There is inconclusive and controversial evidence of the association between allergic diseases and the risk of adverse clinical outcomes of coronavirus disease 2019 (COVID-19).
We sought to determine ...the association of allergic disorders with the likelihood of a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test result and with clinical outcomes of COVID-19 (admission to intensive care unit, administration of invasive ventilation, and death).
A propensity-score–matched nationwide cohort study was performed in South Korea. Data obtained from the Health Insurance Review & Assessment Service of Korea from all adult patients (age, >20 years) who were tested for SARS-CoV-2 in South Korea between January 1, 2020, and May 15, 2020, were analyzed. The association of SARS-CoV-2 test positivity and allergic diseases in the entire cohort (n = 219,959) and the difference in clinical outcomes of COVID-19 were evaluated in patients with allergic diseases and SARS-CoV-2 positivity (n = 7,340).
In the entire cohort, patients who underwent SARS-CoV-2 testing were evaluated to ascertain whether asthma and allergic rhinitis were associated with an increased likelihood of SARS-CoV-2 test positivity. After propensity score matching, we found that asthma and allergic rhinitis were associated with worse clinical outcomes of COVID-19 in patients with SARS-CoV-2 test positivity. Patients with nonallergic asthma had a greater risk of SARS-CoV-2 test positivity and worse clinical outcomes of COVID-19 than patients with allergic asthma.
In a Korean nationwide cohort, allergic rhinitis and asthma, especially nonallergic asthma, confers a greater risk of susceptibility to SARS-CoV-2 infection and severe clinical outcomes of COVID-19.
Summary
Background
Moderate‐to‐severe atopic dermatitis (AD) is a chronic disease characterized by intense, persistent and debilitating itch, resulting in sleep deprivation, signs of anxiety and ...depression, impaired quality of life and reduced productivity. The Peak Pruritus Numerical Rating Scale (NRS) was developed and validated as a single‐item, patient‐reported outcome (PRO) of itch severity.
Objectives
To describe the content validity and psychometric assessment (test–retest reliability, construct validity, known‐groups validity, sensitivity to change) of the Peak Pruritus NRS, and to derive empirically a responder definition to identify adults with a meaningful change in itch.
Methods
Content validity was assessed through in‐depth patient interviews. Psychometric assessments used data from phase IIb and phase III dupilumab clinical trials and included test–retest reliability, construct validity, known‐groups validity and sensitivity to change in patients with moderate‐to‐severe AD.
Results
Interview participants indicated that the Peak Pruritus NRS was a relevant, clear and comprehensive assessment of itch severity. Peak Pruritus NRS scores showed large, positive correlations with existing PRO measures of itch, and weak or moderate correlations with clinician‐reported measures assessing objective signs of AD. Peak Pruritus NRS score improvements were highly correlated with improvements in other itch PROs, and moderately correlated with improvements in clinician‐reported measures assessing objective signs of AD. The most appropriate threshold for defining a clinically relevant, within‐person response was ≥ 2–4‐point change in the Peak Pruritus NRS.
Conclusions
The Peak Pruritus NRS is a well‐defined, reliable, sensitive and valid scale for evaluating worst itch intensity in adults with moderate‐to‐severe AD.
What's already known about this topic?
Moderate‐to‐severe atopic dermatitis is characterized by persistent and debilitating itch, which can greatly impair quality of life.
A validated, brief patient‐reported outcome measure is needed to quantify the intensity of itch accurately and reliably in patients with atopic dermatitis in clinical trials.
What does this study add?
The Peak Pruritus Numerical Rating Scale (NRS) is a well‐defined, reliable, fit‐for‐purpose measure to evaluate patient‐reported intensity of worst itch in the previous 24 h for adults with moderate‐to‐severe atopic dermatitis.
Clinical response is indicated by a ≥ 2–4‐point change from baseline in Peak Pruritus NRS score.
What are the clinical implications of this work?
This study provides practising clinicians and clinical trialists with a validated patient‐reported outcome measure to assess itch, a hallmark symptom of atopic dermatitis and a crucial marker of treatment benefit.
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Summary
Atopic dermatitis often precedes the development of other atopic diseases. The atopic march describes this temporal relationship in the natural history of atopic diseases. Although the ...pathophysiological mechanisms that underlie this relationship are poorly understood, epidemiological and genetic data have suggested that the skin might be an important route of sensitization to allergens. Animal models have begun to elucidate how skin barrier defects can lead to systemic allergen sensitization. Emerging data now suggest that epithelial cell‐derived cytokines such as thymic stromal lymphopoietin (TSLP), IL‐33, and IL‐25 may drive the progression from atopic dermatitis to asthma and food allergy. This review focuses on current concepts of the role of skin barrier defects and epithelial cell‐derived cytokines in the initiation and maintenance of allergic inflammation and the atopic march.
Atopic dermatitis is a chronic inflammatory skin disorder characterized by defects in the epidermal barrier and keratinocyte differentiation. The expression of filaggrin, a protein thought to have a ...major role in the function of the epidermis, is downregulated. However, the impact of this deficiency on keratinocytes is not really known. This was investigated using lentivirus-mediated small-hairpin RNA interference in a three-dimensional reconstructed human epidermis (RHE) model, in the absence of other cell types than keratinocytes. Similar to what is known for atopic skin, the experimental filaggrin downregulation resulted in hypogranulosis, a disturbed corneocyte intracellular matrix, reduced amounts of natural moisturizing factor components, increased permeability and UV-B sensitivity of the RHE, and impaired keratinocyte differentiation at the messenger RNA and protein levels. In particular, the amounts of two filaggrin-related proteins and one protease involved in the degradation of filaggrin, bleomycin hydrolase, were lower. In addition, caspase-14 activation was reduced. These results demonstrate the importance of filaggrin for the stratum corneum properties/functions. They indicate that filaggrin downregulation in the epidermis of atopic patients, either acquired or innate, may be directly responsible for some of the disease-related alterations in the epidermal differentiation program and epidermal barrier function.
Allergic skin diseases, such as atopic dermatitis, are clinically characterized by severe itching and type 2 immunity-associated hypersensitivity to widely distributed allergens, including those ...derived from house dust mites (HDMs). Here we found that HDMs with cysteine protease activity directly activated peptidergic nociceptors, which are neuropeptide-producing nociceptive sensory neurons that express the ion channel TRPV1 and Tac1, the gene encoding the precursor for the neuropeptide substance P. Intravital imaging and genetic approaches indicated that HDM-activated nociceptors drive the development of allergic skin inflammation by inducing the degranulation of mast cells contiguous to such nociceptors, through the release of substance P and the activation of the cationic molecule receptor MRGPRB2 on mast cells. These data indicate that, after exposure to HDM allergens, activation of TRPV1
Tac1
nociceptor-MRGPRB2
mast cell sensory clusters represents a key early event in the development of allergic skin reactions.
To summarize studies investigating ethnical and racial differences in atopic dermatitis (AD) epidemiology, clinical features, and skin and blood phenotypes.
PubMed literature review (years ...2000-2018).
Articles discussing primarily human disease.
Higher overall rates of AD were found in Africa and Oceania as opposed to India and Northern and Eastern Europe. In the United States, AD prevalence was found to be higher in African American (19.3%) compared with European American (16.1%) children. Although several studies have consistently found FLG loss-of-function mutations in up to 50% of European and 27% of Asian patients with AD, FLG mutations were 6 times less common in African American than in European American patients, even in patients with severe AD. Thus, FLG mutations seem to play less a pathogenic role in patients of African origin than in individuals of European or Asian ancestry. The immune phenotype of all ethnic groups was characterized by strong T
2 activation, but important differences in immune polarization exist among the different ethnicities. Asian patients with AD had stronger T
17/T
22 activation than African American and European American patients with AD, whereas African American patients had the highest serum IgE levels among all groups, while largely lacking T
1 and T
17 activation.
AD is a heterogeneous disease that has differences among various ethnic and racial groups, which might be important for the development of future, targeted treatments and for personalized medicine approaches.
The skin represents the largest organ of the body and provides a vital interface between the body and the environment. Hereditary and acquired alterations of structural proteins and lipids of the ...stratum corneum and epidermal tight junctions leading to a diminished skin barrier function are major causative factors for a number of skin diseases, in particular atopic dermatitis (AD). This review summarizes current knowledge on the role of the skin barrier in AD with regard to pathogenesis and treatment, on the relationship between skin barrier abnormalities and immune aberrations, and on potential therapies aimed at repair of the skin barrier. Furthermore recent advances in the genetics of AD will be addressed.
Increased presence of IL-22+ cells in the skin is a characteristic finding in skin barrier defects, such as psoriasis and atopic dermatitis. However, mechanistic insight into effects of IL-22 on ...epidermal functioning is yet to be elucidated. One crucial step during epidermal differentiation is deimination or citrullination. Here, we show reduced levels of peptidylarginine deiminase 1, an enzyme that converts peptidylarginine into citrulline in lesional psoriatic skin. IL-22 signaling through the IL-22 receptor complex was found to suppress expression of peptidylarginine deiminase 1 in epidermal keratinocytes. Subsequently, total peptidylarginine deiminase activity and extent of protein deimination in keratinocytes treated with IL-22 were reduced together with a significant decrease in deimination of keratin 1 and FLG, both important for epidermal differentiation. Vitamin D and acitretin partly restored the peptidylarginine deiminase 1 defect caused by IL-22. Collectively, we show that IL-22 downregulates deimination, thus identifying a potential target for treatment of skin barrier defects.
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Atopic dermatitis (AD) is a common and relapsing skin disease that is characterized by skin barrier dysfunction, inflammation, and chronic pruritus. While AD was previously thought to occur primarily ...in children, increasing evidence suggests that AD is more common in adults than previously assumed. Accumulating evidence from experimental, genetic, and clinical studies indicates that AD expression is a precondition for the later development of other atopic diseases, such as asthma, food allergies, and allergic rhinitis. Although the exact mechanisms of the disease pathogenesis remain unclear, it is evident that both cutaneous barrier dysfunction and immune dysregulation are critical etiologies of AD pathology. This review explores recent findings on AD and the possible underlying mechanisms involved in its pathogenesis, which is characterized by dysregulation of immunological and skin barrier integrity and function, supporting the idea that AD is a systemic disease. These findings provide further insights for therapeutic developments aiming to repair the skin barrier and decrease inflammation.
Summary Atopic dermatitis (also known as atopic eczema) is a chronic inflammatory skin disease that is characterised by intense itching and recurrent eczematous lesions. Although it most often starts ...in infancy and affects two of ten children, it is also highly prevalent in adults. It is the leading non-fatal health burden attributable to skin diseases, inflicts a substantial psychosocial burden on patients and their relatives, and increases the risk of food allergy, asthma, allergic rhinitis, other immune-mediated inflammatory diseases, and mental health disorders. Originally regarded as a childhood disorder mediated by an imbalance towards a T-helper-2 response and exaggerated IgE responses to allergens, it is now recognised as a lifelong disposition with variable clinical manifestations and expressivity, in which defects of the epidermal barrier are central. Present prevention and treatment focus on restoration of epidermal barrier function, which is best achieved through the use of emollients. Topical corticosteroids are still the first-line therapy for acute flares, but they are also used proactively along with topical calcineurin inhibitors to maintain remission. Non-specific immunosuppressive drugs are used in severe refractory cases, but targeted disease-modifying drugs are being developed. We need to improve understanding of the heterogeneity of the disease and its subtypes, the role of atopy and autoimmunity, the mechanisms behind disease-associated itch, and the comparative effectiveness and safety of therapies.
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