Inflammation Causes Exacerbation of COVID-19: How about Skin Inflammation?

COVID-19 is a recently emerged viral infection worldwide. SARS-CoV-2, the causative virus, is believed to have emerged from bat coronaviruses, probably through host conversion. The bat coronavirus which has the highest gene homology to SARS-CoV-2 specifically infects deep forest bats in China whose habitat extends through the Middle East to Southern Europe. Host conversion might have occurred due to the deforestation by humans exposing wild bats to the environment they had never encountered before. SARS-CoV-2 infects cells through two mechanisms: through its receptor ACE2 with the help of enzyme TMPRSS and through membrane fusion with the help of elastases in the inflammatory condition. Obesity, hypertension, diabetes mellitus, and pulmonary diseases cause poor prognosis of COVID-19. Aging is another factor promoting poor prognosis. These diseases and aging cause low-level and persistent inflammation in humans, which can promote poor prognosis of COVID-19. Psoriasis and atopic dermatitis are the major inflammatory skin diseases. These inflammatory skin conditions, however, do not seem to cause poor prognosis for COVID-19 based on the epidemiological data accumulated so far. These mechanisms need to be elucidated.     

18β‐Glycyrrhetinic acid: its core biological properties and dermatological applications

Recently, attention has been focused on identifying natural herbal compounds with high biological activity, especially antioxidative, anti‐inflammatory and antimicrobial properties, for preventing and controlling various skin conditions, including inflammation‐related diseases such as atopic dermatitis and UV‐induced skin photoaging. One key active plant ingredient is 18β‐glycyrrhetinic acid (GA), the main metabolite of glycyrrhizin (GL), obtained from licorice root. The review examines the valuable biological properties of GA, particularly those playing key roles in the treatment of various dermatological disorders in humans. The review highlights the key anti‐inflammatory, antioxidant and antimicrobial properties of GA and its toxicity towards normal cells lines. It also examines the physicochemical properties of GA and presents methods of increasing its penetration through the stratum corneum and bioaccumulation with the use of modern delivery systems such as liposomes and nanoemulsions.     

Comparative Analysis of the Microbiome across the Gut–Skin Axis in Atopic Dermatitis

Atopic dermatitis (AD) is a refractory and relapsing skin disease with a complex and multifactorial etiology. Various congenital malformations and environmental factors are thought to be involved in the onset of the disease. The etiology of the disease has been investigated, with respect to clinical skin symptoms and systemic immune response factors. A gut microbiome–mediated connection between emotional disorders such as depression and anxiety, and dermatologic conditions such as acne, based on the comorbidities of these two seemingly unrelated disorders, has long been hypothesized. Many aspects of this gut–brain–skin integration theory have recently been revalidated to identify treatment options for AD with the recent advances in metagenomic analysis involving powerful sequencing techniques and bioinformatics that overcome the need for isolation and cultivation of individual microbial strains from the skin or gut. Comparative analysis of microbial clusters across the gut–skin axis can provide new information regarding AD research. Herein, we provide a historical perspective on the modern investigation and clinical implications of gut–skin connections in AD in terms of the integration between the two microbial clusters.     

Relationship between the average projected area of corneocytes and the onset age of atopic dermatitis in childhood

In childhood, atopic dermatitis typically begins around 2--6 months of age. It is thought that the skin barrier dysfunction as well as allergic disease is important in the mechanism of atopic dermatitis. However, there are few reports of the skin barrier function in childhood. So we examined the relationship between the longitudinal surveys of the skin barrier function through the average projected area of corneocytes (APAc) and clinical findings in children from 1 to 12 months. As a result of examinations, APAc of cheek and upper arm in 1-month-old children is the same as those in adults, and APAc of cheek and upper arm decreases by 6 months of age. These results suggest that the skin barrier function decreases before or after the onset age of atopic dermatitis during childhood. Moreover, we examined APAc of children aged 0–5 for 1 year in the same nursery. APAc of upper arm in atopic dermatitis or atopic disposition has a significant difference compared with that of the other subjects in December. Furthermore, it was shown that change of APAc in the children under medical treatment was correlated with clinical findings. In conclusion, it was thought that the APAc shown as the index of skin barrier dysfunction is associated with the onset age of atopic dermatitis in childhood.     

Sensitivity to perfumes and preservatives in patients with contact dermatitis

Patients with contact dermatitis were patch tested for sensitivity to perfumes (perfume mixture, balsam of Peru) and to preservatives (formaldehyde). The percentages of sensitivity in Greek patients with contact dermatitis were 8.1% for the perfume mixture, 3.7% for the balsam of Peru and 2.3% for formaldehyde. It is notable that 1.4% of the patients demonstrated simultaneous sensitivity to the perfume mixture and to balsam of Peru, while no case of simultaneous sensitivity occurred for formaldehyde and the two other compounds. Factors such as sex, age, occupation and anatomic site of the appearance of dermatitis in patients were taken into account and related to the percentages of sensitivity.
Comparing with the literature we have concluded that the frequency of appearance of sensitivity by Greek patients is not significantly different from the average observed for patients in Northern or Southern Europe.     

Azuki bean (Vigna angularis) extract inhibits the development of experimentally induced atopic dermatitis-like skin lesions in NC/Nga mice

The present study investigated the effects of azuki bean (Vigna angularis) extract (VAE) on the progress of atopic dermatitis (AD)-like skin lesions in NC/Nga mice induced by 1-chloro-2,4-dinitrobenzene. The efficacy of VAE in NC/Nga mice was determined by measuring gross and histological skin lesions, serum IgE levels, eosinophil ratio in peripheral leucocytes, and mRNA expression levels of interleukin (IL)-4, tumour necrosis factor (TNF)-α and interferon (IFN)-γ in splenocytes. Continuous ingestion of VAE inhibited the development of the AD-like skin lesions in a dose-dependent manner. In the VAE-treated mice, the numbers of mast cells in the skin, eosinophil ratio in peripheral leucocytes, relative mRNA expression of inflammatory cytokines in the spleen, and serum IgE levels were significantly reduced. Results suggest that VAE can inhibit the development of AD-like skin lesions in NC/Nga mice by regulating immune mediators and cells, and may be an effective alternative therapy for AD.     

Prevention of nickel release from electroplated articles in the context of allergic contact dermatitis: further outcomes

‘Nickel Allergy’ sometimes occurs when nickel-containing articles are in direct and prolonged contact with the skin, leading to corrosion of elemental nickel by sweat, liberating sufficient nickel ions to be absorbed through the skin and initiate an allergenic effect. EU ‘Nickel Restrictions’ impose limits on the amount of nickel released from articles intended for use in this application but permits a non-nickel surface coating that can ensure the rate of nickel release does not exceed 0.5?μg?cm^?2?week^?1 after 2 years of normal use. The official tests for coated items are simulated wear and corrosion under EN 12472 followed by determination of nickel release under EN 1811, and articles shall not be placed on the market unless they pass these tests. A paper published in Transactions during 2015 reported bright nickel coatings with top coats that would prevent nickel release and pass these tests. Regular chromium deposited from a hexavalent electrolyte was the benchmark, with microporous chromium and supplementary organic coatings evaluated for improved performance. All prevented nickel release, but the best low-cost commercial coating was regular (conventional) chromium deposited from a hexavalent electrolyte. Further tests reported here were conducted to evaluate bright nickel deposits with top coats of tin–cobalt alloy, and of hexavalent chromium with supplementary coatings of coloured physical vapour deposition and electrophoretic coatings. Tests with trivalent chromium top coats deposited from proprietary chloride and sulphate electrolytes showed that regular (conventional) chromium over bright nickel failed the nickel release test. But microporous trivalent chromium deposits passed the tests satisfactorily.     

Water-soluble chitosan and herbal honey compound alleviates atopic dermatitis-like lesions in NC/Nga mice

Atopic dermatitis (AD) is a chronic inflammatory skin disease that was influenced by complex interactions via genetic, environmental, immunologic, and biochemical factors, though the cause of AD is still unknown. It characterized by elevated serum immunoglobulin E (IgE) levels, immunological abnormalities, and eosinophilia in the tissues and peripheral blood. In the present study, we applied an antimicrobial moisturizing cream containing low-molecular weight water-soluble chitosan and herbal honey (AMCH) to remedy AD-like lesions. The inhibiting effect of AMCH on NC/Nga mice, that AD-like lesion was induced by 1-chloro-2,4-dinitrobenzene (DNCB), was evaluated by examining sensory evaluation scores, scratching behavior, immune cells in blood, serum IgE level, infiltration of mast cells, and skin histology. The total sensory evaluation scores, scratching behavior, the level of serum IgE, interlukin-4 (IL-4), and IL-12 in AD mouse model were significantly reduced by AMCH. Moreover, its suppressing effect resulted in decreased mast cell infiltration. Our results suggest that AMCH might be beneficial as a potent agent for treatment of AD-like lesion.     

Effects of dietary glucosylceramide on dermatitis in atopic dermatitis model mice

The effects of dietary plant and yeast cerebroside (glucosylceramide), a major sphingolipid in plants and yeast, on atopic dermatitis (AD) like symptoms were investigated in a mouse model. After 7 wk of feeding with a diet containing maize glucosylceramide, plasma IgE levels became significantly lower and in contrast, the levels of interleukin (IL)‐12, which induces cellular immunity, became significantly higher in the AD mice than in the controls. However, the sphingolipid constituents of the skin fraction in the maize glucosylceramide fed group did not contain sphingoid bases of plant origin, such as 8‐unsaturated sphingoid bases. The results of the present study indicated that dietary plant glucosylceramide prevented AD‐like symptoms in AD model mice via regulation of Th1/Th2 balance. Practical applications: Dietary plant and yeast glucosylceramides have been shown to suppress AD‐like symptoms in AD model mice via regulation of helper T‐cell Th1/Th2 balance. Glucosylceramide are capable of preventing AD and may be useful in skincare products.     

Short communication: Automatic washing of hooves can help control digital dermatitis in dairy cows

The objectives of this study were to develop and test a system for automatic washing of the hooves of dairy cows and to evaluate the effect of frequent automatic washing on the prevalence of digital dermatitis (DD). An automatic hoof washer was developed in an experimental dairy herd and tested in 6 commercial dairy herds in 2 experiments (1 and 2). In the experimental herd, automatic hoof washing resulted in cleaner hooves. In experiments 1 and 2, cows were washed after each milking on the left side only, leaving the right side unwashed as a within-cow control. In experiment 1, hooves were washed with a water and 0.4% soap solution. In experiment 2, hooves were washed with water only. In each experiment, DD was scored in a hoof-trimming chute approximately 60 d after the start of hoof washing. Data were analyzed using a generalized linear mixed model. The outcome was the DD status of each leg (DD positive or DD negative). Herd and cow within herd were included as random effects, and treatment (washing or control) was included as a fixed effect. The statistical analyses showed that the odds ratio of having DD was 1.48 in the control leg compared with the washed leg in experiment 1. In experiment 2, the odds ratio of having DD was 1.27 in the control leg compared with the washed leg. We concluded that automatic washing of hooves with water and soap can help decrease the prevalence of DD in commercial dairy herds.