Neurovascular aspects of skin neurogenic inflammation

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.

Elevated plasma levels of calcitonin gene-related peptide in individuals with rosacea: A cross-sectional case-control study

BACKGROUND

Understanding the role of calcitonin gene-related peptide (CGRP) in the pathogenesis of rosacea might provide new therapeutic avenues for individuals with this disease.

OBJECTIVE

To compare plasma levels of CGRP between individuals with rosacea and healthy controls.

METHODS

In this cross-sectional case-control study conducted in Copenhagen, Denmark, we collected blood samples from the antecubital vein from adults with rosacea and from healthy controls.

RESULTS

We enrolled 123 individuals with rosacea and 68 healthy controls. After adjusting for age and sex, plasma levels of CGRP were significantly higher in individuals with rosacea (mean, 95% confidence interval: 140.21 pmol/L, 128.50-151.92 pmol/L), compared with controls (110.77 pmol/L, 99.91-120.14 pmol/L, p = 0.002). Plasma levels of CGRP were not affected by age, sex, BMI, concomitant migraine, rosacea sub- or phenotype, concomitant disease or current treatment.

LIMITATIONS

Participants were not age-, sex- and BMI-matched.

CONCLUSIONS AND RELEVANCE

Elevated plasma levels of CGRP in individuals with rosacea suggest a role of CGRP in the pathogenesis of rosacea. Targeting CGRP signalling might hold therapeutic promise in people affected by this disease.

CLINICALTRIALS

GOV LISTING

NCT03872050.

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.

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.

Increased Risk of Glaucoma in Patients with Rosacea: A Nationwide Population-Based Cohort Study

Rosacea is a chronic inflammatory skin disorder associated with various ocular manifestations. However, little is known about the association between rosacea and glaucoma. This study aimed to determine the risk of glaucoma in patients with rosacea. This nationwide population-based retrospective cohort study enrolled 1056 individuals with rosacea and 10,440 age- and sex-matched controls without rosacea from the Korean National Health Insurance System (NHIS) database from 2002 to 2015. The incidence rate of glaucoma was 1215.4 per 100,000 person-years (PYs) in patients with rosacea and 741.3 per 100,000 PYs in patients without rosacea. A significantly higher cumulative incidence probability of glaucoma was observed in patients with rosacea than in non-rosacea controls (p = 0.0004). Rosacea was associated with an increased risk of developing glaucoma (adjusted hazard ratio [aHR], 1.659; 95% confidence interval [CI], 1.245-2.211) compared to those without rosacea. In subgroup analysis, increased risk of glaucoma was observed in patients with rosacea younger than 50 years (aHR, 1.943; 95% CI, 1.305-2.893), females (aHR, 1.871; 95% CI, 1.324-2.644), and patients with hypertension (aHR, 1.561; 95% CI, 1.037-2.351) compared to those without rosacea. Rosacea is associated with an increased risk of developing glaucoma. Proper screening for glaucoma should be conducted in rosacea patients younger than 50 years, females, and patients with hypertension to better control the disease and prevent vision loss from glaucoma.

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.

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.

TRPV1: A promising therapeutic target for skin aging and inflammatory skin diseases

TRPV1 is a non-selective channel receptor widely expressed in skin tissues, including keratinocytes, peripheral sensory nerve fibers and immune cells. It is activated by a variety of exogenous or endogenous inflammatory mediators, triggering neuropeptide release and neurogenic inflammatory response. Previous studies have shown that TRPV1 is closely related to the occurrence and/or development of skin aging and various chronic inflammatory skin diseases, such as psoriasis, atopic dermatitis, rosacea, herpes zoster, allergic contact dermatitis and prurigo nodularis. This review summarizes the structure of the TRPV1 channel and discusses the expression of TRPV1 in the skin as well as its role of TRPV1 in skin aging and inflammatory skin diseases.

Combined therapy of 5-aminolevulinic acid photodynamic therapy and intense pulsed light for rosacea

Rosacea is difficult to treat. Therefore, new alternative modalities are necessary to demonstrate. The present study was conducted to assess the efficacy and safety of the combined therapy of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) and intense pulsed light (IPL) for rosacea to provide a new treatment option for rosacea. The study was conducted from November 2017 to April 2019 at the Department of Dermatology, The First Hospital of China Medical University. Patients aged 18-65 years and diagnosed clinically as erythematotelangiectatic (ET) or papulopustular (PP) rosacea were enrolled. Three times of ALA-PDT at 10 days interval followed by 3 times of IPL at 3-4 weeks interval were defined as 1 session and applied to the whole face of each patient. ALA-PDT: 5% ALA, red light (fluency dose 60-100 mW/cm2, 20 min); IPL: 560/590/640 nm, double/triple-pulse mode, pulse width 3.0 to 4.5 ms, delay time 30-40 ms, energy fluency 14-17 J/cm2. Ten patients were enrolled in the study. Among them, 4 patients received only 1 session, while 6 patients received 2 sessions. After all treatments, 50% of patients achieved 75-100% improvement, and 30% achieved 50-75% improvement. Forty percent of patients were graded very satisfaction and 30% graded moderate satisfaction. All noninvasive measurements showed no significant differences among all time points (p > 0.05). The side effects were pain, burning sensation, itching, erythema, desquamation, slight edema, slight exudation, and hyperpigmentation. All of which were tolerable and recovered in a few days. The combined therapy of ALA-PDT and IPL showed an effective option for rosacea with a safety profile.

hMSC exosomes as a novel treatment for female sensitive skin: An in vivo study

Background: Recent studies have reported that the incidence of sensitive skin is increasing. Skin sensitivity and skin barrier functions were related to many skin diseases including atopic dermatitis, psoriasis, rosacea, and so on. Mesenchymal stem cell (MSC)-derived exosomes (hMSC) might be considered as a new effective therapeutic scheme.

Aims: This study aims to investigate the safety and efficacy of hMSC exosomes as a novel topical treatment for sensitive skin.

Patients/Methods: Exosomes were extracted from primary hMSC via ultracentrifugation method. The morphology of hMSC exosomes was studied via transmission electron microscope. Expression of exosome specific surface marker was detected via Western blot. 22 subjects (female, aged 18–55) diagnosed with sensitive skin were enrolled. Follow-up was conducted before, 7-day, 14-day, and 28-day after hMSC exosomes use. Transepidermal water loss (TEWL), surface hydration, sebum secretion, and L*a*b* value were simultaneously tested at the same time point in an environment-controlled room.

Results: Under transmission electron microscopy, the extracted hMSC exosomes were circular or elliptical with intact membrane structure, and their diameters ranged mainly from 40 to 80 nm. Western blot showed that the expression of markers CD63, CD9, and Tsg101 was positive. Brownian motion based nanoparticle trajectory analysis (NTA) showed that the main peak of particle size distribution occurred around 96 nm, the average particle size was 122 nm, and the main peak accounted for 96.7%. All this conformed to the biological characteristics of exosomes standardized by the International Society for Extracellular Vesicles. In the clinical trial, scores of objective symptoms including roughness, scales, erythema, and subjective symptoms including tension, burning, or itching, were improved after 7-, 14-, and 28- day using hMSC-exosomes. TEWL, hydration, sebum, pH, and a* values were tended to return to the level of healthy skin.

Conclusion: The hMSC-exosomes, with the advantages of biocompatibility and biodegradability, could improve clinical symptoms and eruptions in sensitive skin patients, and might be as an MSC cell-free novel therapy in sensitive skin-related disease treatment.

The role of TRPV4 channels in cutaneous epithelia

Transient receptor potential vanilloid 4 (TRPV4) channels are multi-modally activated cation permeable channels that are expressed most organ tissues including the skin. TRPV4 is highly expressed in the skin and functions in skin resident cells such as epidermal keratinocytes, melanocytes, immune mast cells and macrophages, and cutaneous neurons. TRPV4 plays many crucial roles in skin homeostasis to affect an extensive range of processes such as temperature sensation, osmo-sensation, hair growth, cell apoptosis, skin barrier integrity, differentiation, nociception and itch. Since TRPV4 functions in a plenitude of pathological states, TRPV4 can become a versatile therapeutic target for diseases such as chronic pain, itch and skin cancer.

Botulinum Toxin Use for Modulating Neuroimmune Cutaneous Activity in Psoriasis

Psoriasis is a complex immune-mediated inflammatory disorder that generates enormous interest within the scientific communities worldwide, with new therapeutic targets being constantly identified and tested. Despite the numerous topical and systemic medications available for the treatment of psoriasis, alternative therapies are still needed for the optimal management of some patients who present with localized, resistant lesions. Novel insights into the contribution of cutaneous neurogenic inflammation in the pathogenesis of psoriasis have yielded exciting new potential roles of nerve-targeting treatments, namely botulinum toxin type A (BoNT-A), for the management of this disease. This paper aims to review the existing literature on knowledge regarding the potential role of BoNT-A in psoriasis treatment, with a focus on its ability to interfere with the immunopathogenetic aspects of psoriatic disease. Furthermore, in our paper, we are also including the first report of psoriatic lesions remission following local BoNT-A injections that were administered for treating upper limb spasticity, in a patient that concomitantly suffered from psoriasis and post-stroke spasticity.

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.

Asivatrep, a TRPV1 antagonist, for the topical treatment of atopic dermatitis: Phase 3, randomized, vehicle-controlled study (CAPTAIN-AD)

BACKGROUND

Asivatrep is a potent and selective antagonist of transient receptor potential vanilloid subfamily V member 1 (TRPV1), which plays an important role in itch and inflammation in atopic dermatitis (AD).

OBJECTIVE

This current study aimed to evaluate the efficacy and safety of asivatrep cream in patients with AD.

METHODS

For this phase 3 double-blind, vehicle-controlled study, patients aged ≥12 years with mild to moderate AD were enrolled and randomly assigned 2:1 to the 1.0% asivatrep or vehicle group for 8 weeks of twice-daily application (n = 240). The primary end point was the proportion of patients with an Investigator's Global Assessment score (IGA) of 0 or 1 at week 8. Standard safety assessments were conducted.

RESULTS

At week 8, significantly more patients in the asivatrep group (36.0%) than in the vehicle group (12.8%) had IGA scores of 0 or 1 (P < .001); significantly more had ≥2 points of improvement on the IGA from baseline score (20.3% vs 7.7%; P = .01). The mean percentage reduction in the Eczema Area and Severity Index (EASI) score was 44.3% for the asivatrep group and 21.4% for the vehicle group at week 8 (P < .001). Significantly more asivatrep-treated patients experienced an improvement of at least 50%, 75%, and 90% on the EASI than the vehicle group. The mean ± SD change in the pruritus visual analog scale score at week 8 was -2.3 ± 2.4 for the asivatrep group and -1.5 ± 2.4 for the vehicle group (P = .02). No significant safety issues were reported.

CONCLUSION

Asivatrep improved clinical signs and symptoms of AD and was well tolerated.

Evaluation of fibromyalgia syndrome in patients with rosacea

Objectives

This study aims to investigate the frequency of fibromyalgia syndrome (FMS) in rosacea patients and the relationship between disease disability score of FMS and quality of life score of rosacea.

Patients and methods

This cross-sectional controlled clinical trial was performed between December 2017 and December 2018. One hundred female rosacea patients (mean age 43.2±10.1; range, 21 to 65 years) and 100 age- and sex-matched control subjects (mean age 41.2±11.1; range, 22 to 68 years) with no history of skin disease and systemic diseases including diabetes, cardiovascular, renal and hepatic diseases were recruited. Dermatology Life Quality Index (DLQI) scores were calculated using a 10-item self-administered questionnaire. The diagnosis of FMS was established according to 2010 American College of Rheumatology diagnostic criteria. Fibromyalgia Impact Questionnaire (FIQ) was used to determine the clinical severity and functional disability, while Visual Analog Scale (VAS) was used to determine pain severity in the patients with FMS.

Results

The frequency of FMS in patient group was significantly higher than control group (p=0.019). The mean duration of FMS in patient group was significantly higher than control group (p=0.001). There was no significant difference in terms of the age of onset of FMS, FIQ and VAS scores between groups (p=0.53, p=0.54, p=0.07, respectively). DLQI scores were significantly correlated with FIQ scores in the patient group (r=0.43, p=0.008).

Conclusion

The frequency of FMS in rosacea patients was significantly higher than control subjects without any skin disease and there was a correlation between disability score of FMS and quality of life score of rosacea. Investigating fibromyalgia symptoms in rosacea patients may be helpful for providing patient-based therapeutic approaches where neurologically based treatments may also be beneficial for rosacea.

Multifaceted MRGPRX2: New insight into the role of mast cells in health and disease

Cutaneous mast cells (MCs) express Mas-related G protein-coupled receptor-X2 (MRGPRX2; mouse ortholog MrgprB2), which is activated by an ever-increasing number of cationic ligands. Antimicrobial host defense peptides (HDPs) generated by keratinocytes contribute to host defense likely by 2 mechanisms, one involving direct killing of microbes and the other via MC activation through MRGPRX2. However, its inappropriate activation may cause pseudoallergy and likely contribute to the pathogenesis of rosacea, atopic dermatitis, allergic contact dermatitis, urticaria, and mastocytosis. Gain- and loss-of-function missense single nucleotide polymorphisms in MRGPRX2 have been identified. The ability of certain ligands to serve as balanced or G protein-biased agonists has been defined. Small-molecule HDP mimetics that display both direct antimicrobial activity and activate MCs via MRGPRX2 have been developed. In addition, antibodies and reagents that modulate MRGPRX2 expression and signaling have been generated. In this article, we provide a comprehensive update on MrgprB2 and MRGPRX2 biology. We propose that harnessing MRGPRX2's host defense function by small-molecule HDP mimetics may provide a novel approach for the treatment of antibiotic-resistant cutaneous infections. In contrast, MRGPRX2-specific antibodies and inhibitors could be used for the modulation of allergic and inflammatory diseases that are mediated via this receptor.

Radiofrequency Irradiation Modulates TRPV1-Related Burning Sensation in Rosacea

Rosacea is a skin inflammatory condition that is accompanied by not only redness and flushing but also unseen symptoms, such as burning, stinging, and itching. TRPV1 expression in UVB-exposed skin can lead to a painful burning sensation. Upregulated TRPV1 expression helps release neuropeptides, including calcitonin gene-related peptide, pituitary adenylate cyclase-activating polypeptide, and vasoactive intestinal peptide, which can activate macrophage and inflammatory molecules. In this study, we found that radiofrequency (RF) irradiation reduced TRPV1 activation and neuropeptide expression in a UVB-exposed in vivo model and UVB- or heat-treated in an in vitro model. RF irradiation attenuated neuropeptide-induced macrophage activation and inflammatory molecule expression. Interestingly, the burning sensation in the skin of UVB-exposed mice and patients with rosacea was significantly decreased by RF irradiation. These results can provide experimental and molecular evidence on the effective use of RF irradiation for the burning sensation in patients with rosacea.

Infusion of Pituitary Adenylate Cyclase-Activating Polypeptide-38 in Patients with Rosacea Induces Flushing and Facial Edema that Can Be Attenuated by Sumatriptan

BACKGROUND

The pathogenesis of rosacea is incompletely understood. Signaling neuropeptides, including PACAP, a regulator of vasodilation and edema, are upregulated in rosacea skin. Here, we evaluated PACAP38-induced rosacea features and examined whether a 5-HT_1B/1D receptor agonist could reduce these features.

METHODS

A total of 35 patients with erythematotelangiectatic rosacea received an intravenous infusion of 10 pmol/kg/minute of PACAP38 followed by an intravenous infusion of 4 mg sumatriptan or placebo (saline) on two study days in a double-blind, randomized, placebo-controlled, and cross-over trial.

RESULTS

PACAP38 increased facial skin blood flow by 90%, dilated the superficial temporal artery by 56%, and induced prolonged flushing and facial edema. Compared with placebo, sumatriptan reduced PACAP38-induced facial skin blood flow for 50 minutes (P = 0.023), constricted the superficial temporal artery for 80 minutes (P = 0.010), and reduced duration of flushing (P = 0.001) and facial edema (P < 0.001).

CONCLUSIONS

We established a clinical experimental model of rosacea features and showed that sumatriptan was able to attenuate PACAP38-induced rosacea flushing and edema. Findings support a key role of PACAP38 in rosacea flushing pathogenesis. It remains unknown whether PACAP38 inhibition can improve rosacea.

TRIAL REGISTER

The trial was registered at ClinicalTrials.govNCT03878784 in March 2019.

Emerging topical drugs for the treatment of rosacea

Introduction: Rosacea is a common, chronic and relapsing inflammatory skin disease of the centrofacial area. Despite advancing knowledge on its pathogenesis, diagnosis, and treatment, some major unknowns still remain, including systematic evidence-based guidelines useful both for clinical assessment and therapeutic management. Topical treatment is regarded as a first-line option for mild to moderate rosacea and includes traditional and new FDA-approved prescription drugs, as well as off-label alternative topical agents.Areas covered: Since improved awareness of rosacea pathogenetic mechanisms has led to the development of new potential therapeutic agents, a search was performed on the ClinicalTrial.gov registry. The results identified several investigational topical drugs able to target one or more of the pathogenetic factors of rosacea.Expert opinion: The main unmet needs in the topical treatment of rosacea remain the management of vasomotor flushes and telangiectasias, as well as of troublesome symptoms such as burning and/or stinging. No single agent effective on all rosacea phenotypes is available so far, and preventive treatments capable of halting disease progression have not been identified yet. Finally, data on long-term efficacy and tolerability are still incomplete, especially for drugs more recently introduced in the market.

Gut-Skin Axis: Current Knowledge of the Interrelationship between Microbial Dysbiosis and Skin Conditions

The microbiome plays an important role in a wide variety of skin disorders. Not only is the skin microbiome altered, but also surprisingly many skin diseases are accompanied by an altered gut microbiome. The microbiome is a key regulator for the immune system, as it aims to maintain homeostasis by communicating with tissues and organs in a bidirectional manner. Hence, dysbiosis in the skin and/or gut microbiome is associated with an altered immune response, promoting the development of skin diseases, such as atopic dermatitis, psoriasis, acne vulgaris, dandruff, and even skin cancer. Here, we focus on the associations between the microbiome, diet, metabolites, and immune responses in skin pathologies. This review describes an exhaustive list of common skin conditions with associated dysbiosis in the skin microbiome as well as the current body of evidence on gut microbiome dysbiosis, dietary links, and their interplay with skin conditions. An enhanced understanding of the local skin and gut microbiome including the underlying mechanisms is necessary to shed light on the microbial involvement in human skin diseases and to develop new therapeutic approaches.

Neurogenic rosacea in Korea

Rosacea with severe neurological symptoms such as burning and stinging is often not treated effectively by conventional therapies. The aim of this study was to investigate the clinical characteristics of Korean rosacea patients with prominent neurological symptoms. The demographic features, medical history, clinical manifestations and treatment modalities of 17 neurogenic rosacea patients who had prominent neurological symptoms and 106 erythematotelangiectatic rosacea (ETR) patients as a control group were investigated. All 17 neurogenic rosacea patients had severe persistent erythema with burning/stinging sensation limited to both cheeks. Among these patients, 94.1% were female (16/17). Heat stimuli (58.8%, 10/17) and stress (52.9%, 9/17) were major aggravating factors. Fourteen of 17 patients (82.3%) improved after receiving anticonvulsants and antidepressants. In conclusion, rosacea patients with severe neurological symptoms show distinct clinical manifestations and should be classified separately, and a different therapeutic approach is necessary for them.

Role of neuroimmune circuits and pruritus in psoriasis

Psoriasis is a chronic inflammatory skin disease presenting with an array of clinical phenotypes, often associated with pruritus. Environmental and psychological stressors can exacerbate psoriasis symptoms and provoke flares. Recent studies suggest a dysfunctional hypothalamic-pituitary-adrenal (HPA) axis in some patients with psoriasis that can result in immune dysregulation. The immune system, in turn, can communicate with the nervous system to induce, maintain or aggravate psoriasis. In the skin, peripheral sensory as well as autonomic nerves control release of inflammatory mediators from dendritic cells, mast cells, T cells or keratinocytes, thereby modulating inflammatory responses and, in case of sensory nerves, pruritus. In response to the environment or stress, cytokines, chemokines, proteases, and neuropeptides fluctuate in psoriasis and influence immune responses as well as nerve activity. Furthermore, immune cells communicate with sensory nerves which control release of cytokines, such as IL-23, that are ultimately involved in psoriasis pathogenesis. Nerves also communicate with keratinocytes to induce epidermal proliferation. Notably, in contrast to recent years the debilitating problem of pruritus in psoriasis has been increasingly appreciated. Thus, investigating neuroimmune communication in psoriasis will not only expand our knowledge about the impact of sensory nerves in inflammation and pruritus and give new insights into the impact of environmental factors activating neuroimmune circuits or of stress in psoriasis, but may also lead to novel therapies. This review summarizes the relevant literature on the role of neuroimmune circuits, stress and how the central HPA axis and its peripheral equivalent in the skin, impact psoriasis.

Standard management options for rosacea: The 2019 update by the National Rosacea Society Expert Committee

In 2017, a National Rosacea Society Expert Committee developed and published an updated classification of rosacea to reflect current insights into rosacea pathogenesis, pathophysiology, and management. These developments suggest that a multivariate disease process underlies the various clinical manifestations of the disorder. The new system is consequently based on phenotypes that link to this process, providing clear parameters for research and diagnosis as well as encouraging clinicians to assess and treat the disorder as it may occur in each individual. Meanwhile, a range of therapies has become available for rosacea, and their roles have been increasingly defined in clinical practice as the disorder has become more widely recognized. This update is intended to provide a comprehensive summary of management options, including expert evaluations, to serve as a guide for tailoring treatment and care on an individual basis to achieve optimal patient outcomes.

Neurotransmitters, neuropeptides and their receptors interact with immune response in healthy and psoriatic skin

Psoriasis is a chronic inflammatory disease with a multifactorial origin that affects the skin. It is characterized by keratinocyte hyperproliferation, which results in erythemato-squamous plaques. Just as the immune system plays a fundamental role in psoriasis physiopathology, the nervous system maintains the inflammatory process through the neuropeptides and neurotransmitters synthesis, as histamine, serotonin, calcitonin gene-related peptide, nerve growth factor, vasoactive intestinal peptide, substance P, adenosine, glucagon-like peptide, somatostatin and pituitary adenylate cyclase polypeptide. In patients with psoriasis, the systemic or in situ expression of these chemical mediators and their receptors are altered, which affects the clinical activity of patients due to its link to the immune system, provoking neurogenic inflammation. It is important to establish the role of the nervous system since it could represent a therapeutic alternative for psoriasis patients. The aim of this review is to offer a detailed review of the current literature about the neuropeptides and neurotransmitters involved in the physiopathology of psoriasis.

Rosacea: a wholistic review and update from pathogenesis to diagnosis and therapy

Rosacea is a chronic inflammatory disorder of the central face with multiple overlapping presentations. Recent advancements are reshaping our understanding of rosacea from both a pathophysiologic perspective and clinical approach to therapy, introducing novel agents that have improved patient outcomes and reduced morbidity. In this article, we aim to outline the advancements in understanding, diagnosing, and managing rosacea and to familiarize physicians with the literature, thereby allowing us to better practice safe and effective medicine.

Novel charged sodium and calcium channel inhibitor active against neurogenic inflammation

Voltage-dependent sodium and calcium channels in pain-initiating nociceptor neurons are attractive targets for new analgesics. We made a permanently charged cationic derivative of an N-type calcium channel-inhibitor. Unlike cationic derivatives of local anesthetic sodium channel blockers like QX-314, this cationic compound inhibited N-type calcium channels more effectively with extracellular than intracellular application. Surprisingly, the compound is also a highly effective sodium channel inhibitor when applied extracellularly, producing more potent inhibition than lidocaine or bupivacaine. The charged inhibitor produced potent and long-lasting analgesia in mouse models of incisional wound and inflammatory pain, inhibited release of the neuropeptide calcitonin gene-related peptide (CGRP) from dorsal root ganglion neurons, and reduced inflammation in a mouse model of allergic asthma, which has a strong neurogenic component. The results show that some cationic molecules applied extracellularly can powerfully inhibit both sodium channels and calcium channels, thereby blocking both nociceptor excitability and pro-inflammatory peptide release.

Mammalian Transient Receptor Potential TRPA1 Channels: From Structure to Disease

The transient receptor potential ankyrin (TRPA) channels are Ca²⁺-permeable nonselective cation channels remarkably conserved through the animal kingdom. Mammals have only one member, TRPA1, which is widely expressed in sensory neurons and in non-neuronal cells (such as epithelial cells and hair cells). TRPA1 owes its name to the presence of 14 ankyrin repeats located in the NH₂ terminus of the channel, an unusual structural feature that may be relevant to its interactions with intracellular components. TRPA1 is primarily involved in the detection of an extremely wide variety of exogenous stimuli that may produce cellular damage. This includes a plethora of electrophilic compounds that interact with nucleophilic amino acid residues in the channel and many other chemically unrelated compounds whose only common feature seems to be their ability to partition in the plasma membrane. TRPA1 has been reported to be activated by cold, heat, and mechanical stimuli, and its function is modulated by multiple factors, including Ca²⁺, trace metals, pH, and reactive oxygen, nitrogen, and carbonyl species. TRPA1 is involved in acute and chronic pain as well as inflammation, plays key roles in the pathophysiology of nearly all organ systems, and is an attractive target for the treatment of related diseases. Here we review the current knowledge about the mammalian TRPA1 channel, linking its unique structure, widely tuned sensory properties, and complex regulation to its roles in multiple pathophysiological conditions.

Skin Acute Wound Healing: A Comprehensive Review

Experimental work of the last two decades has revealed the general steps of the wound healing process. This complex network has been organized in three sequential and overlapping steps. The first step of the inflammatory phase is an immediate response to injury; primary sensory neurons sense injury and send danger signals to the brain, to stop bleeding and start inflammation. The following target of the inflammatory phase, led by the peripheral blood mononuclear cells, is to eliminate the pathogens and clean the wound. Once this is completed, the inflammatory phase is resolved and homeostasis is restored. The aim of the proliferative phase, the second phase, is to repair wound damage and begin tissue remodeling. Fibroplasia, reepithelialization, angiogenesis, and peripheral nerve repair are the central actions of this phase. Lastly, the objective of the final phase is to complete tissue remodeling and restore skin integrity. This review provides present day information regarding the status of the participant cells, extracellular matrix, cytokines, chemokines, and growth factors, as well as their interactions with the microenvironment during the wound healing process.

Potential association between rosacea and cancer: A study in a medical center in southern China

Growing evidence suggests that rosacea increases the risk of systemic diseases, but studies of the relationships between rosacea and cancer are rare. Aimed to assess the relationship between rosacea and cancer, a total of 7548 patients with confirmed internal malignancies and 8340 cancer-free individuals aged 18 years or more were included in this study from November 2015 to October 2017. Clinical characteristics, personal history and laboratory data were recorded when patients were diagnosed with rosacea. Logistic regression analyses were performed to analyze associations between cancer and rosacea. We found rosacea significantly affected more women than men in both cancer and cancer-free group. The data showed there was no relationship between rosacea and lung, gastrointestinal, nasopharyngeal and gynecological cancer. However, rosacea was significantly associated with the increased risk of breast cancer and glioma, but negatively associated with the risk of hematological cancer. Of the 190 female breast cancer patients with rosacea, 98.95% had the erythematotelangiectatic subtype of rosacea, 48.42% had chloasma and 76.31% of them were Fitzpatrick skin type III and IV. In our binary regression model, breast cancer patients with rosacea had a higher prevalence of estrogen receptor-positive status, lower high-density lipoprotein levels and higher low-density lipoprotein than patients with breast cancer but no rosacea. Our findings indicate that rosacea is significantly associated with higher incidence of breast cancer, glioma and lower prevalence of hematological cancer.

Clinical picture, diagnosis and treatment of rosacea, complicated by Demodex mites

The article analyzes the clinical picture and course of rosacea in patients with Demodex mites. It presents the advantages of using the method of confocal laser scanning microscopy over the method of light microscopy of facial skin scrapes. The aimes were to study the influence of Demodex mites on the clinical picture and course of rosacea; to compare laboratory and instrumental diagnostic methods for detecting Demodex mites; to evaluate the effectiveness of external therapy aimed at eliminating Demodex mites. 212 people were examined. The study included healthy patients, patients with a diagnosis of rosacea with the presence and absence of Demodex. The presence of Demodex mites was confirmed by two methods of study (light microscopy of skin scrapes and confocal laser scanning in vivo microscopy). Demodex mites promote the development of acute-inflammatory morphological elements, increase the duration of the condition (more than 5 years, P<0.01) and the probability of recurrence (from 1 to 3 relapses in 39.5% of patients, P<0.05), resulting in a decrease in the quality of life of patients (dermatology life quality index is 12.5±4.5, P<0.05). Antiparasitic drug ivermectin, in the form of an external form, at a concentration of 1% has a high therapeutic efficacy (in 93.3% of cases). Demodex folliculorum shows signs of parasitism, while Demodex folliculorum brevis is a saprophyte. The severity of the condition does not depend on the quantitative load of the mites in the scrape. As an antiparasitic drug, it is recommended to use 1% ivertmectin.

Recent advances in understanding and managing rosacea

Rosacea is a common chronic inflammatory skin disease of the central facial skin and is of unknown origin. Currently, two classifications of rosacea exist that are based on either "preformed" clinical subtypes (erythematotelangiectatic, papulopustular, phymatous, and ocular) or patient-tailored analysis of the presented rosacea phenotype. Rosacea etiology and pathophysiology are poorly understood. However, recent findings indicate that genetic and environmental components can trigger rosacea initiation and aggravation by dysregulation of the innate and adaptive immune system. Trigger factors also lead to the release of various mediators such as keratinocytes (for example, cathelicidin, vascular endothelial growth factor, and endothelin-1), endothelial cells (nitric oxide), mast cells (cathelicidin and matrix metalloproteinases), macrophages (interferon-gamma, tumor necrosis factor, matrix metalloproteinases, and interleukin-26), and T helper type 1 (T _H1) and T _H17 cells. Additionally, trigger factors can directly communicate to the cutaneous nervous system and, by neurovascular and neuro-immune active neuropeptides, lead to the manifestation of rosacea lesions. Here, we aim to summarize the recent advances that preceded the new rosacea classification and address a symptom-based approach in the management of patients with rosacea.

Host Peptidic Hormones Affecting Bacterial Biofilm Formation and Virulence

Bacterial biofilms constitute a critical problem in hospitals, especially in resuscitation units or for immunocompromised patients, since bacteria embedded in their own matrix are not only protected against antibiotics but also develop resistant variant strains. In the last decade, an original approach to prevent biofilm formation has consisted of studying the antibacterial potential of host communication molecules. Thus, some of these compounds have been identified for their ability to modify the biofilm formation of both Gram-negative and Gram-positive bacteria. In addition to their effect on biofilm production, a detailed study of the mechanism of action of these human hormones on bacterial physiology has allowed the identification of new bacterial pathways involved in biofilm formation. In this review, we focus on the impact of neuropeptidic hormones on bacteria, address some future therapeutic issues, and provide a new view of inter-kingdom communication.

The role of nutrition in inflammatory pilosebaceous disorders: Implication of the skin-gut axis

Nutrition plays a critical role in the manifestation and management of inflammatory pilosebaceous disorders. There is rich potential for insight into the impact of dietary effects on the pathophysiology of inflammatory pilosebaceous disorders including acne vulgaris, hidradenitis suppurativa, rosacea, and the closely related seborrhoeic dermatitis. Acne vulgaris and hidradenitis suppurativa are thought to have similar diet-modulating pathogenic pathways. Western diet influences Acne vulgaris and hidradenitis suppurativa by increasing insulin and modulating FOX01/mTOR, resulting in over-expression of cytokeratins, hyperproliferation of keratinocytes, and hypercornification of the follicular wall. Key receptors in rosacea are alternatively activated by UV radiation, hot beverages, spicy foods, vanilla, cinnamon, caffeine, alcohol, cold temperatures, and niacin- and formalin-containing foods, to increase oedema and flushing, resulting in erythema, telangiectasia, and warmth, characteristic features of the condition. Seborrhoeic dermatitis, while not a follicular disorder, is closely related, and can be modulated by dietary influences, such as biotin and probiotics. This overview summarizes the role that nutrition plays on these disorders, and identifies dietary modifications as potential adjunctive therapies.

Chronic adriamycin treatment impairs CGRP-mediated functions of meningeal sensory nerves

Adriamycin is a potent anthracycline-type antitumor agent, but it also exerts potentially serious side effects due to its cardiotoxic and neurotoxic propensity. Multiple impairments in sensory nerve functions have been recently reported in various rat models. The present experiments were initiated in an attempt to reveal adriamycin-induced changes in sensory effector functions of chemosensitive meningeal afferents. Meningeal blood flow was measured with laser Doppler flowmetry in the parietal dura mater of adult male Wistar rats. The dura mater was repeatedly stimulated by topical applications of capsaicin, a transient receptor potential vanilloid 1 (TRPV1) receptor agonist, or acrolein, a transient receptor potential ankyrin 1 (TRPA1) receptor agonist, which induce the release of calcitonin gene-related peptide (CGRP) from meningeal afferents. The blood flow increasing effects of CGRP, histamine, acetylcholine and forskolin were also measured. Capsaicin- and acrolein-induced CGRP release was measured with enzyme-linked immunoassay in an ex vivo dura mater preparation. TRPV1 content of trigeminal ganglia and TRPV1-, CGRP- and CGRP receptor component-immunoreactive structures were examined in dura mater samples obtained from control and adriamycin-treated rats. The vasodilator effects of capsaicin, acrolein and CGRP were significantly reduced in adriamycin-treated animals while histamine-, acetylcholine- and forskolin-induced vasodilatation were unaffected. Measurements of CGRP release in an ex vivo dura mater preparation revealed an altered dynamic upon repeated stimulations of TRPV1 and TRPA1 receptors. In whole-mount dura mater preparations immunohistochemistry revealed altered CGRP receptor component protein (RCP)-immunoreactivity in adriamycin-treated animals, while CGRP receptor activity modifying protein (RAMP1)-, TRPV1- and CGRP-immunostaining were left apparently unaltered. Adriamycin-treatment slightly reduced TRPV1 protein content of trigeminal ganglia. The present findings demonstrate that adriamycin-treatment alters the function of the trigeminovascular system leading to reduced meningeal sensory neurogenic vasodilatation that may affect the local regulatory and protective mechanisms of chemosensitive afferents leading to alterations in tissue integrity.

Skin Barrier and Calcium

Epidermal barrier formation and the maintenance of barrier homeostasis are essential to protect us from the external environments and organisms. Moreover, impaired keratinocytes differentiation and dysfunctional skin barrier can be the primary causes or aggravating factors for many inflammatory skin diseases including atopic dermatitis and psoriasis. Therefore, understanding the regulation mechanisms of keratinocytes differentiation and skin barrier homeostasis is important to understand many skin diseases and establish an effective treatment strategy. Calcium ions (Ca²⁺) and their concentration gradient in the epidermis are essential in regulating many skin functions, including keratinocyte differentiation, skin barrier formation, and permeability barrier homeostasis. Recent studies have suggested that the intracellular Ca²⁺ stores such as the endoplasmic reticulum (ER) are the major components that form the epidermal calcium gradient and the ER calcium homeostasis is crucial for regulating keratinocytes differentiation, intercellular junction formation, antimicrobial barrier, and permeability barrier homeostasis. Thus, both Ca²⁺ release from intracellular stores, such as the ER and Ca²⁺ influx mechanisms are important in skin barrier. In addition, growing evidences identified the functional existence and the role of many types of calcium channels which mediate calcium flux in keratinocytes. In this review, the origin of epidermal calcium gradient and their role in the formation and regulation of skin barrier are focused. We also focus on the role of ER calcium homeostasis in skin barrier. Furthermore, the distribution and role of epidermal calcium channels, including transient receptor potential channels, store-operated calcium entry channel Orai1, and voltage-gated calcium channels in skin barrier are discussed.

Standard classification and pathophysiology of rosacea: The 2017 update by the National Rosacea Society Expert Committee

In 2002, the National Rosacea Society assembled an expert committee to develop the first standard classification of rosacea. This original classification was intended to be updated as scientific knowledge and clinical experience increased. Over the last 15 years, significant new insights into rosacea's pathogenesis and pathophysiology have emerged, and the disorder is now widely addressed in clinical practice. Growing knowledge of rosacea's pathophysiology has established that a consistent multivariate disease process underlies the various clinical manifestations of this disorder, and the clinical significance of each of these elements is increasing as more is understood. This review proposes an updated standard classification of rosacea that is based on phenotypes linked to our increased understanding of disease pathophysiology. This updated classification is intended to provide clearer parameters to conduct investigations, guide diagnosis, and improve treatment.

Sensitive skin: review of an ascending concept

Sensitive skin is a condition characterized by stinging, burning and itching sensations. The diagnosis, pathophysiology and treatment of sensitive skin are still under discussion. In the last years, studies on its epidemiology have been performed, showing a high prevalence and impact on quality of life. Brazilian population was also considered in these studies. Cosmetics, climate changes and skin barrier impairment are the main factors that contribute for skin hyperreactivity. New studies are trying to bring new knowledge about the theme. This review will describe data on epidemiology, triggering factors, pathophysiology, diagnosis and treatment.

Diet and rosacea: the role of dietary change in the management of rosacea

Dietary change may play a role in the therapy of rosacea. Certain foods and beverages may act as "triggers" for rosacea exacerbations. These may be divided into heat-related, alcohol-related, capsaicin-related, and cinnamaldehyde-related. One potential pathogenic mechanism may be via the activation of transient receptor potential cation channels, which result in neurogenic vasodilatation. Further research is needed on the role of the gut skin connection in rosacea. Epidemiologic studies suggest that patients with rosacea have a higher prevalence of gastrointestinal disease, and one study reported improvement in rosacea following successful treatment of small intestinal bacterial overgrowth. While further research is required in this area, patients may be advised on measures to support a healthy gut microbiome, including the consumption of a fiber-rich (prebiotic) diet.

The relationship between migraine and rosacea: Systematic review and meta-analysis

Objective

To systematically review the association between migraine and rosacea.

Background

Migraine is a complex disorder with episodes of headache, nausea, photo- and phonophobia. Rosacea is an inflammatory skin condition with flushing, erythema, telangiectasia, papules, and pustules. Both are chronic disorders with exacerbations of symptoms almost exclusively in areas innervated by the trigeminal nerve. Previous studies found an association between these disorders. We review these findings, provide a meta-analysis, and discuss possible pathophysiological commonalities.

Methods

A search through PubMed and EMBASE was undertaken for studies investigating the association between all forms of migraine and rosacea published until November 2016, and meta-analysis of eligible studies.

Results

Nine studies on eight populations were identified. Studies differed in methodology and diagnostic process, but all investigated co-occurrence of migraine and rosacea. Four studies were eligible for meta-analysis, resulting in a pooled odds ratio of 1.96 (95% confidence interval 1.41–2.72) for migraine in a rosacea population compared to a non-rosacea population.

Conclusion

Our meta-analysis confirmed an association in occurrence of migraine and rosacea. Future studies should specifically investigate possible shared pathophysiological mechanisms between the two disorders.

Swiss S1 guideline for the treatment of rosacea

Rosacea (in German sometimes called 'Kupferfinne', in French 'Couperose' and in Italian 'Copparosa') is a chronic and frequently relapsing inflammatory skin disease primarily affecting the central areas of the face. Its geographic prevalence varies from 1% to 22%. The differential diagnosis is wide, and the treatment is sometimes difficult and varies by stage of rosacea. For erythematous lesions and telangiectasia, intense pulsed light (IPL) therapy and lasers are popular treatment option. In addition, a vasoconstrictor agent, brimonidine, has recently been developed. For papulopustular rosacea, topical antibiotics, topical and systemic retinoids, as well as systemic antibiotics are used. A topical acaricidal agent, ivermectin, has undergone clinical development and is now on the market. In the later stages, hyperplasia of the sebaceous glands develops, resulting in phymatous growths such as the frequently observed bulbous nose or rhinophyma. Ablative laser treatments have largely replaced classical abrasive tools. Here, we reviewed the current evidence on the treatment of rosacea, provide a guideline (S1 level) and discuss the differential diagnosis of rosacea.

Pathogenesis and clinical presentation of rosacea as a key for a symptom-oriented therapy

Rosacea is a common chronic inflammatory skin disorder that typically occurs in adults and affects the face. Synonyms of rosacea include "acne rosacea", "couperose" and "facial erythrosis", in German also "Kupferfinne" and "Rotfinne". The disorder is characterised by a chronic and flaring course and is caused by a genetically predisposed, multifactorial process. A higher incidence is seen in people with fair skin and a positive family history. The characteristic rosacea symptoms manifest primarily, but not exclusively centrofacially, with forehead, nose, chin and cheeks significantly affected. Based on the various main symptoms a classification of the individual clinical pictures can be performed. However, a classification often does not reflect the clinical reality, since the various symptoms commonly coexist. The present review provides an introduction on pathogenesis and clinical manifestations of rosacea and prefers a symptom-oriented therapy approach.

Pathogenese und Klinik der Rosazea als Schlüssel für eine symptomorientierte Therapie

Rosazea ist eine häufige chronisch-entzündliche Hauterkrankung, die typischerweise bei Erwachsenen vorkommt und das Gesicht betrifft. Synonyme der Rosazea sind Acne rosacea, Kupferfinne, Rotfinne, Couperose und Rosacea. Die Erkrankung ist durch einen chronischen und schubartigen Verlauf gekennzeichnet und wird durch ein genetisch prädisponiertes, multifaktorielles Geschehen bedingt. Ein vermehrtes Auftreten wird bei hellem Hauttyp und positiver Familienanamnese verzeichnet. Die charakteristischen Rosazea-Symptome manifestieren sich vorwiegend, aber nicht ausschließlich zentrofazial, wobei Stirn, Nase, Kinn und die Wangen maßgeblich betroffen sind. Dabei werden unterschiedliche Hauptsymptome voneinander unterschieden, anhand derer eine Klassifikation der verschiedenen klinischen Bilder vorgenommen werden kann. Eine Klassifizierung wird oftmals jedoch nicht der klinischen Realität gerecht, da die verschiedenen Symptome häufig gemeinsam auftreten. Diese Übersichtarbeit führt in die Pathogenese und Klinik der Rosazea ein und plädiert für einen symptomorientierten Therapieansatz.

TRPV1 and TRPA1 in cutaneous neurogenic and chronic inflammation: pro-inflammatory response induced by their activation and their sensitization

Cutaneous neurogenic inflammation (CNI) is inflammation that is induced (or enhanced) in the skin by the release of neuropeptides from sensory nerve endings. Clinical manifestations are mainly sensory and vascular disorders such as pruritus and erythema. Transient receptor potential vanilloid 1 and ankyrin 1 (TRPV1 and TRPA1, respectively) are non-selective cation channels known to specifically participate in pain and CNI. Both TRPV1 and TRPA1 are co-expressed in a large subset of sensory nerves, where they integrate numerous noxious stimuli. It is now clear that the expression of both channels also extends far beyond the sensory nerves in the skin, occuring also in keratinocytes, mast cells, dendritic cells, and endothelial cells. In these non-neuronal cells, TRPV1 and TRPA1 also act as nociceptive sensors and potentiate the inflammatory process. This review discusses the role of TRPV1 and TRPA1 in the modulation of inflammatory genes that leads to or maintains CNI in sensory neurons and non-neuronal skin cells. In addition, this review provides a summary of current research on the intracellular sensitization pathways of both TRP channels by other endogenous inflammatory mediators that promote the self-maintenance of CNI.

Substance P and Calcitonin Gene-Related Peptide: Key Regulators of Cutaneous Microbiota Homeostasis

Neurohormones diffuse in sweat and epidermis leading skin bacterial microflora to be largely exposed to these host factors. Bacteria can sense a multitude of neurohormones, but their role in skin homeostasis was only investigated recently. The first study focused on substance P (SP), a neuropeptide produced in abundance by skin nerve terminals. SP is without effect on the growth of Gram-positive (Bacillus cereus, Staphylococcus aureus, and Staphylococcus epidermidis) and Gram-negative (Pseudomonas fluorescens) bacteria. However, SP is stimulating the virulence of Bacillus and Staphylococci. The action of SP is highly specific with a threshold below the nanomolar level. Mechanisms involved in the response to SP are different between bacteria although they are all leading to increased adhesion and/or virulence. The moonlighting protein EfTu was identified as the SP-binding site in B. cereus and Staphylococci. In skin nerve terminals, SP is co-secreted with the calcitonin gene-related peptide (CGRP), which was shown to modulate the virulence of S. epidermidis. This effect is antagonized by SP. Identification of the CGRP sensor, DnaK, allowed understanding this phenomenon as EfTu and DnaK are apparently exported from the bacterium through a common system before acting as SP and CGRP sensors. Many other neuropeptides are expressed in skin, and their potential effects on skin bacteria remain to be investigated. Integration of these host signals by the cutaneous microbiota now appears as a key parameter in skin homeostasis.

Spotlight on brimonidine topical gel 0.33% for facial erythema of rosacea: safety, efficacy, and patient acceptability

BACKGROUND

Brimonidine tartrate is a highly selective alpha 2 agonist that induces direct vasoconstriction of small arteries and veins, thereby reducing vasodilation and edema.

OBJECTIVE

To review the current literature regarding the safety, efficacy, and patient acceptability of brimonidine 0.33% gel.

METHODS

A PubMed search was performed using the terms brimonidine 0.33% gel, rosacea, safety, efficacy, and acceptability. Peer-reviewed clinical trials and case reports from 2012 to 2016 were screened for inclusion of safety, efficacy, and/or patient acceptability data.

RESULTS

Brimonidine topical gel 0.33% is associated with mild, transient skin-related adverse reactions. Efficacy may be achieved within 30 minutes of administration with maximal reductions in erythema 3-6 hours after administration. Patient satisfaction with use of brimonidine topical gel is superior to vehicle gel for facial appearance, treatment effect, facial redness, and daily control of facial redness.

LIMITATIONS

Studies were typically limited to 1-year follow-up. Only one study has examined the use of brimonidine topical gel in combination with other rosacea and acne medications.

DISCUSSION

Brimonidine topical gel 0.33% is a safe, effective, and patient-accepted treatment for facial erythema of rosacea.