Clearing of psoriasis documented by laser Doppler perfusion imaging contrasts remaining elevation of dermal expression levels of CD31

Assessment of Psoriatic Skin Features Using Non-Invasive Imaging Technique

Background: Psoriasis is one of the most commonly recognized dermatological diseases, characterized by distinct structural changes, hyperproliferation and inflammation. The aim of the study was quantitative comparisons of psoriatic skin with skin without psoriatic lesions by non-invasive imaging methods. Methods: 71 patients diagnosed with psoriasis vulgaris underwent non-invasive imaging of skin at the site of the psoriatic lesion and at the site without such lesion. Skin density, epidermis thickness and subepidermal low-echogenic band (SLEB) thickness were measured by high-resolution ultrasound (HFU). Blood perfusion was assessed using laser speckle contrast analysis (LASCA) and skin temperature was measured by thermal imaging camera. Hyperspectral camera was used to obtain spectral reflectance profiles in psoriatic lesion and skin without psoriatic changes. Results: The greatest differences in skin density and epidermal thickness between psoriatic and unchanged skin were observed on the forearms. The skin covered with psoriatic plaques was 80% less dense, and the epidermis in this area was 121% thicker. The greatest thickness of SLEB was observed in the knee area (Me = 0.389 mm). Skin with psoriatic lesions is characterized by a higher temperature (Me = 33.6 vs. Me = 31) and blood perfusion than skin without psoriasis (Me = 98.76 vs. Me = 50.65). Skin without psoriasis shows lower reflectance than psoriatic lesion from 623 nm to 1000 nm; below this value, skin without psoriatic lesion shows higher reflectance. Conclusions: Skin density and epidermis thickness, skin blood perfusion, temperature and reflectance can be useful parameters for monitoring the course of psoriasis and its treatment, especially since the examination of psoriatic skin with proposed methods is non-invasive, quantitative and easy to perform in clinical conditions.

Detection of microvascular changes in systemic sclerosis and other rheumatic diseases

Morphological and functional analysis of the microcirculation are objective outcome measures that are recommended for use in the presence of clinical signs of altered peripheral blood flow (such as Raynaud phenomenon), which can occur in systemic sclerosis (SSc) and other autoimmune rheumatic diseases. Several advanced non-invasive tools are available for monitoring the microcirculation, including nailfold videocapillaroscopy, which is the best-studied and most commonly used method for distinguishing and quantifying microvascular morphological alterations in SSc. Nailfold videocapillaroscopy can also be used alongside laser Doppler techniques to assist in the early diagnosis and follow-up of patients with dermatomyositis or mixed connective tissue disease. Power Doppler ultrasonography, which has been used for many years to evaluate the vascularity of synovial tissue in rheumatoid arthritis, is another promising tool for the analysis of skin and nailbed capillary perfusion in other autoimmune rheumatic diseases. Other emerging methods include raster-scanning optoacoustic mesoscopy, which offers non-invasive high-resolution 3D visualization of capillaries and has been tested in psoriatic arthritis and SSc. The principle functions and operative characteristics of several non-invasive tools for analysing microvascular changes are outlined in this Review, and the clinical roles of validated or tested imaging methods are discussed for autoimmune rheumatic diseases.

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.

Handheld versus mounted laser speckle contrast perfusion imaging demonstrated in psoriasis lesions

Enabling handheld perfusion imaging would drastically improve the feasibility of perfusion imaging in clinical practice. Therefore, we examine the performance of handheld laser speckle contrast imaging (LSCI) measurements compared to mounted measurements, demonstrated in psoriatic skin. A pipeline is introduced to process, analyze and compare data of 11 measurement pairs (mounted-handheld LSCI modes) operated on 5 patients and various skin locations. The on-surface speeds (i.e. speed of light beam movements on the surface) are quantified employing mean separation (MS) segmentation and enhanced correlation coefficient maximization (ECC). The average on-surface speeds are found to be 8.5 times greater in handheld mode compared to mounted mode. Frame alignment sharpens temporally averaged perfusion maps, especially in the handheld case. The results show that after proper post-processing, the handheld measurements are in agreement with the corresponding mounted measurements on a visual basis. The absolute movement-induced difference between mounted-handheld pairs after the background correction is [Formula: see text] (mean ± std, [Formula: see text]), with an absolute median difference of [Formula: see text]. Realization of handheld LSCI facilitates measurements on a wide range of skin areas bringing more convenience for both patients and medical staff.

Validity and sensitivity to change of laser Doppler imaging as a novel objective outcome measure for cutaneous lupus erythematosus

OBJECTIVES

The objectives of this study were to assess the reliability of a novel objective outcome measure, laser Doppler imaging (LDI), its validity against skin biopsy histology and other clinical instruments, including localized cutaneous lupus disease area and severity index (L-CLASI) and visual analogue scale (VAS) score of photographs, and its responsiveness to clinical change with therapy.

METHODS

A prospective observational cohort study was conducted in 30 patients with active cutaneous lupus erythematosus (CLE). At baseline and 3 months, disease activity was assessed using L-CLASI and a high resolution LDI system by two assessors. Skin biopsy was scored as 0 = non-active, 1 = mild activity and 2 = active. Photographs were assessed by two clinicians using 100 mm VAS. Inter-rater reliability was analyzed using Bland-Altman limits of agreement. Correlation between histology and LDI, L-CLASI and VAS and sensitivity to change of LDI with physician subjective assessment of change (PSAC) at 3 months were analyzed using Kendall's tau-a.

RESULTS

Of 30 patients with CLE, 28 (93%) were female, mean (SD) age 48.4 (11.5) y, 25 (83%) were Caucasians, 25 (83%) had concurrent systemic lupus erythematosus and 16 (53%) were smokers. CLE subtypes were acute = 9, subacute = 8 and chronic = 13. Inter-rater agreement for LDI was fair but for VAS score of photographs was poor. In 20 patients with biopsy, correlation with histology was better for LDI (tau-a = 0.53) than L-CLASI (tau-a = 0.26) (difference = 0.27; 90% CI 0.05-0.49) or VAS score of photographs (tau-a = 0.17) (difference = 0.36; 90% CI 0.04-0.68). There was a moderate correlation between PSAC score and change in LDI (tau-a = 0.56; 90% CI 0.38-0.74; p < 0.001, n = 15).

CONCLUSION

LDI provides a reliable, valid and responsive quantitative measure of inflammation in CLE. It has a better correlation with histology compared to clinical instruments. LDI provides an objective outcome measure for clinical trials.

The dynamics of endothelial changes in vivo following standardized skin injury

BACKGROUND

Vascular changes, that is, functional and cellular endothelial changes, are of essential importance in healing. Alongside these vascular changes, inflammatory factors and hypoxia may play an important role in recovery.

OBJECTIVES

To investigate the dynamics of functional and cellular endothelial changes and hypoxia in vivo following standardized skin damage caused by tape stripping.

METHODS

Vascular changes (endothelial cell proliferation, vascular network size, vessel diameter) and hypoxia-inducible factor-1α were examined immunohistochemically using a CD31/Ki67 double staining and HIF-1α single staining. Cutaneous perfusion was evaluated using the Twente Optical Perfusion Camera (TOPCam).

RESULTS

The initial phase is seen to be dominated by endothelial cell proliferation, HIF-1α expression, and vasodilatation. Cutaneous perfusion intensity is particularly increased in the first 16 hours. The late phase of recovery (after 72 hours) is characterized by a peak of expansion of the vascular network and a second peak of endothelial cell proliferation and HIF-1α expression.

CONCLUSION

Endothelial cell proliferation and HIF-1α expression appear to be (strongly) related, having maximum levels at 16 hours and 72 hours. Angiogenesis and HIF-1α expression are not continuous processes, but rather occur intermittently.

Treatment of Rosacea using acupuncture for improving the local skin microcirculation: A case report

RATIONALE

Rosacea is an irritating disease that affects patients' health and life quality. The current treatments for rosacea have limited efficacy and are generally not satisfying most patients. This report presents a patient diagnosed with rosacea who was treated with acupuncture to a satisfactory effect. Laser Doppler was used to measure the local blood perfusion of the nose before, during, and after acupuncture treatment. The Dermatology Life Quality Index (DLQI) was used to measure the impact of rosacea on the quality of the patient's life.

PATIENT CONCERNS

A 52-year-old woman had been diagnosed with rosacea 18 months before this study. She had tried medical treatments in other hospitals with metronidazole cream, antifungal drugs, and steroidal ointments, but the effect was poor and limited.

DIAGNOSES

In this study, the diagnosis of rosacea (stage I, subtype Erythematotelangiectatic) was made by a dermatologist according to physical examination).

INTERVENTIONS

The patient's treatment included a half-hour of acupuncture 3 times per week.

OUTCOMES

The patient experienced significant improvements in the region around the nose after 3 sessions of acupuncture treatment within the first week and reported that there was no relapse for 6 months after acupuncture treatment. The perfusion of blood flow was redistributed during and after acupuncture treatment according to laser Doppler measurements. The patient's DLQI score substantially improved. The patient was generally satisfied with the acupuncture treatment.

LESSONS

The results suggested that acupuncture might be an alternative therapy for facial localized rosacea. As well, acupuncture may be effective in treating rosacea through redistributing micro-circulation of blood at the localized area of effect. The overall costs of the rosacea treatment may be reduced, provided that this therapy is demonstrated to be effective in future controlled studies.

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.

Skin-penetrating polymeric nanoparticles incorporated in silk fibroin hydrogel for topical delivery of curcumin to improve its therapeutic effect on psoriasis mouse model

A poor percutaneous penetration capability for most topical anti-inflammatory drugs is one of the main causes compromising their therapeutic effects on psoriatic skin. Even though curcumin has shown a remarkable efficacy in the treatment of psoriasis, its effective penetration through the stratum corneum is still a major challenge during transdermal delivery. The aim of our study was to design skin-permeating nanoparticles (NPs) to facilitate delivery of curcumin to the deeper layers of the skin. A novel amphiphilic polymer, RRR-α-tocopheryl succinate-grafted-ε-polylysine conjugate (VES-g-ε-PLL) was synthesized and self-assembled into polymeric nanoparticles. The nanoparticles of VES-g-ε-PLL exhibiting an ultra-small hydrodynamic diameter (24.4nm) and a positive Zeta potential (19.6mV) provided a strong skin-penetrating ability in vivo. Moreover, curcumin could effectively be encapsulated in the polymeric nanoparticles with a drug loading capacity of 3.49% and an encapsulating efficiency of 78.45%. In order to prolong the retention time of the ultra-small curcumin-loaded nanoparticles (CUR-NPs) in the skin, silk fibroin was used as a hydrogel-based matrix to further facilitate topical delivery of the model drug. In vitro studies showed that CUR-NPs incorporated in silk fibroin hydrogel (CUR-NPs-gel) exhibited a slower release profile of curcumin than the plain CUR-gel, without compromising the skin penetration ability of CUR-NPs. In vivo studies on miquimod-induced psoriatic mice showed that CUR-NPs-gel exhibited a higher therapeutic effect than CUR-NPs as the former demonstrated a more powerful skin-permeating capability and a more effective anti-keratinization process. CUR-NPs-gel was therefore able to inhibit the expression of inflammatory cytokines (TNF-α, NF-κB and IL-6) to a greater extent. In conclusion, the permeable nanoparticle-gel system may be a potential carrier for the topical delivery of lipophilic anti-psoriatic drugs.