Perfusion measured by laser speckle contrast imaging as a predictor for expansion of psoriasis lesions.

BACKGROUND: Skin microvasculature changes are crucial in psoriasis development and correlate with perfusion. The noninvasive Handheld Perfusion Imager (HAPI) examines microvascular skin perfusion in large body areas using laser speckle contrast imaging (LSCI). OBJECTIVES: To (i) assess whether increased perilesional perfusion and perfusion inhomogeneity are predictors for expansion of psoriasis lesions and (ii) assess feasibility of the HAPI system in a mounted modality. METHODS: In this interventional pilot study in adults with unstable plaque psoriasis, HAPI measurements and color photographs were performed for lesions present on one body region at week 0, 2, 4, 6 and 8. The presence of increased perilesional perfusion and perfusion inhomogeneity was determined. Clinical outcome was categorized as increased, stable or decreased lesion surface between visits. Patient feedback was collected on a 10-point scale. RESULTS: In total, 110 lesions with a median follow-up of 6 (IQR 6.0) weeks were assessed in 6 patients with unstable plaque psoriasis. Perfusion data was matched to 281 clinical outcomes after two weeks. A mixed multinomial logistic regression model revealed a predictive value of perilesional increased perfusion (OR 9.90; p < 0.001) and perfusion inhomogeneity (OR 2.39; p = 0.027) on lesion expansion after two weeks compared to lesion stability. HAPI measurements were considered fast, patient-friendly and important by patients. CONCLUSION: Visualization of increased perilesional perfusion and perfusion inhomogeneity by noninvasive whole field LSCI holds potential for prediction of psoriatic lesion expansion. Furthermore, the HAPI is a feasible and patient-friendly tool.

Carboxamide Derivatives Are Potential Therapeutic AHR Ligands for Restoring IL-4 Mediated Repression of Epidermal Differentiation Proteins.

Atopic dermatitis (AD) is a common T-helper 2 (Th2) lymphocyte-mediated chronic inflammatory skin disease characterized by disturbed epidermal differentiation (e.g., filaggrin (FLG) expression) and diminished skin barrier function. Therapeutics targeting the aryl hydrocarbon receptor (AHR), such as coal tar and tapinarof, are effective in AD, yet new receptor ligands with improved potency or bioavailability are in demand to expand the AHR-targeting therapeutic arsenal. We found that carboxamide derivatives from laquinimod, tasquinimod, and roquinimex can activate AHR signaling at low nanomolar concentrations. Tasquinimod derivative (IMA-06504) and its prodrug (IMA-07101) provided full agonist activity and were most effective to induce FLG and other epidermal differentiation proteins, and counteracted IL-4 mediated repression of terminal differentiation. Partial agonist activity by other derivatives was less efficacious. The previously reported beneficial safety profile of these novel small molecules, and the herein reported therapeutic potential of specific carboxamide derivatives, provides a solid rationale for further preclinical assertation.

Immune responses to azacytidine in animal models of inflammatory disorders: a systematic review.

Inflammatory disorders like diabetes, systemic lupus erythematodes, inflammatory lung diseases, rheumatoid arthritis and multiple sclerosis, but also rejection of transplanted organs and GvHD, form a major burden of disease. Current classes of immune suppressive drugs to treat these disorders are never curative and side effects are common. Therefore there is a need for new drugs with improved and more targeted modes of action. Potential candidates are the DNA methyl transferase inhibitor 5-azacytidine (Aza) and its derivative 5-aza 2'deoxycitidine (DAC). Aza and DAC have been tested in several pre-clinical in vivo studies. In order to obtain an overview of disorders for which Aza and/or DAC can be a potential treatment, and to find out where information is lacking, we systematically reviewed pre-clinical animal studies assessing Aza or DAC as a potential therapy for distinct inflammatory disorders. Also, study quality and risk of bias was systematically assessed. In the 35 identified studies, we show that both Aza and DAC do not only seem to be able to alleviate a number of inflammatory disorders, but also prevent solid organ rejection and GvHD in in vivo pre-clinical animal models. Aza/DAC are known to upregulate FOXP3, a master transcription factor for Treg, in vitro. Seventeen studies described the effect on Treg, of which 16 studies showed an increase in Treg. Increasing Treg therefore seems to be a common mechanism in preventing inflammatory disorders by Aza/DAC. We also found, however, that many essential methodological details were poorly reported leading to an unclear risk of bias. Therefore, reported effects might be an overestimation of the true effect.

Vesicular hand eczema transcriptome analysis provides insights into its pathophysiology.

Hand eczema is a common inflammatory skin condition of the hands whose pathogenesis is largely unknown. More insight and knowledge of the disease on a more fundamental level might lead to a better understanding of the biological processes involved, which could provide possible new treatment strategies. We aimed to profile the transcriptome of lesional palmar epidermal skin of patients suffering from vesicular hand eczema using RNA-sequencing. RNA-sequencing was performed to identify differentially expressed genes in lesional vs. non-lesional palmar epidermal skin from a group of patients with vesicular hand eczema compared to healthy controls. Comprehensive real-time quantitative PCR analyses and immunohistochemistry were used for validation of candidate genes and protein profiles for vesicular hand eczema. Overall, a significant and high expression of genes/proteins involved in keratinocyte host defense and inflammation was found in lesional skin. Furthermore, we detected several molecules, both up or downregulated in lesional skin, which are involved in epidermal differentiation. Immune signalling genes were found to be upregulated in lesional skin, albeit with relatively low expression levels. Non-lesional patient skin showed no significant differences compared to healthy control skin. Lesional vesicular hand eczema skin shows a distinct expression profile compared to non-lesional skin and healthy control skin. Notably, the overall results indicate a large overlap between vesicular hand eczema and earlier reported atopic dermatitis lesional transcriptome profiles, which suggests that treatments for atopic dermatitis could also be effective in (vesicular) hand eczema.

Value of GPSkin for the measurement of skin barrier impairment and for monitoring of rosacea treatment in daily practice.

BACKGROUND: Stratum corneum hydration (SCH) and transepidermal water loss (TEWL) provide useful information about skin barrier function. This study aimed to determine the value of GPSkin Pro, a new handheld device determining both SCH and TEWL, to measure skin barrier impairment and to monitor barrier function in rosacea in daily practice. MATERIALS AND METHODS: Two pilots were performed. Pilot 1: in 27 healthy participants, GPSkin SCH and TEWL were compared to Aquaflux® and Epsilon® values at the forearm before and after skin barrier perturbation via tapestripping. Moreover, GPSkin values were measured at both cheeks without intervention. Pilot 2: in 16 rosacea patients, GPSkin measurements were performed at the forearm, and at both cheeks before and during anti-inflammatory treatment. They were compared to clinical symptoms and to GPSkin values from pilot 1. RESULTS: Pilot 1: after merging data from before and after tapestripping, a strong correlation was observed between GPSkin TEWL and Aquaflux® (Rs  = 0.9256), and GPSkin SCH and Epsilon® (Rs  = 0.8798). Pilot 2: SCH was significantly lower at the cheeks of rosacea patients compared to controls, with a normalizing trend during successful treatment. TEWL was comparable among patients and controls and did not change during treatment at all locations. CONCLUSION: The GPSkin determines TEWL and SCH accurately in healthy and impaired skin barrier state and can monitor skin barrier function in rosacea during treatment. The GPSkin device is much more practical compared to previous skin barrier tools when used in clinical practice. Its further validation in other inflammatory skin diseases is recommended.

Skin Surface Protein Detection by Transdermal Analysis Patches in Pediatric Psoriasis.

INTRODUCTION: Transdermal analysis patches (TAPs) noninvasively measure soluble proteins in the stratum corneum. Ultimately, such local protein profiles could benefit the search for biomarkers to improve personalized treatment in psoriasis. This study aimed to explore the patient friendliness and protein detection by TAP in pediatric psoriasis in daily clinical practice. METHODS: In this observational study, TAPs measuring CXC chemokine ligand (CXCL)-1/2, CC chemokine ligand (CCL)-27, interleukin (IL)-1RA, IL-23, IL-1α, IL-8, IL-4, IL-22, IL-17A, vascular endothelial growth factor (VEGF), human beta-defensin (hBD)-2, hBD-1, and kallikrein-related peptidase (KLK)-5 were applied on lesional, peri-lesional, and non-lesional skin sites of psoriasis patients aged >5 to <18 years. Discomfort during TAP removal as an indicator for patient friendliness was assessed by visual analogue scale (VAS; range 0-10). RESULTS: Thirty-two patients (median age 14.0 years) were included, of which 19 were treated with solely topical agents and 13 with systemic treatment. The median VAS of discomfort during TAP removal was 1.0 (interquartile range 1.0). Significantly higher levels in lesional versus non-lesional skin were found for IL-1RA, VEGF, CXCL-1/2, hBD-2, and IL-8, whereas lower levels were found for IL-1α. Skin surface proteins were measured in both treatment groups, with significant higher lesional levels of KLK-5, IL-1RA, hBD-2, IL-1α, IL-23, and CCL-27 in the systemic treatment group. CONCLUSION: The TAP platform holds the potential for patient-friendly and noninvasive monitoring of skin-derived proteins in pediatric psoriasis patients in daily clinical practice.

Evaluation of a simple image-based tool to quantify facial erythema in rosacea during treatment.

BACKGROUND: Facial erythema is a common symptom in rosacea. To overcome subjectivity in scoring erythema severity, objective redness quantification is desirable. This study evaluated an image-based erythema quantification tool to monitor facial erythema in rosacea patients during treatment and compared these values to clinical scores. MATERIALS AND METHODS: Twenty-one rosacea patients were treated with topical ivermectin for 16 weeks. Clinical erythema scores and clinical photographs were taken at week 0, 6, 16 and 28. Using ImageJ, RGB images were split into red, green and blue channels to measure the green/red ratio of lesional skin compared with a green sticker. With CIELAB colour space, a* (indicating colour from green to red) of a lesional and non-lesional facial site was measured, calculating ∆a*. Interobserver concordance and correlation between quantitative and clinical erythema values were determined. RESULTS: Treatment resulted in reduction of clinical erythema scores. No significant changes in red/green ratios were measured. Lesional a* and ∆a* significantly decreased from baseline to week 16 and 28 (P < .05). A weak correlation existed between clinical scores and lesional a* (Rs  = 0.37), and between clinical scores and ∆a* (Rs  = 0.30), with a clear trend towards higher a* and ∆a* for higher clinical scores. Interobserver correlation was high (R2  = 0.82). CONCLUSION: ImageJ is a simple, rapid, objective and reproducible tool to monitor erythema in rosacea patients during treatment. The photographs allow retrospective analysis, evaluation of large and small lesions, and discrimination of subtle redness differences. We recommend using lesional a* to monitor erythema of inflammatory dermatoses in clinical practice.

Deficiency of the human cysteine protease inhibitor cystatin M/E causes hypotrichosis and dry skin.

PURPOSE: We aimed to assess the biological and clinical significance of the human cysteine protease inhibitor cystatin M/E, encoded by the CTS6 gene, in diseases of human hair and skin. METHODS: Exome and Sanger sequencing was performed to reveal the genetic cause in two related patients with hypotrichosis. Immunohistochemical, biophysical, and biochemical measurements were performed on patient skin and 3D-reconstructed skin from patient-derived keratinocytes. RESULTS: We identified a homozygous variant c.361C>T (p.Gln121*), resulting in a premature stop codon in exon 2 of CST6 associated with hypotrichosis, eczema, blepharitis, photophobia and impaired sweating. Enzyme assays using recombinant mutant cystatin M/E protein, generated by site-directed mutagenesis, revealed that this p.Gln121* variant was unable to inhibit any of its three target proteases (legumain and cathepsins L and V). Three-dimensional protein structure prediction confirmed the disturbance of the protease/inhibitor binding sites of legumain and cathepsins L and V in the p.Gln121* variant. CONCLUSION: The herein characterized autosomal recessive hypotrichosis syndrome indicates an important role of human cystatin M/E in epidermal homeostasis and hair follicle morphogenesis.

Assessment of reflectance confocal microscopy for non-invasive selection of optimal ovarian cortex fragments for autotransplantation.

RESEARCH QUESTION: Can reflectance confocal microscopy (RCM) be used to determine follicle density in human ovarian cortex fragments that are intended for fertility restoration? DESIGN: RCM was used on living cortex tissue fragments derived from five bovine ovaries and 13 human ovaries. All tissue fragments were cryopreserved and thawed before RCM analysis. Follicle numbers and distribution were determined by RCM and histology. Before and after RCM, general tissue viability and follicle integrity were assessed by a glucose uptake assay and neutral red staining, respectively. RESULTS: RCM can detect all stages of follicle development in living ovarian tissue to a maximum depth of 250 µm. In bovine tissue, all follicles were located within this 0-250 µm range. In human ovarian tissue, follicles were also present below the 250 µm RCM threshold, implying that only a percentage of the total number of follicles could be detected with RCM. The percentage of follicles detected by RCM appeared to be age dependent. The RCM procedure did not affect the glucose uptake by the tissue, whereas neutral red staining indicated a high level of follicle survival. CONCLUSION: In this proof of concept study, we have shown that RCM is a promising technique to determine the density of follicles ex vivo in living human ovarian cortex fragments, apparently without compromising the vitality of the tissue. Safety studies and further optimization of the RCM technique with a focus on increasing the penetration depth are required before clinical use of RCM.

Anatomical site variation of water content in human skin measured by the Epsilon: A pilot study.

BACKGROUND: This pilot study aimed to investigate the anatomical site variation of water content of the stratum corneum (SC) on the body by measuring skin capacitance with the Epsilon, a new generation corneometer with multiple sensors. Secondly, values of the Epsilon were compared to values measured by conventional single sensor corneometers. METHODS: The hydration status of SC was measured in 15 healthy Caucasian volunteers with the Epsilon at five body sites (cheek, lower forearm, mid-calf, lower back and abdomen). Transepidermal water loss (TEWL) was measured with the Aquaflux to get more insight into the condition of the skin barrier. A literature search was performed to compare Epsilon values with conventional corneometers. RESULTS: The tested anatomical locations showed significant differences in water content (P < 0.001) with large interindividual variations; highest values were found in the cheek (11.64ε) and lowest values in the mid-calf (4.43ε). No correlation between water content and TEWL was found. In general, Epsilon values were lower compared to values of conventional corneometers, with a similar trend. CONCLUSION: This pilot study showed significant variations in water content at different skin locations measured by the Epsilon. Moreover, the Epsilon measured consistent lower values compared to single sensor corneometers. Further validation of the device is recommended.

Development of a Novel Approach to Studying Corneodesmosomes and Stratum Corneum Adhesion: Extending Knowledge on the Pathophysiology of Sensitive Skin.

BACKGROUND/AIMS: Aberrant skin barrier and intercorneocyte adhesion are potential contributors to the pathomechanism of sensitive skin (SS). Here we aimed to develop a novel and easy-to-apply method to analyze corneodesmosomes and to interrogate potential differences between corneocytes of subjects with SS and non-SS (NSS). METHODS: Corneocytes of the volar forearm and upper outer quadrant of the left buttock of SS (n = 10) and NSS (n = 8) subjects were extracted as a function of depth using adhesive tape and stained with anti-desmoglein 1 (DSG1) antibody. The total area of corneocytes and the number and average size of cells per tape was estimated using image processing. RESULTS: The total area of extracted corneocytes and the quantity of DSG1 decreased with depth. The level of decrease, total area of corneocytes, and average area of individual cells differed between anatomical locations. In SS, a larger total area of extracted corneocytes and a larger average cell size per tape was found at all inspected depths. CONCLUSION: The developed novel and easy-to-apply approach allows investigation of corneodesmosome components. We confirm a role of altered corneocytes in the pathomechanism of SS. The disclosed protocol can further be optimized in studies of skin conditions with strongly affected corneodesmosomes.

Noninvasive analysis and minimally invasive in vivo experimental challenges of the skin barrier.

In this review, we aim to give a concise and selective overview of noninvasive biophysical analysis techniques for skin barrier analysis (transepidermal water loss, electrical methods, confocal Raman microspectroscopy, sebumeter, reflectance spectrophotometry, tristimulus colorimetry, diffuse reflectance spectroscopy and reflectance confocal microscopy), including advantages and limitations. Rather than giving an exhaustive description of the many techniques currently available, we show the usefulness of a representative selection of techniques in the functional and morphological evaluation of the skin barrier. Furthermore, we introduce human minimally invasive skin challenging models as a means to study the mechanisms regulating skin homoeostasis and disease and subsequently show how biophysical analysis techniques can be combined with these in vivo skin challenging models in the functional and morphological evaluation of the skin barrier in healthy human skin. We are convinced that the widespread application of biophysical analysis techniques in dermatological practice and in cosmetic sciences will prove invaluable in offering personalized and noninvasive skin treatment solutions. Furthermore, combining the human in vivo challenging models with these novel noninvasive techniques will provide valuable methodology and tools for detailed characterization of the skin barrier in health and disease.

Cathepsin B as a potential cystatin M/E target in the mouse hair follicle.

Deficiency of the cysteine protease inhibitor cystatin M/E (Cst6) in mice leads to disturbed epidermal cornification, impaired barrier function, and neonatal lethality. We report the rescue of the lethal skin phenotype of ichq (Cst6-deficient; Cst6-/-) mice by transgenic, epidermis-specific, reexpression of Cst6 under control of the human involucrin (INV) promoter. Rescued Tg(INV-Cst6)Cst6ichq/ichq mice survive the neonatal phase, but display severe eye pathology and alopecia after 4 mo. We observed keratitis and squamous metaplasia of the corneal epithelium, comparable to Cst6-/-Ctsl+/- mice, as we have reported in other studies. We found the INV promoter to be active in the hair follicle infundibulum; however, we did not observe Cst6 protein expression in the lower regions of the hair follicle in Tg(INV-Cst6)Cst6ichq/ichq mice. This result suggests that unrestricted activity of proteases is involved in disturbance of hair follicle biology, eventually leading to baldness. Using quenched activity-based probes, we identified mouse cathepsin B (CtsB), which is expressed in the lower regions of the hair follicle, as an additional target of mouse Cst6. These data suggest that Cst6 is necessary to control CtsB activity in hair follicle morphogenesis and highlight Cst6-controlled proteolytic pathways as targets for preventing hair loss.-Oortveld, M. A. W., van Vlijmen-Willems, I. M. J. J., Kersten, F. F. J., Cheng, T., Verdoes, M., van Erp, P. E. J., Verbeek, S., Reinheckel, T., Hendriks, W. J. A. J., Schalkwijk, J., Zeeuwen, P. L. J. M. Cathepsin B as a potential cystatin M/E target in the mouse hair follicle.

Effects of blue light on inflammation and skin barrier recovery following acute perturbation. Pilot study results in healthy human subjects.

BACKGROUND/PURPOSE: While growing evidence supports the therapeutic effect of 453 nm blue light in chronic inflammatory skin diseases, data on its effects on acutely perturbed human skin are scarce. In this study, we investigated the impact of 453 nm narrow-band LED light on healthy skin following acute perturbation. METHODS: Tape stripping and histamine iontophoresis were performed on the forearm of 22 healthy volunteers on 2 consecutive weeks. In 1 week, challenges were followed by irradiation for 30 minutes. In the other week (control), no light was administered. Reactions were evaluated up to 72 hours thereafter by transepidermal water loss (TEWL), diffuse reflectance spectroscopy, and skin surface biomarkers. RESULTS: Skin barrier disruption resulted in upregulation of IL-1α at 24 hours after tape stripping (P = .029). In contrast, irradiation abrogated this effect (P > .05). Irradiation also resulted in higher TEWL at 24 hours and in higher b* value at 72 hours after tape stripping compared to the control (P = .034 and P = .018, respectively). At 30 minutes following histamine iontophoresis and irradiation, a trend toward a higher a* value compared to the control was observed (P = .051). CONCLUSION: We provide the first in vivo evidence that blue light at 453 nm exerts biological effects on acutely perturbed healthy human skin.

Minimally-invasive Sampling of Interleukin-1α and Interleukin-1 Receptor Antagonist from the Skin: A Systematic Review of In vivo Studies in Humans.

Interleukin-1α (IL-1α) and its receptor antagonist IL-1RA play a pivotal role in skin homeostasis and disease. Although the use of biopsies to sample these cytokines from human skin is widely employed in dermatological practice, knowledge about less invasive, in vivo sampling methods is scarce. The aim of this study was to provide an overview of such methods by systematically reviewing studies in Medline, EMBASE, Web of Science and Cochrane Library using combinations of the terms "IL-1α", IL-1RA", "skin", "human", including all possible synonyms. Quality was assessed using the STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) checklist. The search, performed on 14 October 2016, revealed 10 different sampling methods, with varying degrees of invasiveness and wide application spectrum, including assessment of both normal and diseased skin, from several body sites. The possibility to sample quantifiable amounts of cytokines from human skin with no or minimal discomfort holds promise for linking clinical outcomes to molecular profiles of skin inflammation.

Histamine Iontophoresis as in vivo Model to Study Human Skin Inflammation with Minimal Barrier Impairment: Pilot Study Results of Application of the Model to a Sensitive Skin Panel.

BACKGROUND/AIMS: Histamine iontophoresis is known to elicit itch and a wheal-and-flare reaction; however, its impact on the skin barrier and underlying compartments has not been thoroughly evaluated yet. The primary objective of this study was to characterize that using immunohistochemistry, biophysical measurements, and image analysis, and secondly, to explore whether skin reactions to this model differ in sensitive skin (SS). METHODS: Eighteen healthy subjects, n = 9 with SS and n = 9 with non-sensitive skin (NSS), were included based on a perception-based questionnaire. Histamine iontophoresis was performed on the buttock, and skin reactions were evaluated up to 72 h after stimulation. RESULTS: The wheal-and-flare peaked at 30 min; after 8 h, no clinical signs were visible. No signs of disruption of the stratum corneum, as well as no increase in the number of Ki67-positive cells emerged, whereas fewer tryptase-positive mast cells and increased epidermal thickness were observed at 1 and 72 h, respectively. SS subjects showed higher perception of itch compared to NSS subjects. CONCLUSION: Histamine iontophoresis is a well-standardized in vivo model to quantitatively study the early stages of cutaneous inflammation with minimal impact on the skin barrier. In line with previous studies, it highlighted increased sensory perceptions in SS.

Sensitive Skin: Assessment of the Skin Barrier Using Confocal Raman Microspectroscopy.

BACKGROUND/AIMS: Sensitive skin (SS), a frequently reported condition in the Western world, has been suggested to be underlined by an impaired skin barrier. The aim of this study was to investigate the skin barrier molecular composition in SS subjects using confocal Raman microspectroscopy (CRS), and to compare it with that of non-SS (NSS) individuals as well as atopic dermatitis (AD) and allergic rhinoconjunctivitis (AR) subjects, who frequently report SS. METHODS: Subjects with SS (n = 29), NSS (n = 30), AD (n = 11), and AR (n = 27) were included. Stratum corneum (SC) thickness, water, ceramides/fatty acids, and natural moisturizing factor (NMF) were measured by CRS along with transepidermal water loss and capacitance on the ventral forearm, thenar, and cheek. Sebum levels were additionally measured on the forearm and cheek. RESULTS: No differences between SS and NSS subjects were found regarding SC thickness, water, and NMF content, yet a trend towards lower ceramides/fatty acids was observed in the cheek. Compared to AD subjects, the SS group showed higher ceramides/fatty acid content in the forearm, whereas no differences emerged with AR. The correlation of macroscopic biophysical techniques and CRS was weak, yet CRS confirmed the well-known lower content of NMF and water, and thinner SC in subjects with filaggrin mutations. CONCLUSION: The skin barrier in SS is not impaired in terms of SC thickness, water, NMF, and ceramides/fatty acid content. The failure of biophysical techniques to follow alterations in the molecular composition of the skin barrier revealed by CRS emphasizes a strong need in sensitive and specific tools for in vivo skin barrier analysis.

Response of the Endothelium to the Epicutaneous Application of Leukotriene B4.

BACKGROUND: Vascular changes, both endothelial and functional, are crucial events in inflammatory responses. OBJECTIVES: To investigate the dynamics of endothelial cell (EC) and functional changes during acute inflammation in an in vivo model of the skin using leukotriene B4. METHODS: EC proliferation, vascular network size, vessel diameter (VD), and hypoxia-inducible factor (HIF)-1α were studied by immunohistochemical CD31/Ki67 double staining and single staining of HIF-1α. Cutaneous perfusion (CP) was assessed using the Twente Optical Perfusion Camera. RESULTS: The initial phase illustrated an increase in VD, Ki67+ EC, and HIF-1α expression and late-phase vascular expansion. The HIF-1α and Ki67+ EC expression was limited. CP and VD were augmented after 24 h. CONCLUSION: The early phase of inflammation is characterized by EC proliferation and HIF-1α expression. Vascular expansion continues over time. CP and VD are seen in both phases of inflammation. Angiogenesis, vascular network formation, and perfusion are time-dependent processes which are mutually related during inflammation.

Clinical, biophysical, immunohistochemical, and in vivo reflectance confocal microscopy evaluation of the response of subjects with sensitive skin to home-use fractional non-ablative photothermolysis device.

BACKGROUND: Fractional photothermolysis using professional devices is a well-accepted and a widely used technique for skin rejuvenation. Recently, the technology has also been implemented in devices for home-use. Yet, a subpopulation of consumers exists that reacts excessively to this stimulation and reports "sensitive skin" (SS). OBJECTIVE: The goal of this study was to evaluate the response of subjects with SS and NSS to fractional non-ablative photothermolysis to provide additional insights in the pathophysiology of SS. METHODS: Subjects with SS and non-sensitive skin (NSS), selected using a proprietary questionnaire were stimulated by applying a home-use fractional non-ablative photothermolysis device. Self-reported perceptions and objective effects were evaluated after 0.5, 8, 24, and 72 hours by clinical, biophysical and immunohistochemical assessment, and in vivo reflectance confocal microscopy (RCM). RESULTS: Significantly fewer mast cells were found in SS compared to NSS subjects, 0.5 and 72 hours after stimulus based on tryptase staining, and SS subjects report discomfort more frequently. Immunohistochemical biomarkers revealed new insights in the effects of fractional non-ablative photothermolysis, which were supported by RCM: peri- and interlesional epidermal proliferation, and changes in keratinocyte differentiation. CONCLUSION: Previously, we have already reported that SS could be elicited by mechanical and chemical stimuli. Thus, mild yet excessive self-reported perceptions described here supports the hypothesis about existence of generalized skin sensitivity. Furthermore, it supports a view point suggesting involvement of TRPV1 receptors in this phenomenon. While histological evaluation, in line with our previous results points to the role of mast cells in SS, overall, however, fractional non-ablative photothermolysis causes only mild damage, nearly equal in SS and NSS and could be used as an in vivo model for skin regeneration without manipulating the skin barrier. Lasers Surg. Med. 48:474-482, 2016. © 2016 Wiley Periodicals, Inc.

Balance of Treg versus T-effector cells during systemic treatment with adalimumab and topical treatment with calcipotriol-betamethasone dipropionate ointment.

Diminished suppressive capacity of regulatory T cells (Treg) has been demonstrated in blood and in lesional skin of psoriatic patients. Treatment with anti-TNFα restored the number and function of circulating Treg in psoriasis. We aimed to study Treg in the skin of psoriatic patients undergoing topical treatment with calcipotriol-betamethasone dipropionate (CBD) ointment (n = 12) or systemic treatment with anti-TNFα agent adalimumab (n = 10). Skin biopsies were collected from patients with chronic plaque psoriasis who responded to the above-mentioned treatments with a SUM-score improvement of at least 50% (at the end of treatment). Biopsies were processed for immunohistochemistry. As Treg function is associated with a numerical balance between Treg and effector T cells, Foxp3/CD4 ratios were calculated. It appeared that both treatments cause a significant decrease in the presence of Foxp3+ cells. However, in patients that were treated with CBD ointment, we observed lower Foxp3/CD4 ratios after 8 weeks of treatment compared to baseline (t = 0: 0.41 ± 0.08; t = 8: 0.22 ± 0.04, P = 0.033), whereas in patients who were treated with adalimumab we observed an increase of the Foxp3/CD4 ratios after 1.5 and 16 weeks of treatment compared to baseline (t = 0: 0.25 ± 0.04; t = 1.5: 0.32 ± 0.06; t = 16: 0.49 ± 0.10, P = 0.15). Based on Foxp3/CD4 ratios, we can conclude that adalimumab treated skin differs from CBD treated skin with regard to the anti-inflammatory/inflammatory balance. We suggest that, in contrast to CBD ointment, adalimumab favours local Treg function in the skin.