IBD increases the risk of rosacea and vice versa. Therefore, we investigated the association between rosacea and IBD in this study.

METHODS

We performed a systematic review and meta-analysis according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines.

RESULTS

Eight eligible studies were included in this meta-analysis. Overall, the prevalence of rosacea was higher in the IBD group than in the control group, with a pooled odds ratio (OR) of 1.86 (95% confidence interval [CI](1), 1.52-2.26). Both the Crohn's disease and the ulcerative colitis groups had higher prevalences of rosacea than the control group, with ORs of 1.74 (95% CI 1.34-2.28) and 2.00 (95% CI 1.63-2.45), respectively. Compared with those in the control group, the risks of IBD, Crohn's disease, and ulcerative colitis were significantly higher in the rosacea group, with incidence rate ratios of 1.37 (95% CI 1.22-1.53), 1.60 (95% CI 1.33-1.92), and 1.26 (95% CI 1.09-1.45), respectively.

CONCLUSION

Our meta-analysis suggests that IBD is bidirectionally associated with rosacea. Future interdisciplinary studies are needed to better understand the mechanism of interaction between rosacea and IBD .

New Insights into the Mutual Promotion of Rosacea, Anxiety, and Depression from Neuroendocrine Immune Aspects

Rosacea is a common chronic inflammatory skin disease with a complex etiology and undefined pathogenesis, and there is still a lack of targeted clinical treatment. Patients with rosacea are at a higher risk of anxiety and depression compared to the healthy population. Compared to skin conditions such as acne and psoriasis, rosacea has been much less studied in relation to multiple-etiology psychiatric disorders such as anxiety and depression. In contrast to the mainstream belief that the causal association between rosacea and psychiatric disorders is that rosacea increases the psychological burden of patients and thus triggers psychiatric disorders simply by altering their facial appearance, this review outlines the possible common mechanisms between rosacea and anxiety and depression disorders, starting from the pathophysiological mechanisms of transient receptor potential family cation channels, HPA axis, and Th1/Th17 cell polarization. It envisages the possibility of the neuroendocrine-immune interplay between rosacea and anxiety and depression, and new ideas on the complex causal relationship between rosacea and psychiatric disorders, offering more orientations to open up new therapeutic approaches for rosacea.

The Role of Mast Cells in the Induction and Maintenance of Inflammation in Selected Skin Diseases

Under physiological conditions, skin mast cells play an important role as guardians that quickly react to stimuli that disturb homeostasis. These cells efficiently support, fight infection, and heal the injured tissue. The substances secreted by mast cells allow for communication inside the body, including the immune, nervous, and blood systems. Pathologically non-cancerous mast cells participate in allergic processes but also may promote the development of autoinflammatory or neoplastic disease. In this article, we review the current literature regarding the role of mast cells in autoinflammatory, allergic, neoplastic skin disease, as well as the importance of these cells in systemic diseases with a pronounced course with skin symptoms.

CGRP physiology, pharmacology, and therapeutic targets: migraine and beyond

Calcitonin gene-related peptide (CGRP) is a neuropeptide with diverse physiological functions. Its two isoforms (α and β) are widely expressed throughout the body in sensory neurons as well as in other cell types, such as motor neurons and neuroendocrine cells. CGRP acts via at least two G protein-coupled receptors that form unusual complexes with receptor activity-modifying proteins. These are the CGRP receptor and the AMY1 receptor; in rodents, additional receptors come into play. Although CGRP is known to produce many effects, the precise molecular identity of the receptor(s) that mediates CGRP effects is seldom clear. Despite the many enigmas still in CGRP biology, therapeutics that target the CGRP axis to treat or prevent migraine are a bench-to-bedside success story. This review provides a contextual background on the regulation and sites of CGRP expression and CGRP receptor pharmacology. The physiological actions of CGRP in the nervous system are discussed, along with updates on CGRP actions in the cardiovascular, pulmonary, gastrointestinal, immune, hematopoietic, and reproductive systems and metabolic effects of CGRP in muscle and adipose tissues. We cover how CGRP in these systems is associated with disease states, most notably migraine. In this context, we discuss how CGRP actions in both the peripheral and central nervous systems provide a basis for therapeutic targeting of CGRP in migraine. Finally, we highlight potentially fertile ground for the development of additional therapeutics and combinatorial strategies that could be designed to modulate CGRP signaling for migraine and other diseases.

Molecular Mechanisms of Neurogenic Inflammation of the Skin

The skin, including the hypodermis, is the largest body organ and is in constant contact with the environment. Neurogenic inflammation is the result of the activity of nerve endings and mediators (neuropeptides secreted by nerve endings in the development of the inflammatory reaction in the skin), as well as interactions with other cells such as keratinocytes, Langerhans cells, endothelial cells and mast cells. The activation of TRPV-ion channels results in an increase in calcitonin gene-related peptide (CGRP) and substance P, induces the release of other pro-inflammatory mediators and contributes to the maintenance of cutaneous neurogenic inflammation (CNI) in diseases such as psoriasis, atopic dermatitis, prurigo and rosacea. Immune cells present in the skin (mononuclear cells, dendritic cells and mast cells) also express TRPV1, and their activation directly affects their function. The activation of TRPV1 channels mediates communication between sensory nerve endings and skin immune cells, increasing the release of inflammatory mediators (cytokines and neuropeptides). Understanding the molecular mechanisms underlying the generation, activation and modulation of neuropeptide and neurotransmitter receptors in cutaneous cells can aid in the development of effective treatments for inflammatory skin disorders.

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.

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.

Interleukin-18 and IL-18BP in inflammatory dermatological diseases

Interleukin (IL)-18, an interferon-γ inducer, belongs to the IL-1 family of pleiotropic pro-inflammatory factors, and IL-18 binding protein (IL-18BP) is a native antagonist of IL-18 in vivo, regulating its activity. Moreover, IL-18 exerts an influential function in host innate and adaptive immunity, and IL-18BP has elevated levels of interferon-γ in diverse cells, suggesting that IL-18BP is a negative feedback inhibitor of IL-18-mediated immunity. Similar to IL-1β, the IL-18 cytokine is produced as an indolent precursor that requires further processing into an active cytokine by caspase-1 and mediating downstream signaling pathways through MyD88. IL-18 has been implicated to play a role in psoriasis, atopic dermatitis, rosacea, and bullous pemphigoid in human inflammatory skin diseases. Currently, IL-18BP is less explored in treating inflammatory skin diseases, while IL-18BP is being tested in clinical trials for other diseases. Thereby, IL-18BP is a prospective therapeutic target.

A Randomized, Controlled Clinical Trial of a Dermocosmetic Containing Vichy Volcanic Mineralizing Water and Probiotic Fractions in Subjects with Rosacea Associated with Erythema and Sensitive Skin and Wearing Protective Masks

Purpose

Rosacea is a common facial dermatosis, with flares induced by exposome factors. M89PF containing Vichy mineralizing water, probiotic fractions, hyaluronic acid, niacinamide and tocopherol repairs the skin barrier and reinforces skin defences against exposome factors. This study assessed the benefit of M89PF in subjects with rosacea associated with erythema and sensitive skin during the Covid-19 pandemic using protective face masks.

Methods

M89PF was compared to usual skin care in a randomized, split-face study, for 30 days in subjects with rosacea associated with erythema and sensitive skin. Clinical evaluations included erythema, desquamation, skin tightness, dryness, burning sensation, itching, stinging, stinging test, and local tolerability. Instrument evaluations included erythema, skin hydration and TEWL. Subject satisfaction was also assessed.

Results

Erythema significantly improved with M89PF at both time points (p<0.01 at D15, and p<0.001 at D30). Skin sensitivity assessed by the skin stinging test improved significantly (p<0.01) with M89PF at D30, compared to baseline and usual skin care. Skin erythema, tightness, dryness, hydration and TEWL significantly improved (p≤0.05) with M89PF at D15 and D30, versus baseline and the untreated side. Subjects were highly satisfied with M89PF at D15 and D30. Tolerance was very good in all subjects.

Conclusion

In subjects with rosacea, M89PF significantly reduces erythema, skin tightness, dryness and TEWL, and improves skin hydration and skin sensitivity, even when using protective masks. M89PF is well tolerated and received high satisfaction ratings.

ClinicalTrialsgov No

NCT05562661.

Treatment strategies, including antibiotics, to target the immune component of rosacea

INTRODUCTION

Recent advances in the understanding of the pathophysiology of rosacea have led to increased focus on the disease's immunologic etiology and to the development of immunologically based treatments. With many patients suffering from incomplete control, addressing the immune components of the disease process may provide a more effective treatment option for rosacea patients that may improve quality of life.

AREAS COVERED

This review will provide a brief overview of the pathophysiology of rosacea, as well as specific immunologic contributions to the disease state. Current standard-of-care treatments will be described, including anti-parasitic, anti-inflammatory agents, and antibiotics. Emphasis will be placed on treatments that target the immune components of the disease process.

EXPERT OPINION

Rosacea remains a difficult dermatologic disease to treat, partially due to an incomplete understanding of the disease pathophysiology. The immune pathophysiology of rosacea, particularly the key role of inflammation, has been clarified over the past decade. Identification of specific molecules, including cytokines and nuclear transcription factors, may allow for the development of targeted rosacea-specific biologic and topical treatments. However, medication nonadherence is a limiting factor to achieving symptomatic control among rosacea patients. Focusing on the development of oral or injectable forms of therapy may circumvent poor adherence.

Assessment of hearing loss in patients with rosacea

OBJECTIVES/AIMS

Rosacea is not only a skin condition but a systemic inflammatory disease that includes chronic inflammation, vascular alterations, and autoimmunity in pathogenesis. We aimed to evaluate the presence of a sensorineural hearing loss in the patients with rosacea in comparison with the healthy control group and, also to compare the audiometric results according to the severity of disease among the patient group.

METHODS

Fifty-three patients with erythematelangiectatic or papulopustular type of rosacea and 105 age- and sex-matched healthy controls were included. Each participant had audiometric measurements after a complete ear-nose-throat examination by the same otorhinolaryngologist.

RESULTS

The results of air and bone conduction thresholds showed statistically significant differences in particularly high frequencies between the groups in both the right and left ear (for all p < 0.05), but there was no correlation between audiometric measurements and the severity or the type of rosacea (p > 0.05).

CONCLUSIONS

Regardless of disease severity or type, rosacea patients are likely to have sensorineural hearing loss, and it is important to refer these patients in the early period.

Diabetic Patients With Rosacea Increase the Risks of Diabetic Macular Edema, Dry Eye Disease, Glaucoma, and Cataract

PURPOSE

Inflammation plays a role in diabetic eye diseases, but the association between rosacea and eye diseases in patients with diabetes remains unknown.

DESIGN

This retrospective cohort study used claims data from the National Health Insurance Research Database in Taiwan to investigate the association between rosacea and eye diseases in patients with diabetes.

MATERIALS AND METHODS

Taiwanese patients diagnosed as having diabetes mellitus between January 1, 1997, and December 31, 2013, and using any hypoglycemic agents were included and divided into rosacea and nonrosacea groups. After applying 1:20 sex and age matching and exclusion criteria, 1:4 propensity score matching (PSM) was conducted to balance the covariate distribution between the groups. The risk of time-to-event outcome between rosacea and nonrosacea groups in the PSM cohort was compared using the Fine and Gray subdistribution hazard model.

RESULTS

A total of 4096 patients with rosacea and 16,384 patients without rosacea were included in the analysis. During a mean follow-up period of 5 years, diabetic patients with rosacea had significantly higher risks of diabetic macular edema [subdistribution hazard ratio (SHR): 1.31, 95% confidence interval (CI): 1.05-1.63], glaucoma with medical treatment (SHR: 1.11, 95% CI: 1.01-1.21), dry eye disease (SHR: 1.55, 95% CI: 1.38-1.75), and cataract surgery (SHR: 1.13, 95% CI: 1.02-1.25) compared with diabetic patients without rosacea. A cumulative incidence analysis performed up to 14 years after the index date revealed that the risks of developing ocular diseases consistently increased over time. No significant differences in diabetic retinopathy, age-related macular degeneration, retinal vascular occlusion, ischemic optic neuropathy, optic neuritis, uveitis, or retinal detachment were identified according to rosacea diagnosis. However, we observed significant associations between rosacea and psoriasis, irritable bowel syndrome, anxiety, and major depressive disorder among patients with diabetes.

CONCLUSIONS

Rosacea is associated with diabetic macular edema, glaucoma, dry eye disease, and cataract development in diabetic patients, as well as increased risks of psoriasis, irritable bowel syndrome, anxiety, and depression in diabetic patients.

Association between frontal fibrosing Alopecia and Rosacea: Results from clinical observational studies and gene expression profiles

Background

In recent years, frontal fibrosing alopecia (FFA), a type of scarring alopecia, has attracted increasing attention. Several studies have reported the frequent occurrence of rosacea in FFA; however, the association between FFA and rosacea and the underlying pathogenesis have not been thoroughly clarified. Thus, this study aimed to quantify these relationships and investigate their shared molecular mechanisms.

Methods

We evaluated the association between FFA and rosacea by analyzing clinical data from nine observational studies. We then analyzed the gene expression profiles of FFA and rosacea. First, differential expression analysis and weighted gene co-expression network analysis were used to identify the common differentially expressed genes (DEGs). Later, we conducted a functional enrichment analysis and protein-protein interaction network and used seven algorithms to identify hub genes. Then, we performed a correlation analysis between the hub genes and the gene set variation analysis scores of common pathways in the gene set enrichment analysis (GSEA). The results were validated using different datasets. Finally, transcription factors were predicted and verified, and CIBERSORT and single-sample GSEA were used to estimate the infiltrating immune cells.

Results

Patients with FFA had significantly higher odds for rosacea (pooled odds ratio [OR], 2.46; 95% confidence interval [CI], 1.78–3.40), and the pooled prevalence of rosacea in patients with FFA was 23% (95% CI, 14–23%). Furthermore, we identified 115 co-DEGs and 13 hub genes (CCR5, CCL19, CD2, CD38, CD83, CXCL8, CXCL9, CXCL10, CXCL11, CXCR4, IRF1, IRF8, and PTPRC). Seven pathways showed a high correlation with these hub genes. In addition, one TF, STAT1, was highly expressed in both diseases, and the results of the immune infiltration analysis indicated the importance of M1 macrophages and effector memory CD8+ T cells.

Conclusion

This study contributes to the understanding of the relationship between FFA and rosacea, and based on the hub genes, we reveal the potential pathologies shared by the two diseases. This finding provides new insights of underlying molecular mechanisms and it may inspire future research on this comorbidity.

S2k guideline: Rosacea

This updated and upgraded S2k guideline deals with the diagnosis and treatment of rosacea, which is a common, chronic inflammatory skin disease mostly affecting the face. Initially, rosacea is characterized by recurrent erythema, telangiectasia and flushing. Later, the inflammatory component predominates, with persistent erythema with follicular papules, papulopustules and pustules. The development of phyma, which usually occurs on the acral localizations, is the most severe manifestation. For the treatment of rosacea, the interdisciplinary guideline committee, with representatives of the German Dermatological Society (DDG), the Professional Association of German Dermatologists (BVDD), the German Opthalmological Society (DOG), the Society for Dermopharmacy (GD), the Swiss Society for Dermatology and Venereology (SGDV) and the German Rosacea Aid e. V., recommends the avoidance of trigger factors and topical applications of metronidazole, azelaic acid or ivermectin. For symptomatic treatment of persistent centrofacial erythema, the topical vasoconstrictors brimonidine or oxymetazoline can also be used. Systemic therapy is recommended for therapy-resistant and severe forms of rosacea papulopustulosa. The drug of choice is low-dose doxycycline. Alternatively, low-dose isotretinoin can be recommended. Ocular rosacea should be treated with lid margin hygiene. For topical treatment, ciclosporin eye drops, azithromycin, ivermectin or metronidazole are suggested.

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.

A dermocosmetic formulation containing Vichy volcanic mineralizing water, Vitreoscilla filiformis extract, niacinamide, hyaluronic acid, and vitamin E regenerates and repairs acutely stressed skin

The exposome has an impact on skin from life-long exposure. Acute short-term exposure to exposome stressors can also alter skin functions such as skin physical barrier and immune defenses, leading to skin dryness, sensitivity, flares of inflammatory skin conditions, or viral reactivations. Probiotics are defined as live microorganisms, which, when administered in adequate amounts, confer a health benefit on the host. An extract produced by lysing Vitreoscilla filiformis (VfeV) cultured in Vichy volcanic mineralizing water (VVMW) has properties of probiotic fractions. In this review, we present in vivo and ex vivo studies with a dermocosmetic formulation containing 80% VVMW, 5% VfeV, 4% niacinamide (vitamin B3), 0.4% hyaluronic acid, and 0.2% vitamin E (M89PF) to evaluate the clinical efficacy in preventing and repairing stressed skin. Skin barrier benefits of M89PF were shown in studies after the skin was exposed to sudden thermal changes, after skin irritation by tape stripping, and in sleep-deprived women. M89PF significantly accelerated skin renewal compared to untreated skin. Skin antioxidant defense activity of M89PF was shown after exposure to stress from UVA plus cigarette smoke aggression. Skin microbiome recovery after acute stress from a harsh cleanser was significantly better in M89PF-treated skin compared to bare skin. Clinical benefits of M89PF on correcting clinical signs of stressed skin were shown in both Caucasian and Asian women exposed to a stressful lifestyle and various external (pollution, tobacco smoking, solar radiation) and internal (poor sleep, stressful work, unbalanced diet, and alcohol consumption) exposome factors. M89PF also showed depigmenting properties on dark spots in Asian women. Further clinical studies are now warranted to evaluate the efficacy of M89PF as adjuvant care to prevent and repair skin barrier disruption and reinforce skin defenses in skin exposed to acute stresses.

Topical Brimonidine Delays Ultraviolet Radiation-Induced Squamous Cell Carcinoma in Hairless Mice

We investigated whether topical brimonidine delayed or enhanced the development of squamous cell carcinoma (SCC) when ultraviolet radiation (UVR) was applied to a well-established murine model. Hairless female mice (n = 125) were randomized into five groups and treated as follows: 1% brimonidine cream before UVR (Group 1), 0.33% brimonidine gel before UVR (Group 2), 1% brimonidine cream after UVR (Group 3), UVR only (control; Group 4) and 1% brimonidine cream only (control; Group 5). For each animal, the first four tumors were recorded and followed until three tumors reached 4 mm or one tumor reached 12 mm in diameter. All animal experiments continued for up to 365 days or until death. Application of 1% brimonidine cream before UVR delayed tumor development relative to control mice treated with UVR alone (P = 0.000006). However, when 0.33% brimonidine gel was applied before UVR (P = 0.313) or 1% brimonidine cream was applied after UVR (P = 0.252), there was no significant delay in tumor development relative to control mice treated with UVR alone. The development of the second and third tumors followed a similar pattern. Topical 1% brimonidine cream applied before UVR exposure delayed SCC development in hairless mice. In contrast, when brimonidine was applied after UVR there was no significant delay in tumor development. These results suggest that the 1% brimonidine cream probably absorbed the UVR, and therefore, a delay in tumor formation was only seen when brimonidine was applied before irradiation. However, there can be multiple reasons for this delay in photocarcinogenesis.

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.

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.

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.

Recent advances on endogenous gasotransmitters in inflammatory dermatological disorders

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Endogenous gasotransmitters nitric oxide (NO), carbon monoxide (CO), hydrogen sulfide (H₂S), and potential candidates sulfur dioxide (SO₂), methane (CH₄), hydrogen gas (H₂), ammonia (NH₃) and carbon dioxide (CO₂), are generated within the human body.

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Endogenous and potential gasotransmitters regulate inflammation, vasodilation, and oxidation in inflammatory dermatological disorders.

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Endogenous and potential gasotransmitters play potential roles in psoriasis, atopic dermatitis, acne, and chronic skin ulcers.

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Further research should explore the function of these gases and gas donors and inhibitors in inflammatory dermatological disorders.

Background

Endogenous gasotransmitters are small gaseous mediators that can be generated endogenously by mammalian organisms. The dysregulation of the gasotransmitter system is associated with numerous disorders ranging from inflammatory diseases to cancers. However, the relevance of these endogenous gasotransmitters, prodrug donors and inhibitors in inflammatory dermatological disorders has not yet been thoroughly reviewed and discussed.

Aim of review

This review discusses the recent progress and will provide perspectives on endogenous gasotransmitters in the context of inflammatory dermatological disorders.

Key scientific concepts of review

Endogenous gasotransmitters nitric oxide (NO), carbon monoxide (CO) and hydrogen sulfide (H₂S) are signaling molecules that regulate several physiological and pathological processes. In addition, sulfur dioxide (SO₂), methane (CH₄), hydrogen gas (H₂), ammonia (NH₃), and carbon dioxide (CO₂) can also be generated endogenously and may take part in physiological and pathological processes. These signaling molecules regulate inflammation, vasodilation, and oxidative stress, offering therapeutic potential and attracting interest in the field of inflammatory dermatological disorders including psoriasis, atopic dermatitis, acne, rosacea, and chronic skin ulcers. The development of effective gas donors and inhibitors is a promising alternative to treat inflammatory dermatological disorders with controllable and precise delivery in the future.

Relationship between rosacea and chronic obstructive pulmonary disease: Rosacea and comorbidities

BACKGROUND

Rosacea is a chronic inflammatory skin disease that has been reported to be associated with many systemic disorders including respiratory diseases.

AIMS

This study aims to investigate respiratory function in patients with rosacea.

PATIENTS/METHODS

Patients with rosacea and age- and gender-matched healthy volunteers were included in this cross-sectional study. Spirometric pulmonary function tests including the percentage of forced vital capacity (FVC%), percentage of forced expiratory volume in one second (FEV 1%), forced expiratory flow at 25-75% of FVC (FEF 25-75%), and FEV 1/FVC ratio was assessed in both patient and controls. The potential relationship between rosacea severity and pulmonary functions was assessed.

RESULTS

A total of 120 patients with rosacea and 120 healthy controls were enrolled in the study. Compared to the controls, FEV 1%, FEV 1/FVC%, and FEF 25-75% values were significantly lower in patients with rosacea. Lower FEV 1/FVC% values were found to be associated with disease severity. FEV 1%, FEV 1/FVC%, and FEF 25-75% values were found to be more useful in differentiating the patients from healthy subjects.

CONCLUSIONS

This study showed that patients with rosacea may have abnormal respiratory function compared to healthy subjects. Besides, disease severity was associated with worse respiratory functions. We believe that patients with rosacea, particularly those with additional risk factors, should be screened for respiratory disorders.

A randomized, controlled, split-face study of topical timolol maleate 0.5% eye drops for the treatment of erythematotelangiectatic rosacea

BACKGROUND

Centrofacial erythema associated with telangiectasis is the most common presentation of rosacea, known as erythematotelangiectatic rosacea (ETR). However, successful management of these symptoms remains challenging.

AIM

The purpose of this study was to evaluate the efficacy and safety of topical timolol maleate eye drops 0.5% for ETR.

METHODS

In this randomized, single-center, single-blind, placebo-controlled split-face study, 16 patients with mild-to-moderate ETR who presented at West China Hospital between January 2019 to September 2020 were randomized to receive either topical timolol maleate eye drops 0.5% to one side of their face daily for 28 days and normal saline to the other side of the face. Patients were assessed with both the Clinician Erythema Assessment (CEA) and Patient Self-Assessment (PSA) at the 28-day follow-up appointment. Subjective assessment was performed by asking participants to grade their sensation of warmth and burning.

RESULTS

The sides treated with timolol demonstrated a significant improvement in both the CEA and PSA at the 28-day assessment. Patients reported a significant difference in warmth and burning sensations. The only adverse reaction was worsened redness on both sides of the face at Day 1 in one patient.

CONCLUSIONS

In this small study, the application of topical timolol maleate was safe and effective for the treatment of ETR.

Antimicrobial peptides and proteins: Interaction with the skin microbiota

The cutaneous microbiota comprises all living skin microorganisms. There is increasing evidence that the microbiota plays a crucial role in skin homeostasis. Accordingly, a dysbiosis of the microbiota may trigger cutaneous inflammation. The need for a balanced microbiota requires specific regulatory mechanisms that control and shape the microbiota. In this review, we highlight the present knowledge suggesting that antimicrobial peptides (AMPs) may exert a substantial influence on the microbiota by controlling their growth. This is supported by own data showing the differential influence of principal skin-derived AMPs on commensal staphylococci. Vice versa, we also illuminate how the cutaneous microbiota interacts with skin-derived AMPs by modulating AMP expression and how microbiota members protect themselves from the antimicrobial activity of AMPs. Taken together, the current picture suggests that a fine-tuned and well-balanced AMP-microbiota interplay on the skin surface may be crucial for skin health.

A Novel Mechanism of Carvedilol Efficacy for Rosacea Treatment: Toll-Like Receptor 2 Inhibition in Macrophages

Background

Rosacea, a chronic inflammatory skin disorder etiologically associated with immune cells and the antibacterial peptide cathelicidin LL-37, can be effectively treated by oral carvedilol administration.

Objective

To investigate the molecular mechanisms underlying carvedilol efficacy in rosacea treatment.

Methods

Skin samples of patients with rosacea were subjected to histopathological (hematoxylin and eosin) and immunohistochemical (CD68, Toll-like receptor 2 (TLR2), kallikrein 5, cathelicidin, TNF-α, and IL-1β) evaluation. An in vivo murine rosacea-like inflammation model was established by LL-37 intradermal injection with or without carvedilol gavage-based pretreatment. Erythema proportion (Image J) and skin redness (L*a*b colorimetry) were quantified. Murine skin samples underwent pathological examination for inflammatory status and immunofluorescence staining. Murine skin and lipopolysaccharide-stimulated RAW 264.7 cells with or without carvedilol pretreatment were evaluated by quantitative reverse transcription-polymerase chain reaction and western blotting. Clinical facial images of patients were obtained using the VISIA skin analysis system before, 4, and 6 months following oral carvedilol administration.

Results

Rosacea skin lesions exhibited more pronounced inflammatory cell infiltration than peripheral areas, with profound macrophage infiltration and inflammatory cytokines (TLR2, kallikrein 5, cathelicidin, TNF-α, and IL-1β). In vivo, carvedilol alleviated inflammation in LL-37 mice, down-regulating TLR2, KLK5, and cathelicidin expression. In vitro, carvedilol decreased TLR2 expression in RAW 264.7 cells, further reducing KLK5 secretion and LL-37 expression and ultimately inhibiting rosacea-like inflammatory reactions. Clinical manifestations and facial redness obviously improved during 6-month follow-up with systemic carvedilol administration.

Conclusion

Carvedilol is effective against rosacea, with inhibition of macrophage TLR2 expression as a novel anti-inflammatory mechanism.