Biophysical Measurements and Ultrasonographic Findings in Chronic Dermatitis in Comparison with Uninvolved Skin

Photodegradation enhances the toxic effect of anthracene on skin

Anthracene, a polycyclic aromatic hydrocarbon (PAH), is a widespread environmental pollutant that poses potential risks to human health. Exposure to anthracene can result in various adverse health effects, including skin-related disorders. Photo exposure sufficiently removes the anthracene from the environment but also generates more degradation products which can be more toxic. The goal of this study was to assess the change in anthracene dermotoxicity caused by photodegradation and understand the mechanism of this change. In the present study, over 99.99% of anthracene was degraded within 24 h of sunlight exposure, while producing many intermediate products including 9,10-anthraquinone and phthalic acid. The anthracene products with different durations of photo exposure were applied to 2D and 3D human keratinocyte cultures. Although the non-degraded anthracene significantly delayed the cell migration, the cell viability and differentiation decreased dramatically in the presence of the photodegraded anthracene. Anthracene photodegradation products also altered the expression patterns of a number of inflammation-related genes in comparison to the control cells. Among these genes, il1a, il1b, il8, cxcl2, s100a9, and mmp1 were upregulated whereas the tlr4 and mmp3 were downregulated by the photodegraded anthracene. Topical deliveries of the photodegraded and non-degraded anthracene to the dorsal skin of hairless mice showed more toxic effects by the photodegraded anthracene. The 4-hour photodegradation products of anthracene thickened the epidermal layer, increased the dermal cellularity, and induced the upregulation of inflammatory markers, il1a, il1b, s100a9, and mmp1. In addition, it also prevented the production of a gap junction protein, Connexin-43. All the evidence suggested that photodegradation enhanced the toxicities of anthracene to the skin. The 4-hour photodegradation products of anthracene led to clinical signs similar to acute inflammatory skin diseases, such as atopic and contact dermatitis, eczema, and psoriasis. Therefore, the potential risk of skin irritation by anthracene should be also considered when an individual is exposed to PAHs, especially in environments with strong sunlight.

Ultra-High Frequency UltraSound (UHFUS) Assessment of Barrier Function in Moderate-to-Severe Atopic Dermatitis during Dupilumab Treatment

Atopic dermatitis (AD) is a chronic multifactorial inflammatory disease characterized by intense itching and inflammatory eczematous lesions. Biological disease-modifying drugs, such as dupilumab are recommended for patients with moderate-to-severe AD, refractory to systemic immunosuppressive therapies. Disease monitoring is performed by clinical scores. Since 1970, however, the use of ultrasound and particularly high-frequency ultrasound (HFUS), has identified alterations in dermal echogenicity, called the subepidermal low-echogenic band (SLEB), that correlates with disease severity and response to treatment. We enrolled 18 patients with moderate-to-severe AD, divided into two groups: twelve patients in the dupilumab treatment (Group A) and six patients in standard treatment, from February 2019 to November 2019. We performed ultra-high frequency ultrasound (UHFUS) evaluation of lesional and non-lesional skin, focusing on SLEB average thicknesses measurement, epidermal thickness, and vascular signal in correlation with objective disease scores (EASI, IGA), patient's reported scores (Sleep Quality NRS and Itch NRS), and TEWL and corneometry at baseline (T0), after 1 month (T1) and 2 months (T2). The SLEB average thickness measurement, vascular signal, and epidermal thickness showed a statistically significant reduction in lesional skin of the biological treatment group and no significant reduction in non-lesional skin in both groups. In the lesional skin of the standard treatment group, only epidermal thickness showed a statistically significant reduction. Our study demonstrates that SLEB measurement, vascular signals, and epidermal thickness could be used as objective parameters in monitoring the AD treatment response, while the presence of SLEB in non-lesional skin could be used as a marker of subclinical inflammation and could predict development of clinical lesions, suggesting a pro-active therapy. Further follow-up and research are needed to clarify the association of SLEB decrease/disappearance with a reduction of flares/prolongment of the disease remission time.

The Skin Microbiome in Cutaneous T-Cell Lymphomas (CTCL)—A Narrative Review

In recent years, numerous studies have shown a significant role of the skin microbiome in the development and exacerbation of skin diseases. Cutaneous T-cell lymphomas (CTCL) are a group of malignancies primary involving skin, with unclear pathogenesis and etiology. As external triggers appear to contribute to chronic skin inflammation and the malignant transformation of T-cells, some microorganisms or dysbiosis may be involved in these processes. Recently, studies analyzing the skin microbiome composition and diversity have been willingly conducted in CTCL patients. In this review, we summarize currently available data on the skin microbiome in CTLC. We refer to a healthy skin microbiome and the contribution of microorganisms in the pathogenesis and progression of other skin diseases, focusing on atopic dermatitis and its similarities to CTCL. Moreover, we present information about the possible role of identified microorganisms in CTCL development and progression. Additionally, we summarize information about the involvement of Staphylococcus aureus in CTCL pathogenesis. This article also presents therapeutic options used in CTCL and discusses how they may influence the microbiome.

Evaluation of tolerability and efficacy of a topical emulgel containing nanoliposomal ruxolitinib phosphate in the treatment of mild atopic dermatitis: A before-after single group pilot study

BACKGROUND

Ruxolitinib is a JAK1/2 inhibitor, which inhibits the signal transduction of interferon-gamma, a cytokine implicated in the pathogenesis of atopic dermatitis (AD). In this before-after single group phase IIA pilot study, we investigated the efficacy of topical nanoliposomal ruxolitinib phosphate (RuxoLip) emulgel in mild AD.

METHODS

Clinical evaluation was conducted on 10 patients with mild AD. The efficacy of the product as well as patient satisfaction were evaluated by local Scoring Atopic Dermatitis (SCORAD) of AD. In addition, trans-epidermal water loss (TEWL), stratum corneum (SC) hydration, sebum, erythema, melanin content and ultrasonographic parameters were measured before, and two and four weeks after treatment.

RESULTS

Four weeks of treatment reduced SCORAD, itching, and burning (P = 0.001, 0.001, and 0.001, respectively) and increased hydration, sebum, and epidermal density (P = 0.001, 0.018, and 0.037, respectively). SCORAD and other skin biophysical parameters improved within two weeks of treatment and then were in plateau for up to four weeks.

CONCLUSION

The topical ruxolitinib emulgel has good short-term efficacy and tolerability.

Biophysical and ultrasonographic changes of acute Old World cutaneous leishmaniasis skin lesions in comparison with uninvolved skin: A possible tool for non-invasive early detection and treatment outcome assessment

BACKGROUND

Cutaneous leishmaniasis (CL) is a skin disease caused by intracellular protozoa, which is endemic in Iran. The goal of this study was to compare biophysical characteristics in CL lesions with uninvolved skin.

METHODS

Stratum corneum hydration, transepidermal water loss, surface friction, pH, sebum, melanin, erythema, temperature, elasticity parameters (R0, R2, and R5), thickness and echo-density of epidermis and dermis were measured on the active erythematous indurated part of a typical CL lesion in 20 patients, and compared with the same location on the other side of the body as control. Paired t- test was used for statistical analyses and a P<0.05 was considered significant.

RESULTS

Melanin content, R2 and echo-density of dermis were significantly lower, whereas transepidermal water loss, friction index, pH, erythema index, temperature and the thickness of dermis were significantly higher in CL lesions. There was no significant difference in stratum corneum hydration, sebum, R0, R5, thickness of epidermis and density of epidermis between CL and normal skin.

CONCLUSIONS

CL lesions are characterized by certain changes in biophysical and ultrasonographic properties, which are mostly correlated with histological features. These changes are likely to be useful in the non-invasive early detection of CL and also as treatment outcome measures for clinical trials of new treatment modalities for CL in the future. This article is protected by copyright. All rights reserved.

Epidermal thickness in healthy humans: A systematic review and meta-analysis

Several skin diseases are characterised by epidermal alterations affecting epidermal thickness. Reference values of epidermal thickness in healthy humans and knowledge of possible differences regarding age, sex, skin phototype, and ethnic origin are essential in research and in clinical practice. The objectives of this systematic review were to provide epidermal thickness reference values for healthy human skin and describe possible effects of measurement methods, age, sex, ethnic origin, and skin phototype. A combined search in the databases Medline and Embase, and other sources was conducted. Searches covered a period from 1946 to 3^rd June 2020. Included studies were primary observational and interventional studies providing means and spread values of epidermal thickness estimates in healthy humans, with clear reporting of skin area, age and measurement method, and optional reporting of sex, ethnic origin and skin phototype. Data were extracted per skin area and pooled in random-effects models. 142 studies were included in the qualitative synthesis and 133 in the meta-analysis. Pooled epidermal thickness estimates were calculated for 37 skin areas. The lowest epidermal thickness of 31.2 (95% CI 27.8 to 34.6) μm was reported for the penis, and the highest of 596.6 (95% CI 443.9 to 749.3) μm for the plantar aspect of the foot. Differences of epidermal thickness estimates obtained by histology, optical coherence tomography and laser scanning microscopy were minor. High-frequency ultrasonography produces systematically higher values. Epidermis was thinner in aged skin. Differences between sexes and among ethnic origins where minor. Epidermal thickness reference values are provided for 37 skin areas. In conclusion, the epidermis tends to become thinner by ageing and does not seem to be influenced by sex. Histology, optical coherence tomography and laser scanning microscopy might be used interchangeably to measure epidermal thickness, whereas high-frequency ultrasound should not be used.

Epidermal Barrier Function and Skin Homeostasis in Atopic Dermatitis: The Impact of Age

Skin is damaged in atopic dermatitis (AD) patients. Age is also believed to have a negative effect on epidermal barrier function. The aim of this study was to investigate skin barrier function changes with age in AD patients. A cross-sectional study was conducted including 162 participants, 81 AD patients and 81 healthy volunteers. Skin barrier function parameters, such as transepidermal water loss (TEWL), erythema, temperature, stratum corneum hydration (SCH), pH, and elasticity, were evaluated. Healthy volunteers were evaluated on the volar forearm. AD patients were measured on two regions: on an eczematous lesion on the volar forearm and on a non-involved area 5 cm from the affected area. TEWL was lower on healthy skin than uninvolved AD skin (9.98 vs. 25.51 g·m⁻²·h⁻¹, p < 0.001) and AD eczematous lesions (9.98 vs. 28.38 g·m⁻²·h⁻¹, p < 0.001). SCH was lower on AD eczematous lesions than uninvolved AD skin (24.23 vs. 39.36 AU, p < 0.001) and healthy skin (24.23 vs. 44.36 AU, p < 0.001). Elasticity was lower on AD eczematous lesions than uninvolved AD skin (0.69 vs. 0.74, p = 0.038) and healthy skin (0.69 vs. 0.77, p = 0.014). A negative correlation was found between age and elasticity in all the population (r = −0.383, p < 0.001). This correlation was stronger in AD patients (r = −0.494, p < 0.001) than in controls (r = −0.266, p = 0.092). After conducting a linear regression model in AD patients adjusted by age, sex, and SCORing Atopic Dermatitis (SCORAD), it was found that elasticity was impaired by an increasing age (β = −0.004, p < 0.001) and a higher SCORAD (β = −0.003, p < 0.001). The skin barrier function is impaired by age and AD, reflected mainly in poor elasticity values in older AD patients.

Peroxisomal Fatty Acid Oxidation and Glycolysis Are Triggered in Mouse Models of Lesional Atopic Dermatitis

Alterations of the lipid profile of the stratum corneum have an important role in the pathogenesis of atopic dermatitis (AD) because they contribute to epidermal barrier impairment. However, they have not previously been envisioned as a cellular response to altered metabolic requirements in AD epidermis. In this study, we report that the lipid composition in the epidermis of flaky tail, that is, ft/ft mice mimics that of human lesional AD (ADL) epidermis, both showing a shift toward shorter lipid species. The amounts of C24 and C26 free fatty acids and C24 and C26 ceramides-oxidized exclusively in peroxisomes-were reduced in the epidermis of ft/ft mice despite increased lipid synthesis, similar to that seen in human ADL edpidermis. Increased ACOX1 protein and activity in granular keratinocytes of ft/ft epidermis, altered lipid profile in human epidermal equivalents overexpressing ACOX1, and increased ACOX1 immunostaining in skin biopsies from patients with ADL suggest that peroxisomal β-oxidation significantly contributes to lipid signature in ADL epidermis. Moreover, we show that increased anaerobic glycolysis in ft/ft mouse epidermis is essential for keratinocyte proliferation and adenosine triphosphate synthesis but does not contribute to local inflammation. Thus, this work evidenced a metabolic shift toward enhanced peroxisomal β-oxidation and anaerobic glycolysis in ADL epidermis.

Biophysical and ultrasonographic changes in pityriasis rosea compared with uninvolved skin

BACKGROUND

Pityriasis rosea (PR) is a common, self-limited, inflammatory papulosquamous skin disease with a possible viral etiology.

OBJECTIVE

The goal of this study was to evaluate skin biophysical properties in patients with PR compared with uninvolved skin to better understand the pathogenesis of PR.

METHODS

Stratum corneum hydration, transepidermal water loss, surface friction, pH, sebum, melanin, erythema, temperature, elasticity parameters (R0, R2, R5), thickness, and echodensity of the epidermis and dermis were measured on lesions of classic PR in 21 patients and compared with control sites (average of uninvolved perilesional and symmetrical skin) with a paired t test.

RESULTS

Stratum corneum hydration (p < .001), R0 (p = .003), R2 (p = .001), R5 (p = .003), and echodensity of the dermis (p = .006) were significantly lower, whereas transepidermal water loss (p = .001), pH (p < .001), and erythema (p < .001) were significantly higher in PR lesions. There was no significant difference in friction index, sebum, melanin content, temperature, thickness of the epidermis and dermis, and echodensity of the epidermis between PR and normal skin.

CONCLUSION

PR skin is characterized by certain alterations in biophysical properties, which are mostly correlated with histologic changes. These changes may be helpful in early, noninvasive diagnosis of PR.

Biophysical and ultrasonographic changes in early patch/plaque stage of mycosis fungoides, compared with uninvolved skin

BACKGROUND

The goal of this study was evaluation of the skin biophysical properties in early patch/plaque stage of mycosis fungoides (MF) and its comparison with uninvolved skin in order to gain a better understanding of the pathogenesis of diseases.

MATERIALS AND METHODS

The stratum corneum hydration, transepidermal water loss (TEWL), surface friction, pH, sebum, melanin, erythema, temperature, elasticity parameters (R0, R2, R5), thickness, and echo density of epidermis and dermis were measured on lesions of 21 patients and compared with controls (average measures of uninvolved perilesional and symmetrical skins) by paired sample t test.

RESULTS

Stratum corneum hydration (P < 0.001) and echo density of dermis (P = 0.044) were significantly lower, whereas pH (P-value = 0.007), erythema (P < 0.001), and melanin content (P = 0.007) were significantly higher in lesions. There was not any significant difference in TEWL, friction index, sebum, temperature, R0, R2, R5, thickness of epidermis and dermis, and echo density of epidermis between lesions and normal skin.

CONCLUSION

Parapsoriasis/MF lesions are specified by a set of certain changes in biophysical properties which are mainly correlated with histological changes. These sets of alterations may help in noninvasive, early diagnosis of parapsoriasis/MF.

High-Frequency Ultrasonography-Possibilities and Perspectives of the Use of 20 MHz in Teledermatology

High-frequency ultrasonography (HF-USG) is a non-invasive and in vivo method of visualization of the skin and upper part of subcutaneous tissue based on ultrasounds above 20 MHz. Although initially HF-USG was introduced to measure skin thickness, it currently gained widespread acceptance in dermato-oncology, primarily when used to determine skin tumor margins. Moreover, its application in different dermatology fields is known, particularly as a rapidly evolving method in the objective evaluation of the severity of various chronic skin diseases. Among different specialties, teledermatology belongs to leading and continually developing areas of successful telemedicine applications. Various skin conditions are visible to the human eye, which makes them particularly suitable for telemedicine. However, HF-USG enables specialists to look into deeper skin layers, thus extending diagnostic options. On the other hand, teledermatology creates the possibility of sending images for consultation and facilitates the therapeutic decision as HF-USG can be used in an asynchronous store and forward manner. It seems that HF-USG and teledermatology may be regarded as a truly matched pair. The aim of this work is to present current applications of 20-MHz ultrasonography in dermatology, including skin neoplasms and chronic skin diseases. Moreover, the authors aimed to analyze the possibilities of HF-USG use as a valuable tool in teledermatology, especially in diagnosing and monitoring patients suffering from long-lasting skin conditions.

Skin Barrier Function in Psoriasis and Atopic Dermatitis: Transepidermal Water Loss and Temperature as Useful Tools to Assess Disease Severity

Multiple diagnostic tools are used to evaluate psoriasis and atopic dermatitis (AD) severity, but most of them are based on subjective components. Transepidermal water loss (TEWL) and temperature are skin barrier function parameters that can be objectively measured and could help clinicians to evaluate disease severity accurately. Thus, the aims of this study are: (1) to compare skin barrier function between healthy skin, psoriatic skin and AD skin; and (2) to assess if skin barrier function parameters could predict disease severity. A cross-sectional study was designed, and epidermal barrier function parameters were measured. The study included 314 participants: 157 healthy individuals, 92 psoriatic patients, and 65 atopic dermatitis patients. TEWL was significantly higher, while stratum corneum hydration (SCH) (8.71 vs. 38.43 vs. 44.39 Arbitrary Units (AU)) was lower at psoriatic plaques than at uninvolved psoriatic skin and healthy controls. Patients with both TEWL > 13.85 g·m⁻²h⁻¹ and temperature > 30.85 °C presented a moderate/severe psoriasis (psoriasis area severity index (PASI) ≥ 7), with a specificity of 76.3%. TEWL (28.68 vs. 13.15 vs. 11.60 g·m⁻² h⁻¹) and temperature were significantly higher, while SCH (25.20 vs. 40.95 vs. 50.73 AU) was lower at AD eczematous lesions than uninvolved AD skin and healthy controls. Patients with a temperature > 31.75 °C presented a moderate/severe AD (SCORing Atopic Dermatitis (SCORAD) ≥ 37) with a sensitivity of 81.8%. In conclusion, temperature and TEWL values may help clinicians to determine disease severity and select patients who need intensive treatment.

The value of high-frequency ultrasonography in the differential diagnosis of early mycosis fungoides and inflammatory skin diseases: A case-control study

BACKGROUND

The clinical manifestations of early mycosis fungoides (eMF) are non-specific and similar to inflammatory skin diseases. High-frequency ultrasonography (HF-US) can show small structure of skin lesions and is helpful to provide information objectively.

MATERIALS AND METHODS

A case-control study was designed in 62 patients with multiple erythemas and scales, including 18 eMF and 44 age-matched patients with eczema (EC) or psoriasis vulgaris (PsV). The most significant lesions were collected by 50 MHz HF-US. The assessment of ultrasound included epidermal morphology and thickness, infiltration depth, subepidermal low echogenic band (SLEB) boundary and thickness, internal echo, and number of linear acoustic shadows (LAS) behind the epidermis. The ultrasonic characteristics of eMF, EC, and PsV lesions were analyzed.

RESULTS

Epidermal thickness (P < .001, sensitivity 88.9%, specificity 75.0%) and SLEB thickness (P = 0.006, sensitivity 55.6%, specificity 90.9%) were useful for differential diagnosis of eMF and PsV/EC. When eMF was diagnosed by epidermal thickness < 0.2375 mm, the AUC was 0.845, which had the highest diagnostic efficacy among all ultrasound signs. In addition, compared with eMF and EC, the LAS number of PsV lesions was the highest and statistically significant.

CONCLUSION

The results showed that HF-US could provide some extra information in identification of eMF, EC, and PsV and has potential clinical value.

Innate Antimicrobial Defense of Skin and Oral Mucosa

This special issue intends to review and update our understanding of the antimicrobial defense mechanisms of the skin and oral cavity. These two environments are quite different in terms of water, pH, and nutrient availability, but have some common antimicrobial factors. The skin surface supports the growth of a limited range of microorganisms but provides a hostile environment for others. The growth of most microorganisms is prevented or limited by the low pH, scarcity of some nutrients such as phosphorus and the presence of antimicrobial peptides, including defensins and cathelicidins, and antimicrobial lipids, including certain fatty acids and long-chain bases. On the other hand, the oral cavity is a warm, moist, nutrient rich environment which supports the growth of diverse microflora. Saliva coating the oral soft and hard surfaces determines which microorganisms can adhere to these surfaces. Some salivary proteins bind to bacteria and prevent their attachment to surfaces. Other salivary peptides, including defensins, cathelicidins, and histatins are antimicrobial. Antimicrobial salivary proteins include lysozyme, lactoferrin, and lactoperoxidase. There are also antimicrobial fatty acids derived from salivary triglycerides and long-chain bases derived from oral epithelial sphingolipids. The various antimicrobial factors determine the microbiomes of the skin surface and the oral cavity. Alterations of these factors can result in colonization by opportunistic pathogens, and this may lead to infection. Neutrophils and lymphocytes in the connective tissue of skin and mucosa also contribute to innate immunity.